Title: Chat with Large Language Models
Version: 0.4.0
Description: Chat with large language models from a range of providers including 'Claude' https://claude.ai, 'OpenAI' https://chatgpt.com, and more. Supports streaming, asynchronous calls, tool calling, and structured data extraction.
License: MIT + file LICENSE
URL: https://ellmer.tidyverse.org, https://github.com/tidyverse/ellmer
BugReports: https://github.com/tidyverse/ellmer/issues
Depends: R (≥ 4.1)
Imports: cli, coro (≥ 1.1.0), glue, httr2 (≥ 1.2.1), jsonlite, later (≥ 1.4.0), lifecycle, promises (≥ 1.3.1), R6, rlang (≥ 1.1.0), S7 (≥ 0.2.0), tibble, vctrs
Suggests: connectcreds, curl (≥ 6.0.1), gargle, gitcreds, jose, knitr, magick, openssl, paws.common, png, rmarkdown, shiny, shinychat (≥ 0.2.0), testthat (≥ 3.0.0), vcr (≥ 2.0.0), withr
VignetteBuilder: knitr
Config/Needs/website: tidyverse/tidytemplate, rmarkdown
Config/testthat/edition: 3
Config/testthat/parallel: true
Config/testthat/start-first: chat, provider*
Encoding: UTF-8
RoxygenNote: 7.3.3
Collate: 'utils-S7.R' 'types.R' 'ellmer-package.R' 'tools-def.R' 'content.R' 'provider.R' 'as-json.R' 'batch-chat.R' 'chat-structured.R' 'chat-tools-content.R' 'turns.R' 'chat-tools.R' 'chat-utils.R' 'utils-coro.R' 'chat.R' 'content-image.R' 'content-pdf.R' 'content-replay.R' 'httr2.R' 'import-standalone-obj-type.R' 'import-standalone-purrr.R' 'import-standalone-types-check.R' 'interpolate.R' 'live.R' 'parallel-chat.R' 'params.R' 'provider-any.R' 'provider-aws.R' 'provider-openai-compatible.R' 'provider-azure.R' 'provider-claude-files.R' 'provider-claude-tools.R' 'provider-claude.R' 'provider-google.R' 'provider-cloudflare.R' 'provider-databricks.R' 'provider-deepseek.R' 'provider-github.R' 'provider-google-tools.R' 'provider-google-upload.R' 'provider-groq.R' 'provider-huggingface.R' 'provider-mistral.R' 'provider-ollama.R' 'provider-openai-tools.R' 'provider-openai.R' 'provider-openrouter.R' 'provider-perplexity.R' 'provider-portkey.R' 'provider-snowflake.R' 'provider-vllm.R' 'schema.R' 'tokens.R' 'tools-built-in.R' 'tools-def-auto.R' 'utils-auth.R' 'utils-callbacks.R' 'utils-cat.R' 'utils-merge.R' 'utils-prettytime.R' 'utils.R' 'zzz.R'
NeedsCompilation: no
Packaged: 2025-11-14 20:31:09 UTC; hadleywickham
Author: Hadley Wickham ORCID iD [aut, cre], Joe Cheng [aut], Aaron Jacobs [aut], Garrick Aden-Buie ORCID iD [aut], Barret Schloerke ORCID iD [aut], Posit Software, PBC ROR ID [cph, fnd]
Maintainer: Hadley Wickham <hadley@posit.co>
Repository: CRAN
Date/Publication: 2025-11-15 12:00:16 UTC

ellmer: Chat with Large Language Models

Description

logo

Chat with large language models from a range of providers including 'Claude' https://claude.ai, 'OpenAI' https://chatgpt.com, and more. Supports streaming, asynchronous calls, tool calling, and structured data extraction.

Author(s)

Maintainer: Hadley Wickham hadley@posit.co (ORCID)

Authors:

Other contributors:

See Also

Useful links:


The Chat object

Description

A Chat is a sequence of user and assistant Turns sent to a specific Provider. A Chat is a mutable R6 object that takes care of managing the state associated with the chat; i.e. it records the messages that you send to the server, and the messages that you receive back. If you register a tool (i.e. an R function that the assistant can call on your behalf), it also takes care of the tool loop.

You should generally not create this object yourself, but instead call chat_openai() or friends instead.

Value

A Chat object

Methods

Public methods


Method new()

Usage
Chat$new(provider, system_prompt = NULL, echo = "none")
Arguments
provider

A provider object.

system_prompt

System prompt to start the conversation with.

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method. You can override the default by setting the ellmer_echo option.


Method get_turns()

Retrieve the turns that have been sent and received so far (optionally starting with the system prompt, if any).

Usage
Chat$get_turns(include_system_prompt = FALSE)
Arguments
include_system_prompt

Whether to include the system prompt in the turns (if any exists).


Method set_turns()

Replace existing turns with a new list.

Usage
Chat$set_turns(value)
Arguments
value

A list of Turns.


Method add_turn()

Add a pair of turns to the chat.

Usage
Chat$add_turn(user, assistant, log_tokens = TRUE)
Arguments
user

The user Turn.

assistant

The system Turn.

log_tokens

Should tokens used in the turn be logged to the session counter?


Method get_system_prompt()

If set, the system prompt, it not, NULL.

Usage
Chat$get_system_prompt()

Method get_model()

Retrieve the model name

Usage
Chat$get_model()

Method set_system_prompt()

Update the system prompt

Usage
Chat$set_system_prompt(value)
Arguments
value

A character vector giving the new system prompt


Method get_tokens()

A data frame with token usage and cost data. There are four columns: input, output, cached_input, and cost. There is one row for each assistant turn, because token counts and costs are only available when the API returns the assistant's response.

Usage
Chat$get_tokens(include_system_prompt = deprecated())
Arguments
include_system_prompt

[Deprecated]


Method get_cost()

The cost of this chat

Usage
Chat$get_cost(include = c("all", "last"))
Arguments
include

The default, "all", gives the total cumulative cost of this chat. Alternatively, use "last" to get the cost of just the most recent turn.


Method last_turn()

The last turn returned by the assistant.

Usage
Chat$last_turn(role = c("assistant", "user", "system"))
Arguments
role

Optionally, specify a role to find the last turn with for the role.

Returns

Either a Turn or NULL, if no turns with the specified role have occurred.


Method chat()

Submit input to the chatbot, and return the response as a simple string (probably Markdown).

Usage
Chat$chat(..., echo = NULL)
Arguments
...

The input to send to the chatbot. Can be strings or images (see content_image_file() and content_image_url().

echo

Whether to emit the response to stdout as it is received. If NULL, then the value of echo set when the chat object was created will be used.


Method chat_structured()

Extract structured data

Usage
Chat$chat_structured(..., type, echo = "none", convert = TRUE)
Arguments
...

The input to send to the chatbot. This is typically the text you want to extract data from, but it can be omitted if the data is obvious from the existing conversation.

type

A type specification for the extracted data. Should be created with a type_() function.

echo

Whether to emit the response to stdout as it is received. Set to "text" to stream JSON data as it's generated (not supported by all providers).

convert

Automatically convert from JSON lists to R data types using the schema. For example, this will turn arrays of objects into data frames and arrays of strings into a character vector.


Method chat_structured_async()

Extract structured data, asynchronously. Returns a promise that resolves to an object matching the type specification.

Usage
Chat$chat_structured_async(..., type, echo = "none", convert = TRUE)
Arguments
...

The input to send to the chatbot. Will typically include the phrase "extract structured data".

type

A type specification for the extracted data. Should be created with a type_() function.

echo

Whether to emit the response to stdout as it is received. Set to "text" to stream JSON data as it's generated (not supported by all providers).

convert

Automatically convert from JSON lists to R data types using the schema. For example, this will turn arrays of objects into data frames and arrays of strings into a character vector.


Method chat_async()

Submit input to the chatbot, and receive a promise that resolves with the response all at once. Returns a promise that resolves to a string (probably Markdown).

Usage
Chat$chat_async(..., tool_mode = c("concurrent", "sequential"))
Arguments
...

The input to send to the chatbot. Can be strings or images.

tool_mode

Whether tools should be invoked one-at-a-time ("sequential") or concurrently ("concurrent"). Sequential mode is best for interactive applications, especially when a tool may involve an interactive user interface. Concurrent mode is the default and is best suited for automated scripts or non-interactive applications.


Method stream()

Submit input to the chatbot, returning streaming results. Returns A coro generator that yields strings. While iterating, the generator will block while waiting for more content from the chatbot.

Usage
Chat$stream(..., stream = c("text", "content"))
Arguments
...

The input to send to the chatbot. Can be strings or images.

stream

Whether the stream should yield only "text" or ellmer's rich content types. When stream = "content", stream() yields Content objects.


Method stream_async()

Submit input to the chatbot, returning asynchronously streaming results. Returns a coro async generator that yields string promises.

Usage
Chat$stream_async(
  ...,
  tool_mode = c("concurrent", "sequential"),
  stream = c("text", "content")
)
Arguments
...

The input to send to the chatbot. Can be strings or images.

tool_mode

Whether tools should be invoked one-at-a-time ("sequential") or concurrently ("concurrent"). Sequential mode is best for interactive applications, especially when a tool may involve an interactive user interface. Concurrent mode is the default and is best suited for automated scripts or non-interactive applications.

stream

Whether the stream should yield only "text" or ellmer's rich content types. When stream = "content", stream() yields Content objects.


Method register_tool()

Register a tool (an R function) that the chatbot can use. Learn more in vignette("tool-calling").

Usage
Chat$register_tool(tool)
Arguments
tool

A tool definition created by tool().


Method register_tools()

Register a list of tools. Learn more in vignette("tool-calling").

Usage
Chat$register_tools(tools)
Arguments
tools

A list of tool definitions created by tool().


Method get_provider()

Get the underlying provider object. For expert use only.

Usage
Chat$get_provider()

Method get_tools()

Retrieve the list of registered tools.

Usage
Chat$get_tools()

Method set_tools()

Sets the available tools. For expert use only; most users should use register_tool().

Usage
Chat$set_tools(tools)
Arguments
tools

A list of tool definitions created with tool().


Method on_tool_request()

Register a callback for a tool request event.

Usage
Chat$on_tool_request(callback)
Arguments
callback

A function to be called when a tool request event occurs, which must have request as its only argument.

Returns

A function that can be called to remove the callback.


Method on_tool_result()

Register a callback for a tool result event.

Usage
Chat$on_tool_result(callback)
Arguments
callback

A function to be called when a tool result event occurs, which must have result as its only argument.

Returns

A function that can be called to remove the callback.


Method clone()

The objects of this class are cloneable with this method.

Usage
Chat$clone(deep = FALSE)
Arguments
deep

Whether to make a deep clone.

Examples


chat <- chat_openai()
chat$chat("Tell me a funny joke")


Content types received from and sent to a chatbot

Description

Use these functions if you're writing a package that extends ellmer and need to customise methods for various types of content. For normal use, see content_image_url() and friends.

ellmer abstracts away differences in the way that different Providers represent various types of content, allowing you to more easily write code that works with any chatbot. This set of classes represents types of content that can be either sent to and received from a provider:

Usage

Content()

ContentText(text = stop("Required"))

ContentImage()

ContentImageRemote(url = stop("Required"), detail = "")

ContentImageInline(type = stop("Required"), data = NULL)

ContentToolRequest(
  id = stop("Required"),
  name = stop("Required"),
  arguments = list(),
  tool = NULL
)

ContentToolResult(value = NULL, error = NULL, extra = list(), request = NULL)

ContentThinking(thinking = stop("Required"), extra = list())

ContentPDF(
  type = stop("Required"),
  data = stop("Required"),
  filename = stop("Required")
)

Arguments

text

A single string.

url

URL to a remote image.

detail

Not currently used.

type

MIME type of the image.

data

Base64 encoded image data.

id

Tool call id (used to associate a request and a result). Automatically managed by ellmer.

name

Function name

arguments

Named list of arguments to call the function with.

tool

ellmer automatically matches a tool request to the tools defined for the chatbot. If NULL, the request did not match a defined tool.

value

The results of calling the tool function, if it succeeded.

error

The error message, as a string, or the error condition thrown as a result of a failure when calling the tool function. Must be NULL when the tool call is successful.

extra

Additional data.

request

The ContentToolRequest associated with the tool result, automatically added by ellmer when evaluating the tool call.

thinking

The text of the thinking output.

filename

File name, used to identify the PDF.

Value

S7 objects that all inherit from Content

Examples

Content()
ContentText("Tell me a joke")
ContentImageRemote("https://www.r-project.org/Rlogo.png")
ContentToolRequest(id = "abc", name = "mean", arguments = list(x = 1:5))

A chatbot provider

Description

A Provider captures the details of one chatbot service/API. This captures how the API works, not the details of the underlying large language model. Different providers might offer the same (open source) model behind a different API.

Usage

Provider(
  name = stop("Required"),
  model = stop("Required"),
  base_url = stop("Required"),
  params = list(),
  extra_args = list(),
  extra_headers = character(0),
  credentials = function() NULL
)

Arguments

name

Name of the provider.

model

Name of the model.

base_url

The base URL for the API.

params

A list of standard parameters created by params().

extra_args

Arbitrary extra arguments to be included in the request body.

extra_headers

Arbitrary extra headers to be added to the request.

credentials

A zero-argument function that returns the credentials to use for authentication. Can either return a string, representing an API key, or a named list of headers.

Details

To add support for a new backend, you will need to subclass Provider (adding any additional fields that your provider needs) and then implement the various generics that control the behavior of each provider.

Value

An S7 Provider object.

Examples

Provider(
  name = "CoolModels",
  model = "my_model",
  base_url = "https://cool-models.com"
)

A user, assistant, or system turn

Description

Every conversation with a chatbot consists of pairs of user and assistant turns, corresponding to an HTTP request and response. These turns are represented by the Turn object, which contains a list of Contents representing the individual messages within the turn. These might be text, images, tool requests (assistant only), or tool responses (user only).

UserTurn, AssistantTurn, and SystemTurn are specialized subclasses of Turn for different types of conversation turns. AssistantTurn includes additional metadata about the API response.

Note that a call to ⁠$chat()⁠ and related functions may result in multiple user-assistant turn cycles. For example, if you have registered tools, ellmer will automatically handle the tool calling loop, which may result in any number of additional cycles. Learn more about tool calling in vignette("tool-calling").

Usage

Turn(role = NULL, contents = list(), tokens = NULL)

UserTurn(contents = list())

SystemTurn(contents = list())

AssistantTurn(
  contents = list(),
  json = list(),
  tokens = c(NA_real_, NA_real_, NA_real_),
  cost = NA_real_,
  duration = NA_real_
)

Arguments

role

[Deprecated] For system, user and assistant turns, use SystemTurn(), UserTurn(), and AssistantTurn(), respectively.

contents

A list of Content objects.

tokens

A numeric vector of length 3 representing the number of input tokens (uncached), output tokens, and input tokens (cached) used in this turn.

json

The serialized JSON corresponding to the underlying data of the turns. This is useful if there's information returned by the provider that ellmer doesn't otherwise expose.

cost

The cost of the turn in dollars.

duration

The duration of the request in seconds.

Value

An S7 Turn object

An S7 AssistantTurn object

Examples

UserTurn(list(ContentText("Hello, world!")))

Type definitions for function calling and structured data extraction.

Description

These S7 classes are provided for use by package devlopers who are extending ellmer. In every day use, use type_boolean() and friends.

Usage

TypeBasic(description = NULL, required = TRUE, type = stop("Required"))

TypeEnum(description = NULL, required = TRUE, values = character(0))

TypeArray(description = NULL, required = TRUE, items = Type())

TypeJsonSchema(description = NULL, required = TRUE, json = list())

TypeIgnore(description = NULL, required = TRUE)

TypeObject(
  description = NULL,
  required = TRUE,
  properties = list(),
  additional_properties = FALSE
)

Arguments

description

The purpose of the component. This is used by the LLM to determine what values to pass to the tool or what values to extract in the structured data, so the more detail that you can provide here, the better.

required

Is the component or argument required?

In type descriptions for structured data, if required = FALSE and the component does not exist in the data, the LLM may hallucinate a value. Only applies when the element is nested inside of a type_object().

In tool definitions, required = TRUE signals that the LLM should always provide a value. Arguments with required = FALSE should have a default value in the tool function's definition. If the LLM does not provide a value, the default value will be used.

type

Basic type name. Must be one of boolean, integer, number, or string.

values

Character vector of permitted values.

items

The type of the array items. Can be created by any of the type_ function.

json

A JSON schema object as a list.

properties

Named list of properties stored inside the object. Each element should be an S7 Type object.'

additional_properties

Can the object have arbitrary additional properties that are not explicitly listed? Only supported by Claude.

Value

S7 objects inheriting from Type

Examples

TypeBasic(type = "boolean")
TypeArray(items = TypeBasic(type = "boolean"))

Submit multiple chats in one batch

Description

batch_chat() and batch_chat_structured() currently only work with chat_openai() and chat_anthropic(). They use the OpenAI and Anthropic batch APIs which allow you to submit multiple requests simultaneously. The results can take up to 24 hours to complete, but in return you pay 50% less than usual (but note that ellmer doesn't include this discount in its pricing metadata). If you want to get results back more quickly, or you're working with a different provider, you may want to use parallel_chat() instead.

Since batched requests can take a long time to complete, batch_chat() requires a file path that is used to store information about the batch so you never lose any work. You can either set wait = FALSE or simply interrupt the waiting process, then later, either call batch_chat() to resume where you left off or call batch_chat_completed() to see if the results are ready to retrieve. batch_chat() will store the chat responses in this file, so you can either keep it around to cache the results, or delete it to free up disk space.

This API is marked as experimental since I don't yet know how to handle errors in the most helpful way. Fortunately they don't seem to be common, but if you have ideas, please let me know!

Usage

batch_chat(chat, prompts, path, wait = TRUE, ignore_hash = FALSE)

batch_chat_text(chat, prompts, path, wait = TRUE, ignore_hash = FALSE)

batch_chat_structured(
  chat,
  prompts,
  path,
  type,
  wait = TRUE,
  ignore_hash = FALSE,
  convert = TRUE,
  include_tokens = FALSE,
  include_cost = FALSE
)

batch_chat_completed(chat, prompts, path)

Arguments

chat

A chat object created by a chat_ function, or a string passed to chat().

prompts

A vector created by interpolate() or a list of character vectors.

path

Path to file (with .json extension) to store state.

The file records a hash of the provider, the prompts, and the existing chat turns. If you attempt to reuse the same file with any of these being different, you'll get an error.

wait

If TRUE, will wait for batch to complete. If FALSE, it will return NULL if the batch is not complete, and you can retrieve the results later by re-running batch_chat() when batch_chat_completed() is TRUE.

ignore_hash

If TRUE, will only warn rather than error when the hash doesn't match. You can use this if ellmer has changed the hash structure and you're confident that you're reusing the same inputs.

type

A type specification for the extracted data. Should be created with a type_() function.

convert

If TRUE, automatically convert from JSON lists to R data types using the schema. This typically works best when type is type_object() as this will give you a data frame with one column for each property. If FALSE, returns a list.

include_tokens

If TRUE, and the result is a data frame, will add input_tokens and output_tokens columns giving the total input and output tokens for each prompt.

include_cost

If TRUE, and the result is a data frame, will add cost column giving the cost of each prompt.

Value

For batch_chat(), a list of Chat objects, one for each prompt. For batch_chat_test(), a character vector of text responses. For batch_chat_structured(), a single structured data object with one element for each prompt. Typically, when type is an object, this will will be a data frame with one row for each prompt, and one column for each property.

For any of the aboves, will return NULL if wait = FALSE and the job is not complete.

Examples


chat <- chat_openai(model = "gpt-4.1-nano")

# Chat ----------------------------------------------------------------------

prompts <- interpolate("What do people from {{state.name}} bring to a potluck dinner?")
## Not run: 
chats <- batch_chat(chat, prompts, path = "potluck.json")
chats

## End(Not run)

# Structured data -----------------------------------------------------------
prompts <- list(
  "I go by Alex. 42 years on this planet and counting.",
  "Pleased to meet you! I'm Jamal, age 27.",
  "They call me Li Wei. Nineteen years young.",
  "Fatima here. Just celebrated my 35th birthday last week.",
  "The name's Robert - 51 years old and proud of it.",
  "Kwame here - just hit the big 5-0 this year."
)
type_person <- type_object(name = type_string(), age = type_number())
## Not run: 
data <- batch_chat_structured(
  chat = chat,
  prompts = prompts,
  path = "people-data.json",
  type = type_person
)
data

## End(Not run)


Chat with any provider

Description

This is a generic interface to all the other chat_ functions that allow to you pick the provider and the model with a simple string.

Usage

chat(
  name,
  ...,
  system_prompt = NULL,
  params = NULL,
  echo = c("none", "output", "all")
)

Arguments

name

Provider (and optionally model) name in the form "provider/model" or "provider" (which will use the default model for that provider).

...

Arguments passed to the provider function.

system_prompt

A system prompt to set the behavior of the assistant.

params

Common model parameters, usually created by params().

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.


Chat with an Anthropic Claude model

Description

Anthropic provides a number of chat based models under the Claude moniker. Note that a Claude Pro membership does not give you the ability to call models via the API; instead, you will need to sign up (and pay for) a developer account.

Usage

chat_anthropic(
  system_prompt = NULL,
  params = NULL,
  model = NULL,
  cache = c("5m", "1h", "none"),
  api_args = list(),
  base_url = "https://api.anthropic.com/v1",
  beta_headers = character(),
  api_key = NULL,
  credentials = NULL,
  api_headers = character(),
  echo = NULL
)

chat_claude(
  system_prompt = NULL,
  params = NULL,
  model = NULL,
  cache = c("5m", "1h", "none"),
  api_args = list(),
  base_url = "https://api.anthropic.com/v1",
  beta_headers = character(),
  api_key = NULL,
  credentials = NULL,
  api_headers = character(),
  echo = NULL
)

models_claude(
  base_url = "https://api.anthropic.com/v1",
  api_key = anthropic_key()
)

models_anthropic(
  base_url = "https://api.anthropic.com/v1",
  api_key = anthropic_key()
)

Arguments

system_prompt

A system prompt to set the behavior of the assistant.

params

Common model parameters, usually created by params().

model

The model to use for the chat (defaults to "claude-sonnet-4-5-20250929"). We regularly update the default, so we strongly recommend explicitly specifying a model for anything other than casual use. Use models_anthropic() to see all options.

cache

How long to cache inputs? Defaults to "5m" (five minutes). Set to "none" to disable caching or "1h" to cache for one hour.

See details below.

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

base_url

The base URL to the endpoint; the default is Claude's public API.

beta_headers

Optionally, a character vector of beta headers to opt-in claude features that are still in beta.

api_key

[Deprecated] Use credentials instead.

credentials

Override the default credentials. You generally should not need this argument; instead set the ANTHROPIC_API_KEY environment variable. The best place to set this is in .Renviron, which you can easily edit by calling usethis::edit_r_environ().

If you do need additional control, this argument takes a zero-argument function that returns either a string (the API key), or a named list (added as additional headers to every request).

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

Value

A Chat object.

Caching

Caching with Claude is a bit more complicated than other providers but we believe that on average it will save you both money and time, so we have enabled it by default. With other providers, like OpenAI and Google, you only pay for cache reads, which cost 10% of the normal price. With Claude, you also pay for cache writes, which cost 125% of the normal price for 5 minute caching and 200% of the normal price for 1 hour caching.

How does this affect the total cost of a conversation? Imagine the first turn sends 1000 input tokens and receives 200 output tokens. The second turn must first send both the input and output from the previous turn (1200 tokens). It then sends a further 1000 tokens and receives 200 tokens back.

To compare the prices of these two approaches we can ignore the cost of output tokens, because they are the same for both. How much will the input tokens cost? If we don't use caching, we send 1000 tokens in the first turn and 2200 (1000 + 200 + 1000) tokens in the second turn for a total of 3200 tokens. If we use caching, we'll send (the equivalent of) 1000 * 1.25 = 1250 tokens in the first turn. In the second turn, 1000 of the input tokens will be cached so the total cost is 1000 * 0.1 + (200 + 1000) * 1.25 = 1600 tokens. That makes a total of 2850 tokens, i.e. 11% fewer tokens, decreasing the overall cost.

Obviously, the details will vary from conversation to conversation, but if you have a large system prompt that you re-use many times you should expect to see larger savings. You can see exactly how many input and cache input tokens each turn uses, along with the total cost, with chat$get_tokens(). If you don't see savings for your use case, you can suppress caching with cache = "none".

I know this is already quite complicated, but there's one final wrinkle: Claude will only cache longer prompts, with caching requiring at least 1024-4096 tokens, depending on the model. So don't be surprised it if you don't see any differences with caching if you have a short prompt.

See all the details at https://docs.claude.com/en/docs/build-with-claude/prompt-caching.

See Also

Other chatbots: chat_aws_bedrock(), chat_azure_openai(), chat_cloudflare(), chat_databricks(), chat_deepseek(), chat_github(), chat_google_gemini(), chat_groq(), chat_huggingface(), chat_mistral(), chat_ollama(), chat_openai(), chat_openai_compatible(), chat_openrouter(), chat_perplexity(), chat_portkey()

Examples


chat <- chat_anthropic()
chat$chat("Tell me three jokes about statisticians")


Chat with an AWS bedrock model

Description

AWS Bedrock provides a number of language models, including those from Anthropic's Claude, using the Bedrock Converse API.

Authentication

Authentication is handled through {paws.common}, so if authentication does not work for you automatically, you'll need to follow the advice at https://www.paws-r-sdk.com/#credentials. In particular, if your org uses AWS SSO, you'll need to run ⁠aws sso login⁠ at the terminal.

Usage

chat_aws_bedrock(
  system_prompt = NULL,
  base_url = NULL,
  model = NULL,
  profile = NULL,
  params = NULL,
  api_args = list(),
  api_headers = character(),
  echo = NULL
)

models_aws_bedrock(profile = NULL, base_url = NULL)

Arguments

system_prompt

A system prompt to set the behavior of the assistant.

base_url

The base URL to the endpoint; the default is OpenAI's public API.

model

The model to use for the chat (defaults to "anthropic.claude-sonnet-4-5-20250929-v1:0"). We regularly update the default, so we strongly recommend explicitly specifying a model for anything other than casual use. Use models_models_aws_bedrock() to see all options. .

While ellmer provides a default model, there's no guarantee that you'll have access to it, so you'll need to specify a model that you can. If you're using cross-region inference, you'll need to use the inference profile ID, e.g. model="us.anthropic.claude-sonnet-4-5-20250929-v1:0".

profile

AWS profile to use.

params

Common model parameters, usually created by params().

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Some useful arguments include:

api_args = list(
  inferenceConfig = list(
    maxTokens = 100,
    temperature = 0.7,
    topP = 0.9,
    topK = 20
  )
)
api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_azure_openai(), chat_cloudflare(), chat_databricks(), chat_deepseek(), chat_github(), chat_google_gemini(), chat_groq(), chat_huggingface(), chat_mistral(), chat_ollama(), chat_openai(), chat_openai_compatible(), chat_openrouter(), chat_perplexity(), chat_portkey()

Examples

## Not run: 
# Basic usage
chat <- chat_aws_bedrock()
chat$chat("Tell me three jokes about statisticians")

## End(Not run)

Chat with a model hosted on Azure OpenAI

Description

The Azure OpenAI server hosts a number of open source models as well as proprietary models from OpenAI.

Built on top of chat_openai_compatible().

Authentication

chat_azure_openai() supports API keys and the credentials parameter, but it also makes use of:

Usage

chat_azure_openai(
  endpoint = azure_endpoint(),
  model,
  params = NULL,
  api_version = NULL,
  system_prompt = NULL,
  api_key = NULL,
  credentials = NULL,
  api_args = list(),
  echo = c("none", "output", "all"),
  api_headers = character(),
  deployment_id = deprecated()
)

Arguments

endpoint

Azure OpenAI endpoint url with protocol and hostname, i.e. ⁠https://{your-resource-name}.openai.azure.com⁠. Defaults to using the value of the AZURE_OPENAI_ENDPOINT environment variable.

model

The deployment id for the model you want to use.

params

Common model parameters, usually created by params().

api_version

The API version to use.

system_prompt

A system prompt to set the behavior of the assistant.

api_key

[Deprecated] Use credentials instead.

credentials

Override the default credentials. You generally should not need this argument; instead set the AZURE_OPENAI_API_KEY environment variable. The best place to set this is in .Renviron, which you can easily edit by calling usethis::edit_r_environ().

If you do need additional control, this argument takes a zero-argument function that returns either a string (the API key), or a named list (added as additional headers to every request).

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

deployment_id

[Deprecated] Use model instead.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_aws_bedrock(), chat_cloudflare(), chat_databricks(), chat_deepseek(), chat_github(), chat_google_gemini(), chat_groq(), chat_huggingface(), chat_mistral(), chat_ollama(), chat_openai(), chat_openai_compatible(), chat_openrouter(), chat_perplexity(), chat_portkey()

Examples

## Not run: 
chat <- chat_azure_openai(model = "gpt-4o-mini")
chat$chat("Tell me three jokes about statisticians")

## End(Not run)

Chat with a model hosted on CloudFlare

Description

Cloudflare Workers AI hosts a variety of open-source AI models. To use the Cloudflare API, you must have an Account ID and an Access Token, which you can obtain by following these instructions.

Built on top of chat_openai_compatible().

Known limitations

Usage

chat_cloudflare(
  account = cloudflare_account(),
  system_prompt = NULL,
  params = NULL,
  api_key = NULL,
  credentials = NULL,
  model = NULL,
  api_args = list(),
  echo = NULL,
  api_headers = character()
)

Arguments

account

The Cloudflare account ID. Taken from the CLOUDFLARE_ACCOUNT_ID env var, if defined.

system_prompt

A system prompt to set the behavior of the assistant.

params

Common model parameters, usually created by params().

api_key

[Deprecated] Use credentials instead.

credentials

Override the default credentials. You generally should not need this argument; instead set the CLOUDFLARE_API_KEY environment variable. The best place to set this is in .Renviron, which you can easily edit by calling usethis::edit_r_environ().

If you do need additional control, this argument takes a zero-argument function that returns either a string (the API key), or a named list (added as additional headers to every request).

model

The model to use for the chat (defaults to "meta-llama/Llama-3.3-70b-instruct-fp8-fast"). We regularly update the default, so we strongly recommend explicitly specifying a model for anything other than casual use.

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_aws_bedrock(), chat_azure_openai(), chat_databricks(), chat_deepseek(), chat_github(), chat_google_gemini(), chat_groq(), chat_huggingface(), chat_mistral(), chat_ollama(), chat_openai(), chat_openai_compatible(), chat_openrouter(), chat_perplexity(), chat_portkey()

Examples

## Not run: 
chat <- chat_cloudflare()
chat$chat("Tell me three jokes about statisticians")

## End(Not run)

Chat with a model hosted on Databricks

Description

Databricks provides out-of-the-box access to a number of foundation models and can also serve as a gateway for external models hosted by a third party.

Built on top of chat_openai_compatible().

Authentication

chat_databricks() picks up on ambient Databricks credentials for a subset of the Databricks client unified authentication model. Specifically, it supports:

Usage

chat_databricks(
  workspace = databricks_workspace(),
  system_prompt = NULL,
  model = NULL,
  token = NULL,
  params = NULL,
  api_args = list(),
  echo = c("none", "output", "all"),
  api_headers = character()
)

Arguments

workspace

The URL of a Databricks workspace, e.g. "https://example.cloud.databricks.com". Will use the value of the environment variable DATABRICKS_HOST, if set.

system_prompt

A system prompt to set the behavior of the assistant.

model

The model to use for the chat (defaults to "databricks-claude-3-7-sonnet"). We regularly update the default, so we strongly recommend explicitly specifying a model for anything other than casual use.

Available foundational models include:

  • databricks-claude-3-7-sonnet (the default)

  • ⁠databricks-mixtral-8x7b-instruct⁠

  • ⁠databricks-meta-llama-3-1-70b-instruct⁠

  • ⁠databricks-meta-llama-3-1-405b-instruct⁠

token

An authentication token for the Databricks workspace, or NULL to use ambient credentials.

params

Common model parameters, usually created by params().

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_aws_bedrock(), chat_azure_openai(), chat_cloudflare(), chat_deepseek(), chat_github(), chat_google_gemini(), chat_groq(), chat_huggingface(), chat_mistral(), chat_ollama(), chat_openai(), chat_openai_compatible(), chat_openrouter(), chat_perplexity(), chat_portkey()

Examples

## Not run: 
chat <- chat_databricks()
chat$chat("Tell me three jokes about statisticians")

## End(Not run)

Chat with a model hosted on DeepSeek

Description

Sign up at https://platform.deepseek.com.

Built on top of chat_openai_compatible().

Known limitations

Usage

chat_deepseek(
  system_prompt = NULL,
  base_url = "https://api.deepseek.com",
  api_key = NULL,
  credentials = NULL,
  model = NULL,
  params = NULL,
  api_args = list(),
  echo = NULL,
  api_headers = character()
)

Arguments

system_prompt

A system prompt to set the behavior of the assistant.

base_url

The base URL to the endpoint; the default uses DeepSeek.

api_key

[Deprecated] Use credentials instead.

credentials

Override the default credentials. You generally should not need this argument; instead set the DEEPSEEK_API_KEY environment variable. The best place to set this is in .Renviron, which you can easily edit by calling usethis::edit_r_environ().

If you do need additional control, this argument takes a zero-argument function that returns either a string (the API key), or a named list (added as additional headers to every request).

model

The model to use for the chat (defaults to "deepseek-chat"). We regularly update the default, so we strongly recommend explicitly specifying a model for anything other than casual use.

params

Common model parameters, usually created by params().

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_aws_bedrock(), chat_azure_openai(), chat_cloudflare(), chat_databricks(), chat_github(), chat_google_gemini(), chat_groq(), chat_huggingface(), chat_mistral(), chat_ollama(), chat_openai(), chat_openai_compatible(), chat_openrouter(), chat_perplexity(), chat_portkey()

Examples

## Not run: 
chat <- chat_deepseek()
chat$chat("Tell me three jokes about statisticians")

## End(Not run)

Chat with a model hosted on the GitHub model marketplace

Description

GitHub Models hosts a number of open source and OpenAI models. To access the GitHub model marketplace, you will need to apply for and be accepted into the beta access program. See https://github.com/marketplace/models for details.

This function is a lightweight wrapper around chat_openai() with the defaults tweaked for the GitHub Models marketplace.

GitHub also suports the Azure AI Inference SDK, which you can use by setting base_url to "https://models.inference.ai.azure.com/". This endpoint was used in ellmer v0.3.0 and earlier.

Usage

chat_github(
  system_prompt = NULL,
  base_url = "https://models.github.ai/inference/",
  api_key = NULL,
  credentials = NULL,
  model = NULL,
  params = NULL,
  api_args = list(),
  echo = NULL,
  api_headers = character()
)

models_github(
  base_url = "https://models.github.ai/",
  api_key = NULL,
  credentials = NULL
)

Arguments

system_prompt

A system prompt to set the behavior of the assistant.

base_url

The base URL to the endpoint; the default is OpenAI's public API.

api_key

[Deprecated] Use credentials instead.

credentials

Override the default credentials. You generally should not need this argument; instead set the GITHUB_PAT environment variable. The best place to set this is in .Renviron, which you can easily edit by calling usethis::edit_r_environ().

If you do need additional control, this argument takes a zero-argument function that returns either a string (the API key), or a named list (added as additional headers to every request).

model

The model to use for the chat (defaults to "gpt-4o"). We regularly update the default, so we strongly recommend explicitly specifying a model for anything other than casual use.

params

Common model parameters, usually created by params().

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_aws_bedrock(), chat_azure_openai(), chat_cloudflare(), chat_databricks(), chat_deepseek(), chat_google_gemini(), chat_groq(), chat_huggingface(), chat_mistral(), chat_ollama(), chat_openai(), chat_openai_compatible(), chat_openrouter(), chat_perplexity(), chat_portkey()

Examples

## Not run: 
chat <- chat_github()
chat$chat("Tell me three jokes about statisticians")

## End(Not run)

Chat with a Google Gemini or Vertex AI model

Description

Google's AI offering is broken up into two parts: Gemini and Vertex AI. Most enterprises are likely to use Vertex AI, and individuals are likely to use Gemini.

Use google_upload() to upload files (PDFs, images, video, audio, etc.)

Authentication

These functions try a number of authentication strategies, in this order:

Usage

chat_google_gemini(
  system_prompt = NULL,
  base_url = "https://generativelanguage.googleapis.com/v1beta/",
  api_key = NULL,
  credentials = NULL,
  model = NULL,
  params = NULL,
  api_args = list(),
  api_headers = character(),
  echo = NULL
)

chat_google_vertex(
  location,
  project_id,
  system_prompt = NULL,
  model = NULL,
  params = NULL,
  api_args = list(),
  api_headers = character(),
  echo = NULL
)

models_google_gemini(
  base_url = "https://generativelanguage.googleapis.com/v1beta/",
  api_key = NULL,
  credentials = NULL
)

models_google_vertex(location, project_id, credentials = NULL)

Arguments

system_prompt

A system prompt to set the behavior of the assistant.

base_url

The base URL to the endpoint; the default is OpenAI's public API.

api_key

[Deprecated] Use credentials instead.

credentials

A function that returns a list of authentication headers or NULL, the default, to use ambient credentials. See above for details.

model

The model to use for the chat (defaults to "gemini-2.5-flash"). We regularly update the default, so we strongly recommend explicitly specifying a model for anything other than casual use. Use models_google_gemini() to see all options.

params

Common model parameters, usually created by params().

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

location

Location, e.g. us-east1, me-central1, africa-south1 or global.

project_id

Project ID.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_aws_bedrock(), chat_azure_openai(), chat_cloudflare(), chat_databricks(), chat_deepseek(), chat_github(), chat_groq(), chat_huggingface(), chat_mistral(), chat_ollama(), chat_openai(), chat_openai_compatible(), chat_openrouter(), chat_perplexity(), chat_portkey()

Examples

## Not run: 
chat <- chat_google_gemini()
chat$chat("Tell me three jokes about statisticians")

## End(Not run)

Chat with a model hosted on Groq

Description

Sign up at https://groq.com.

Built on top of chat_openai_compatible().

Known limitations

groq does not currently support structured data extraction.

Usage

chat_groq(
  system_prompt = NULL,
  base_url = "https://api.groq.com/openai/v1",
  api_key = NULL,
  credentials = NULL,
  model = NULL,
  params = NULL,
  api_args = list(),
  echo = NULL,
  api_headers = character()
)

Arguments

system_prompt

A system prompt to set the behavior of the assistant.

base_url

The base URL to the endpoint; the default is OpenAI's public API.

api_key

[Deprecated] Use credentials instead.

credentials

Override the default credentials. You generally should not need this argument; instead set the GROQ_API_KEY environment variable. The best place to set this is in .Renviron, which you can easily edit by calling usethis::edit_r_environ().

If you do need additional control, this argument takes a zero-argument function that returns either a string (the API key), or a named list (added as additional headers to every request).

model

The model to use for the chat (defaults to "llama-3.1-8b-instant"). We regularly update the default, so we strongly recommend explicitly specifying a model for anything other than casual use.

params

Common model parameters, usually created by params().

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_aws_bedrock(), chat_azure_openai(), chat_cloudflare(), chat_databricks(), chat_deepseek(), chat_github(), chat_google_gemini(), chat_huggingface(), chat_mistral(), chat_ollama(), chat_openai(), chat_openai_compatible(), chat_openrouter(), chat_perplexity(), chat_portkey()

Examples

## Not run: 
chat <- chat_groq()
chat$chat("Tell me three jokes about statisticians")

## End(Not run)

Chat with a model hosted on Hugging Face Serverless Inference API

Description

Hugging Face hosts a variety of open-source and proprietary AI models available via their Inference API. To use the Hugging Face API, you must have an Access Token, which you can obtain from your Hugging Face account (ensure that at least "Make calls to Inference Providers" and "Make calls to your Inference Endpoints" is checked).

Built on top of chat_openai_compatible().

Known limitations

Usage

chat_huggingface(
  system_prompt = NULL,
  params = NULL,
  api_key = NULL,
  credentials = NULL,
  model = NULL,
  api_args = list(),
  echo = NULL,
  api_headers = character()
)

Arguments

system_prompt

A system prompt to set the behavior of the assistant.

params

Common model parameters, usually created by params().

api_key

[Deprecated] Use credentials instead.

credentials

Override the default credentials. You generally should not need this argument; instead set the HUGGINGFACE_API_KEY environment variable. The best place to set this is in .Renviron, which you can easily edit by calling usethis::edit_r_environ().

If you do need additional control, this argument takes a zero-argument function that returns either a string (the API key), or a named list (added as additional headers to every request).

model

The model to use for the chat (defaults to "meta-llama/Llama-3.1-8B-Instruct"). We regularly update the default, so we strongly recommend explicitly specifying a model for anything other than casual use.

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_aws_bedrock(), chat_azure_openai(), chat_cloudflare(), chat_databricks(), chat_deepseek(), chat_github(), chat_google_gemini(), chat_groq(), chat_mistral(), chat_ollama(), chat_openai(), chat_openai_compatible(), chat_openrouter(), chat_perplexity(), chat_portkey()

Examples

## Not run: 
chat <- chat_huggingface()
chat$chat("Tell me three jokes about statisticians")

## End(Not run)

Chat with a model hosted on Mistral's La Platforme

Description

Get your API key from https://console.mistral.ai/api-keys.

Built on top of chat_openai_compatible().

Known limitations

Usage

chat_mistral(
  system_prompt = NULL,
  params = NULL,
  api_key = NULL,
  credentials = NULL,
  model = NULL,
  api_args = list(),
  echo = NULL,
  api_headers = character()
)

models_mistral(api_key = mistral_key())

Arguments

system_prompt

A system prompt to set the behavior of the assistant.

params

Common model parameters, usually created by params().

api_key

[Deprecated] Use credentials instead.

credentials

Override the default credentials. You generally should not need this argument; instead set the MISTRAL_API_KEY environment variable. The best place to set this is in .Renviron, which you can easily edit by calling usethis::edit_r_environ().

If you do need additional control, this argument takes a zero-argument function that returns either a string (the API key), or a named list (added as additional headers to every request).

model

The model to use for the chat (defaults to "mistral-large-latest"). We regularly update the default, so we strongly recommend explicitly specifying a model for anything other than casual use.

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_aws_bedrock(), chat_azure_openai(), chat_cloudflare(), chat_databricks(), chat_deepseek(), chat_github(), chat_google_gemini(), chat_groq(), chat_huggingface(), chat_ollama(), chat_openai(), chat_openai_compatible(), chat_openrouter(), chat_perplexity(), chat_portkey()

Examples

## Not run: 
chat <- chat_mistral()
chat$chat("Tell me three jokes about statisticians")

## End(Not run)

Chat with a local Ollama model

Description

To use chat_ollama() first download and install Ollama. Then install some models either from the command line (e.g. with ⁠ollama pull llama3.1⁠) or within R using ollamar (e.g. ollamar::pull("llama3.1")).

Built on top of chat_openai_compatible().

Known limitations

Usage

chat_ollama(
  system_prompt = NULL,
  base_url = Sys.getenv("OLLAMA_BASE_URL", "http://localhost:11434"),
  model,
  params = NULL,
  api_args = list(),
  echo = NULL,
  api_key = NULL,
  credentials = NULL,
  api_headers = character()
)

models_ollama(base_url = "http://localhost:11434", credentials = NULL)

Arguments

system_prompt

A system prompt to set the behavior of the assistant.

base_url

The base URL to the endpoint; the default is OpenAI's public API.

model

The model to use for the chat. Use models_ollama() to see all options.

params

Common model parameters, usually created by params().

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

api_key

[Deprecated] Use credentials instead.

credentials

Ollama doesn't require credentials for local usage and in most cases you do not need to provide credentials.

However, if you're accessing an Ollama instance hosted behind a reverse proxy or secured endpoint that enforces bearer‐token authentication, you can set the OLLAMA_API_KEY environment variable or provide a callback function to credentials.

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_aws_bedrock(), chat_azure_openai(), chat_cloudflare(), chat_databricks(), chat_deepseek(), chat_github(), chat_google_gemini(), chat_groq(), chat_huggingface(), chat_mistral(), chat_openai(), chat_openai_compatible(), chat_openrouter(), chat_perplexity(), chat_portkey()

Examples

## Not run: 
chat <- chat_ollama(model = "llama3.2")
chat$chat("Tell me three jokes about statisticians")

## End(Not run)

Chat with an OpenAI model

Description

This is the main interface to OpenAI's models, using the responses API. You can use this to access OpenAI's latest models and features like image generation and web search. If you need to use an OpenAI-compatible API from another provider, or the chat completions API with OpenAI,use chat_openai_compatible() instead.

Note that a ChatGPT Plus membership does not grant access to the API. You will need to sign up for a developer account (and pay for it) at the developer platform.

Usage

chat_openai(
  system_prompt = NULL,
  base_url = "https://api.openai.com/v1",
  api_key = NULL,
  credentials = NULL,
  model = NULL,
  params = NULL,
  api_args = list(),
  api_headers = character(),
  service_tier = c("auto", "default", "flex", "priority"),
  echo = c("none", "output", "all")
)

models_openai(
  base_url = "https://api.openai.com/v1",
  api_key = NULL,
  credentials = NULL
)

Arguments

system_prompt

A system prompt to set the behavior of the assistant.

base_url

The base URL to the endpoint; the default is OpenAI's public API.

api_key

[Deprecated] Use credentials instead.

credentials

Override the default credentials. You generally should not need this argument; instead set the OPENAI_API_KEY environment variable. The best place to set this is in .Renviron, which you can easily edit by calling usethis::edit_r_environ().

If you do need additional control, this argument takes a zero-argument function that returns either a string (the API key), or a named list (added as additional headers to every request).

model

The model to use for the chat (defaults to "gpt-4.1"). We regularly update the default, so we strongly recommend explicitly specifying a model for anything other than casual use. Use models_openai() to see all options.

params

Common model parameters, usually created by params().

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

service_tier

Request a specific service tier. There are four options:

  • "auto" (default): uses the service tier configured in Project settings.

  • "default": standard pricing and performance.

  • "flex": slower and cheaper.

  • "priority": faster and more expensive.

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_aws_bedrock(), chat_azure_openai(), chat_cloudflare(), chat_databricks(), chat_deepseek(), chat_github(), chat_google_gemini(), chat_groq(), chat_huggingface(), chat_mistral(), chat_ollama(), chat_openai_compatible(), chat_openrouter(), chat_perplexity(), chat_portkey()

Examples


chat <- chat_openai()
chat$chat("
  What is the difference between a tibble and a data frame?
  Answer with a bulleted list
")

chat$chat("Tell me three funny jokes about statisticians")


Chat with an OpenAI-compatible model

Description

This function is for use with OpenAI-compatible APIs, also known as the chat completions API. If you want to use OpenAI itself, we recommend chat_openai(), which uses the newer responses API.

Many providers offer OpenAI-compatible APIs, including:

Usage

chat_openai_compatible(
  base_url,
  name = "OpenAI-compatible",
  system_prompt = NULL,
  api_key = NULL,
  credentials = NULL,
  model = NULL,
  params = NULL,
  api_args = list(),
  api_headers = character(),
  echo = c("none", "output", "all")
)

Arguments

base_url

The base URL to the endpoint. This parameter is required since there is no default for OpenAI-compatible APIs.

name

The name of the provider; this is shown in token_usage() and is used to compute costs.

system_prompt

A system prompt to set the behavior of the assistant.

api_key

[Deprecated] Use credentials instead.

credentials

Credentials to use for authentication. If not provided, will attempt to use the OPENAI_API_KEY environment variable.

model

The model to use for chat. No default; depends on your provider.

params

Common model parameters, usually created by params().

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_aws_bedrock(), chat_azure_openai(), chat_cloudflare(), chat_databricks(), chat_deepseek(), chat_github(), chat_google_gemini(), chat_groq(), chat_huggingface(), chat_mistral(), chat_ollama(), chat_openai(), chat_openrouter(), chat_perplexity(), chat_portkey()

Examples

## Not run: 
# Example with Ollama (requires Ollama running locally)
chat <- chat_openai_compatible(
  base_url = "http://localhost:11434/v1",
  model = "llama2"
)
chat$chat("What is the difference between a tibble and a data frame?")

## End(Not run)

Chat with one of the many models hosted on OpenRouter

Description

Sign up at https://openrouter.ai.

Support for features depends on the underlying model that you use; see https://openrouter.ai/models for details.

Usage

chat_openrouter(
  system_prompt = NULL,
  api_key = NULL,
  credentials = NULL,
  model = NULL,
  params = NULL,
  api_args = list(),
  echo = c("none", "output", "all"),
  api_headers = character()
)

Arguments

system_prompt

A system prompt to set the behavior of the assistant.

api_key

[Deprecated] Use credentials instead.

credentials

Override the default credentials. You generally should not need this argument; instead set the OPENROUTER_API_KEY environment variable. The best place to set this is in .Renviron, which you can easily edit by calling usethis::edit_r_environ().

If you do need additional control, this argument takes a zero-argument function that returns either a string (the API key), or a named list (added as additional headers to every request).

model

The model to use for the chat (defaults to "gpt-4o"). We regularly update the default, so we strongly recommend explicitly specifying a model for anything other than casual use.

params

Common model parameters, usually created by params().

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_aws_bedrock(), chat_azure_openai(), chat_cloudflare(), chat_databricks(), chat_deepseek(), chat_github(), chat_google_gemini(), chat_groq(), chat_huggingface(), chat_mistral(), chat_ollama(), chat_openai(), chat_openai_compatible(), chat_perplexity(), chat_portkey()

Examples

## Not run: 
chat <- chat_openrouter()
chat$chat("Tell me three jokes about statisticians")

## End(Not run)

Chat with a model hosted on perplexity.ai

Description

Sign up at https://www.perplexity.ai.

Perplexity AI is a platform for running LLMs that are capable of searching the web in real-time to help them answer questions with information that may not have been available when the model was trained.

This function is a Uses OpenAI compatible API via chat_openai_compatible() with the defaults tweaked for Perplexity AI.

Usage

chat_perplexity(
  system_prompt = NULL,
  base_url = "https://api.perplexity.ai/",
  api_key = NULL,
  credentials = NULL,
  model = NULL,
  params = NULL,
  api_args = list(),
  echo = NULL,
  api_headers = character()
)

Arguments

system_prompt

A system prompt to set the behavior of the assistant.

base_url

The base URL to the endpoint; the default is OpenAI's public API.

api_key

[Deprecated] Use credentials instead.

credentials

Override the default credentials. You generally should not need this argument; instead set the PERPLEXITY_API_KEY environment variable. The best place to set this is in .Renviron, which you can easily edit by calling usethis::edit_r_environ().

If you do need additional control, this argument takes a zero-argument function that returns either a string (the API key), or a named list (added as additional headers to every request).

model

The model to use for the chat (defaults to "llama-3.1-sonar-small-128k-online"). We regularly update the default, so we strongly recommend explicitly specifying a model for anything other than casual use.

params

Common model parameters, usually created by params().

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_aws_bedrock(), chat_azure_openai(), chat_cloudflare(), chat_databricks(), chat_deepseek(), chat_github(), chat_google_gemini(), chat_groq(), chat_huggingface(), chat_mistral(), chat_ollama(), chat_openai(), chat_openai_compatible(), chat_openrouter(), chat_portkey()

Examples

## Not run: 
chat <- chat_perplexity()
chat$chat("Tell me three jokes about statisticians")

## End(Not run)

Chat with a model hosted on PortkeyAI

Description

PortkeyAI provides an interface (AI Gateway) to connect through its Universal API to a variety of LLMs providers via a single endpoint.

Usage

chat_portkey(
  model,
  system_prompt = NULL,
  base_url = "https://api.portkey.ai/v1",
  api_key = NULL,
  credentials = NULL,
  virtual_key = deprecated(),
  params = NULL,
  api_args = list(),
  echo = NULL,
  api_headers = character()
)

models_portkey(base_url = "https://api.portkey.ai/v1", api_key = portkey_key())

Arguments

model

The model name, e.g. ⁠@my-provider/my-model⁠.

system_prompt

A system prompt to set the behavior of the assistant.

base_url

The base URL to the endpoint; the default is OpenAI's public API.

api_key

[Deprecated] Use credentials instead.

credentials

Override the default credentials. You generally should not need this argument; instead set the PORTKEY_API_KEY environment variable. The best place to set this is in .Renviron, which you can easily edit by calling usethis::edit_r_environ().

If you do need additional control, this argument takes a zero-argument function that returns either a string (the API key), or a named list (added as additional headers to every request).

virtual_key

[Deprecated]. Portkey now recommend supplying the model provider (formerly known as the virtual_key), in the model name, e.g. ⁠@my-provider/my-model⁠. See https://portkey.ai/docs/support/upgrade-to-model-catalog for details.

For backward compatibility, the PORTKEY_VIRTUAL_KEY env var is still used if the model doesn't include a provider.

params

Common model parameters, usually created by params().

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

Value

A Chat object.

See Also

Other chatbots: chat_anthropic(), chat_aws_bedrock(), chat_azure_openai(), chat_cloudflare(), chat_databricks(), chat_deepseek(), chat_github(), chat_google_gemini(), chat_groq(), chat_huggingface(), chat_mistral(), chat_ollama(), chat_openai(), chat_openai_compatible(), chat_openrouter(), chat_perplexity()

Examples

## Not run: 
chat <- chat_portkey()
chat$chat("Tell me three jokes about statisticians")

## End(Not run)

Chat with a model hosted on Snowflake

Description

The Snowflake provider allows you to interact with LLM models available through the Cortex LLM REST API.

Authentication

chat_snowflake() picks up the following ambient Snowflake credentials:

Known limitations

Note that Snowflake-hosted models do not support images.

Usage

chat_snowflake(
  system_prompt = NULL,
  account = snowflake_account(),
  credentials = NULL,
  model = NULL,
  params = NULL,
  api_args = list(),
  echo = c("none", "output", "all"),
  api_headers = character()
)

Arguments

system_prompt

A system prompt to set the behavior of the assistant.

account

A Snowflake account identifier, e.g. "testorg-test_account". Defaults to the value of the SNOWFLAKE_ACCOUNT environment variable.

credentials

A list of authentication headers to pass into httr2::req_headers(), a function that returns them when called, or NULL, the default, to use ambient credentials.

model

The model to use for the chat (defaults to "claude-3-7-sonnet"). We regularly update the default, so we strongly recommend explicitly specifying a model for anything other than casual use.

params

Common model parameters, usually created by params().

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

Value

A Chat object.

Examples


chat <- chat_snowflake()
chat$chat("Tell me a joke in the form of a SQL query.")


Chat with a model hosted by vLLM

Description

vLLM is an open source library that provides an efficient and convenient LLMs model server. You can use chat_vllm() to connect to endpoints powered by vLLM.

Uses OpenAI compatible API via chat_openai_compatible().

Usage

chat_vllm(
  base_url,
  system_prompt = NULL,
  model,
  params = NULL,
  api_args = list(),
  api_key = NULL,
  credentials = NULL,
  echo = NULL,
  api_headers = character()
)

models_vllm(base_url, api_key = NULL, credentials = NULL)

Arguments

base_url

The base URL to the endpoint; the default is OpenAI's public API.

system_prompt

A system prompt to set the behavior of the assistant.

model

The model to use for the chat. Use models_vllm() to see all options.

params

Common model parameters, usually created by params().

api_args

Named list of arbitrary extra arguments appended to the body of every chat API call. Combined with the body object generated by ellmer with modifyList().

api_key

[Deprecated] Use credentials instead.

credentials

Override the default credentials. You generally should not need this argument; instead set the VLLM_API_KEY environment variable. The best place to set this is in .Renviron, which you can easily edit by calling usethis::edit_r_environ().

If you do need additional control, this argument takes a zero-argument function that returns either a string (the API key), or a named list (added as additional headers to every request).

echo

One of the following options:

  • none: don't emit any output (default when running in a function).

  • output: echo text and tool-calling output as it streams in (default when running at the console).

  • all: echo all input and output.

Note this only affects the chat() method.

api_headers

Named character vector of arbitrary extra headers appended to every chat API call.

Value

A Chat object.

Examples

## Not run: 
chat <- chat_vllm("http://my-vllm.com")
chat$chat("Tell me three jokes about statisticians")

## End(Not run)

Upload, downloand, and manage files for Claude

Description

[Experimental] Use the beta Files API to upload files to and manage files in Claude. This is currently experimental because the API is in beta and may change. Note that you need beta-headers = "files-api-2025-04-14" to use the API.

Claude offers 100GB of file storage per organization, with each file having a maximum size of 500MB. For more details see https://docs.claude.com/en/docs/build-with-claude/files

Usage

claude_file_upload(
  path,
  base_url = "https://api.anthropic.com/v1/",
  beta_headers = "files-api-2025-04-14",
  credentials = NULL
)

claude_file_list(
  base_url = "https://api.anthropic.com/v1/",
  credentials = NULL,
  beta_headers = "files-api-2025-04-14"
)

claude_file_get(
  file_id,
  base_url = "https://api.anthropic.com/v1/",
  credentials = NULL,
  beta_headers = "files-api-2025-04-14"
)

claude_file_download(
  file_id,
  path,
  base_url = "https://api.anthropic.com/v1/",
  credentials = NULL,
  beta_headers = "files-api-2025-04-14"
)

claude_file_delete(
  file_id,
  base_url = "https://api.anthropic.com/v1/",
  credentials = NULL,
  beta_headers = "files-api-2025-04-14"
)

Arguments

path

Path to download the file to.

base_url

The base URL to the endpoint; the default is Claude's public API.

beta_headers

Beta headers to use for the request. Defaults to files-api-2025-04-14.

credentials

Override the default credentials. You generally should not need this argument; instead set the ANTHROPIC_API_KEY environment variable. The best place to set this is in .Renviron, which you can easily edit by calling usethis::edit_r_environ().

If you do need additional control, this argument takes a zero-argument function that returns either a string (the API key), or a named list (added as additional headers to every request).

file_id

ID of the file to get information about, download, or delete.

Examples

## Not run: 
file <- claude_file_upload("path/to/file.pdf")
chat <- chat_anthropic(beta_headers = "files-api-2025-04-14")
chat$chat("Please summarize the document.", file)

## End(Not run)

Claude web fetch tool

Description

Enables Claude to fetch and analyze content from web URLs. Claude can only fetch URLs that appear in the conversation context (user messages or previous tool results). For security reasons, Claude cannot dynamically construct URLs to fetch.

Requires the web-fetch-2025-09-10 beta header. Learn more in https://docs.claude.com/en/docs/agents-and-tools/tool-use/web-fetch-tool.

Usage

claude_tool_web_fetch(
  max_uses = NULL,
  allowed_domains = NULL,
  blocked_domains = NULL,
  citations = FALSE,
  max_content_tokens = NULL
)

Arguments

max_uses

Integer. Maximum number of fetches allowed per request.

allowed_domains

Character vector. Restrict fetches to specific domains. Cannot be used with blocked_domains.

blocked_domains

Character vector. Exclude specific domains from fetches. Cannot be used with allowed_domains.

citations

Logical. Whether to include citations in the response. Default is TRUE.

max_content_tokens

Integer. Maximum number of tokens to fetch from each URL.

See Also

Other built-in tools: claude_tool_web_search(), google_tool_web_fetch(), google_tool_web_search(), openai_tool_web_search()

Examples

## Not run: 
chat <- chat_claude(beta_headers = "web-fetch-2025-09-10")
chat$register_tool(claude_tool_web_fetch())
chat$chat("What are the latest package releases on https://tidyverse.org/blog")

## End(Not run)

Description

Enables Claude to search the web for up-to-date information. Your organization administrator must enable web search in the Anthropic Console before using this tool, as it costs extra ($10 per 1,000 tokens at time of writing).

Learn more in https://docs.claude.com/en/docs/agents-and-tools/tool-use/web-search-tool.

Usage

claude_tool_web_search(
  max_uses = NULL,
  allowed_domains = NULL,
  blocked_domains = NULL,
  user_location = NULL
)

Arguments

max_uses

Integer. Maximum number of searches allowed per request.

allowed_domains

Character vector. Restrict searches to specific domains (e.g., c("nytimes.com", "bbc.com")). Cannot be used with blocked_domains.

blocked_domains

Character vector. Exclude specific domains from searches. Cannot be used with allowed_domains.

user_location

List with optional elements: country (2-letter code), city, region, and timezone (IANA timezone) to localize search results.

See Also

Other built-in tools: claude_tool_web_fetch(), google_tool_web_fetch(), google_tool_web_search(), openai_tool_web_search()

Examples

## Not run: 
chat <- chat_claude()
chat$register_tool(claude_tool_web_search())
chat$chat("What was in the news today?")
chat$chat("What's the biggest news in the economy?")

## End(Not run)

Encode images for chat input

Description

These functions are used to prepare image URLs and files for input to the chatbot. The content_image_url() function is used to provide a URL to an image, while content_image_file() is used to provide the image data itself.

Usage

content_image_url(url, detail = c("auto", "low", "high"))

content_image_file(path, content_type = "auto", resize = "low")

content_image_plot(width = 768, height = 768)

Arguments

url

The URL of the image to include in the chat input. Can be a ⁠data:⁠ URL or a regular URL. Valid image types are PNG, JPEG, WebP, and non-animated GIF.

detail

The detail setting for this image. Can be "auto", "low", or "high".

path

The path to the image file to include in the chat input. Valid file extensions are .png, .jpeg, .jpg, .webp, and (non-animated) .gif.

content_type

The content type of the image (e.g. image/png). If "auto", the content type is inferred from the file extension.

resize

If "low", resize images to fit within 512x512. If "high", resize to fit within 2000x768 or 768x2000. (See the OpenAI docs for more on why these specific sizes are used.) If "none", do not resize.

You can also pass a custom string to resize the image to a specific size, e.g. "200x200" to resize to 200x200 pixels while preserving aspect ratio. Append > to resize only if the image is larger than the specified size, and ! to ignore aspect ratio (e.g. "300x200>!").

All values other than none require the magick package.

width, height

Width and height in pixels.

Value

An input object suitable for including in the ... parameter of the chat(), stream(), chat_async(), or stream_async() methods.

Examples

## Not run: 
chat <- chat_openai()
chat$chat(
  "What do you see in these images?",
  content_image_url("https://www.r-project.org/Rlogo.png"),
  content_image_file(system.file("httr2.png", package = "ellmer"))
)

plot(waiting ~ eruptions, data = faithful)
chat <- chat_openai()
chat$chat(
  "Describe this plot in one paragraph, as suitable for inclusion in
   alt-text. You should briefly describe the plot type, the axes, and
   2-5 major visual patterns.",
   content_image_plot()
)

## End(Not run)

Encode PDFs content for chat input

Description

These functions are used to prepare PDFs as input to the chatbot. The content_pdf_url() function is used to provide a URL to an PDF file, while content_pdf_file() is used to for local PDF files.

Not all providers support PDF input, so check the documentation for the provider you are using.

Usage

content_pdf_file(path)

content_pdf_url(url)

Arguments

path, url

Path or URL to a PDF file.

Value

A ContentPDF object


Record and replay content

Description

These generic functions can be use to convert Turn/Content objects into easily serializable representations (i.e. lists and atomic vectors).

Usage

contents_record(x)

contents_replay(x, tools = list(), .envir = parent.frame())

Arguments

x

A Turn or Content object to serialize; or a serialized object to replay.

tools

A named list of tools

.envir

The environment in which to look for class definitions. Used when the recorded objects include classes that extend Turn or Content but are not from the ellmer package itself.


Format contents into a textual representation

Description

[Experimental]

These generic functions can be use to convert Turn contents or Content objects into textual representations.

These content types will continue to grow and change as ellmer evolves to support more providers and as providers add more content types.

Usage

contents_text(content, ...)

contents_html(content, ...)

contents_markdown(content, ...)

Arguments

content

The Turn or Content object to be converted into text. contents_markdown() also accepts Chat instances to turn the entire conversation history into markdown text.

...

Additional arguments passed to methods.

Value

A string of text, markdown or HTML.

Examples

turns <- list(
  UserTurn(list(
    ContentText("What's this image?"),
    content_image_url("https://placehold.co/200x200")
  )),
  AssistantTurn("It's a placeholder image.")
)

lapply(turns, contents_text)
lapply(turns, contents_markdown)
if (rlang::is_installed("commonmark")) {
  contents_html(turns[[1]])
}


Create metadata for a tool

Description

In order to use a function as a tool in a chat, you need to craft the right call to tool(). This function helps you do that for documented functions by extracting the function's R documentation and using an LLM to generate the tool() call. It's meant to be used interactively while writing your code, not as part of your final code.

If the function has package documentation, that will be used. Otherwise, if the source code of the function can be automatically detected, then the comments immediately preceding the function are used (especially helpful if those are roxygen2 comments). If neither are available, then just the function signature is used.

Note that this function is inherently imperfect. It can't handle all possible R functions, because not all parameters are suitable for use in a tool call (for example, because they're not serializable to simple JSON objects). The documentation might not specify the expected shape of arguments to the level of detail that would allow an exact JSON schema to be generated. Please be sure to review the generated code before using it!

Usage

create_tool_def(topic, chat = NULL, echo = interactive(), verbose = FALSE)

Arguments

topic

A symbol or string literal naming the function to create metadata for. Can also be an expression of the form pkg::fun.

chat

A Chat object used to generate the output. If NULL (the default) uses chat_openai().

echo

Emit the registration code to the console. Defaults to TRUE in interactive sessions.

verbose

If TRUE, print the input we send to the LLM, which may be useful for debugging unexpectedly poor results.

Value

A register_tool call that you can copy and paste into your code. Returned invisibly if echo is TRUE.

Examples

## Not run: 
  # These are all equivalent
  create_tool_def(rnorm)
  create_tool_def(stats::rnorm)
  create_tool_def("rnorm")
  create_tool_def("rnorm", chat = chat_azure_openai())

## End(Not run)


Describe the schema of a data frame, suitable for sending to an LLM

Description

df_schema() gives a column-by-column description of a data frame. For each column, it gives the name, type, label (if present), and number of missing values. For numeric and date/time columns, it also gives the range. For character and factor columns, it also gives the number of unique values, and if there's only a few (<= 10), their values.

The goal is to give the LLM a sense of the structure of the data, so that it can generate useful code, and the output attempts to balance between conciseness and accuracy.

Usage

df_schema(df, max_cols = 50)

Arguments

df

A data frame to describe.

max_cols

Maximum number of columns to includes. Defaults to 50 to avoid accidentally generating very large prompts.

Examples

df_schema(mtcars)
df_schema(iris)

Google URL fetch tool

Description

When this tool is enabled, you can include URLs directly in your prompts and Gemini will fetch and analyze the content.

Learn more in https://ai.google.dev/gemini-api/docs/url-context.

Usage

google_tool_web_fetch()

See Also

Other built-in tools: claude_tool_web_fetch(), claude_tool_web_search(), google_tool_web_search(), openai_tool_web_search()

Examples

## Not run: 
chat <- chat_google_gemini()
chat$register_tool(google_tool_web_fetch())
chat$chat("What are the latest package releases on https://tidyverse.org/blog?")

## End(Not run)

Description

Enables Gemini models to search the web for up-to-date information and ground responses with citations to sources. The model automatically decides when (and how) to search the web based on your prompt. Search results are incorporated into the response with grounding metadata including source URLs and titles.

Learn more in https://ai.google.dev/gemini-api/docs/google-search.

Usage

google_tool_web_search()

See Also

Other built-in tools: claude_tool_web_fetch(), claude_tool_web_search(), google_tool_web_fetch(), openai_tool_web_search()

Examples

## Not run: 
chat <- chat_google_gemini()
chat$register_tool(google_tool_web_search())
chat$chat("What was in the news today?")
chat$chat("What's the biggest news in the economy?")

## End(Not run)

Upload a file to gemini

Description

[Experimental]

This function uploads a file then waits for Gemini to finish processing it so that you can immediately use it in a prompt. It's experimental because it's currently Gemini specific, and we expect other providers to evolve similar feature in the future.

Uploaded files are automatically deleted after 2 days. Each file must be less than 2 GB and you can upload a total of 20 GB. ellmer doesn't currently provide a way to delete files early; please file an issue if this would be useful for you.

Usage

google_upload(
  path,
  base_url = "https://generativelanguage.googleapis.com/",
  api_key = NULL,
  credentials = NULL,
  mime_type = NULL
)

Arguments

path

Path to a file to upload.

base_url

The base URL to the endpoint; the default is OpenAI's public API.

api_key

[Deprecated] Use credentials instead.

credentials

A function that returns a list of authentication headers or NULL, the default, to use ambient credentials. See above for details.

mime_type

Optionally, specify the mime type of the file. If not specified, will be guesses from the file extension.

Value

A ⁠<ContentUploaded>⁠ object that can be passed to ⁠$chat()⁠.

Examples

## Not run: 
file <- google_upload("path/to/file.pdf")

chat <- chat_google_gemini()
chat$chat(file, "Give me a three paragraph summary of this PDF")

## End(Not run)

Are credentials avaiable?

Description

Used for examples/testing.

Usage

has_credentials(provider)

Arguments

provider

Provider name.


Helpers for interpolating data into prompts

Description

These functions are lightweight wrappers around glue that make it easier to interpolate dynamic data into a static prompt:

Compared to glue, dynamic values should be wrapped in {{ }}, making it easier to include R code and JSON in your prompt.

Usage

interpolate(prompt, ..., .envir = parent.frame())

interpolate_file(path, ..., .envir = parent.frame())

interpolate_package(package, path, ..., .envir = parent.frame())

Arguments

prompt

A prompt string. You should not generally expose this to the end user, since glue interpolation makes it easy to run arbitrary code.

...

Define additional temporary variables for substitution.

.envir

Environment to evaluate ... expressions in. Used when wrapping in another function. See vignette("wrappers", package = "glue") for more details.

path

A path to a prompt file (often a .md). In interpolate_package(), this path is relative to inst/prompts.

package

Package name.

Value

A {glue} string.

Examples

joke <- "You're a cool dude who loves to make jokes. Tell me a joke about {{topic}}."

# You can supply valuese directly:
interpolate(joke, topic = "bananas")

# Or allow interpolate to find them in the current environment:
topic <- "applies"
interpolate(joke)



Open a live chat application

Description

Note that these functions will mutate the input chat object as you chat because your turns will be appended to the history.

Usage

live_console(chat, quiet = FALSE)

live_browser(chat, quiet = FALSE)

Arguments

chat

A chat object created by chat_openai() or friends.

quiet

If TRUE, suppresses the initial message that explains how to use the console.

Value

(Invisibly) The input chat.

Examples

## Not run: 
chat <- chat_anthropic()
live_console(chat)
live_browser(chat)

## End(Not run)

Description

Enables OpenAI models to search the web for up-to-date information. The search behavior varies by model: non-reasoning models perform simple searches, while reasoning models can perform agentic, iterative searches.

Learn more at https://platform.openai.com/docs/guides/tools-web-search

Usage

openai_tool_web_search(
  allowed_domains = NULL,
  user_location = NULL,
  external_web_access = TRUE
)

Arguments

allowed_domains

Character vector. Restrict searches to specific domains (e.g., c("nytimes.com", "bbc.com")). Maximum 20 domains. URLs will be automatically cleaned (http/https prefixes removed).

user_location

List with optional elements: country (2-letter ISO code), city, region, and timezone (IANA timezone) to localize search results.

external_web_access

Logical. Whether to allow live internet access (TRUE, default) or use only cached/indexed results (FALSE).

See Also

Other built-in tools: claude_tool_web_fetch(), claude_tool_web_search(), google_tool_web_fetch(), google_tool_web_search()

Examples

## Not run: 
chat <- chat_openai()
chat$register_tool(openai_tool_web_search())
chat$chat("Very briefly summarise the top 3 news stories of the day")
chat$chat("Of those stories, which one do you think was the most interesting?")

## End(Not run)

Submit multiple chats in parallel

Description

If you have multiple prompts, you can submit them in parallel. This is typically considerably faster than submitting them in sequence, especially with Gemini and OpenAI.

If you're using chat_openai() or chat_anthropic() and you're willing to wait longer, you might want to use batch_chat() instead, as it comes with a 50% discount in return for taking up to 24 hours.

Usage

parallel_chat(
  chat,
  prompts,
  max_active = 10,
  rpm = 500,
  on_error = c("return", "continue", "stop")
)

parallel_chat_text(
  chat,
  prompts,
  max_active = 10,
  rpm = 500,
  on_error = c("return", "continue", "stop")
)

parallel_chat_structured(
  chat,
  prompts,
  type,
  convert = TRUE,
  include_tokens = FALSE,
  include_cost = FALSE,
  max_active = 10,
  rpm = 500,
  on_error = c("return", "continue", "stop")
)

Arguments

chat

A chat object created by a chat_ function, or a string passed to chat().

prompts

A vector created by interpolate() or a list of character vectors.

max_active

The maximum number of simultaneous requests to send.

For chat_anthropic(), note that the number of active connections is limited primarily by the output tokens per minute limit (OTPM) which is estimated from the max_tokens parameter, which defaults to 4096. That means if your usage tier limits you to 16,000 OTPM, you should either set max_active = 4 (16,000 / 4096) to decrease the number of active connections or use params() in chat_anthropic() to decrease max_tokens.

rpm

Maximum number of requests per minute.

on_error

What to do when a request fails. One of:

  • "return" (the default): stop processing new requests, wait for in flight requests to finish, then return.

  • "continue": keep going, performing every request.

  • "stop": stop processing and throw an error.

type

A type specification for the extracted data. Should be created with a type_() function.

convert

If TRUE, automatically convert from JSON lists to R data types using the schema. This typically works best when type is type_object() as this will give you a data frame with one column for each property. If FALSE, returns a list.

include_tokens

If TRUE, and the result is a data frame, will add input_tokens and output_tokens columns giving the total input and output tokens for each prompt.

include_cost

If TRUE, and the result is a data frame, will add cost column giving the cost of each prompt.

Value

For parallel_chat(), a list with one element for each prompt. Each element is either a Chat object (if successful), a NULL (if the request wasn't performed) or an error object (if it failed).

For parallel_chat_text(), a character vector with one element for each prompt. Requests that weren't succesful get an NA.

For parallel_chat_structured(), a single structured data object with one element for each prompt. Typically, when type is an object, this will be a tibble with one row for each prompt, and one column for each property. If the output is a data frame, and some requests error, an .error column will be added with the error objects.

Examples


chat <- chat_openai()

# Chat ----------------------------------------------------------------------
country <- c("Canada", "New Zealand", "Jamaica", "United States")
prompts <- interpolate("What's the capital of {{country}}?")
parallel_chat(chat, prompts)

# Structured data -----------------------------------------------------------
prompts <- list(
  "I go by Alex. 42 years on this planet and counting.",
  "Pleased to meet you! I'm Jamal, age 27.",
  "They call me Li Wei. Nineteen years young.",
  "Fatima here. Just celebrated my 35th birthday last week.",
  "The name's Robert - 51 years old and proud of it.",
  "Kwame here - just hit the big 5-0 this year."
)
type_person <- type_object(name = type_string(), age = type_number())
parallel_chat_structured(chat, prompts, type_person)


Standard model parameters

Description

This helper function makes it easier to create a list of parameters used across many models. The parameter names are automatically standardised and included in the correctly place in the API call.

Note that parameters that are not supported by a given provider will generate a warning, not an error. This allows you to use the same set of parameters across multiple providers.

Usage

params(
  temperature = NULL,
  top_p = NULL,
  top_k = NULL,
  frequency_penalty = NULL,
  presence_penalty = NULL,
  seed = NULL,
  max_tokens = NULL,
  log_probs = NULL,
  stop_sequences = NULL,
  reasoning_effort = NULL,
  reasoning_tokens = NULL,
  ...
)

Arguments

temperature

Temperature of the sampling distribution.

top_p

The cumulative probability for token selection.

top_k

The number of highest probability vocabulary tokens to keep.

frequency_penalty

Frequency penalty for generated tokens.

presence_penalty

Presence penalty for generated tokens.

seed

Seed for random number generator.

max_tokens

Maximum number of tokens to generate.

log_probs

Include the log probabilities in the output?

stop_sequences

A character vector of tokens to stop generation on.

reasoning_effort, reasoning_tokens

How much effort to spend thinking? ressoning_effort is a string, like "low", "medium", "high". reasoning_tokens is an integer, giving a maximum token budget. Each provider only takes one of these two parameters.

...

Additional named parameters to send to the provider.


Report on token usage in the current session

Description

Call this function to find out the cumulative number of tokens that you have sent and recieved in the current session. The price will be shown if known.

Usage

token_usage()

Value

A data frame

Examples

token_usage()

Define a tool

Description

Annotate a function for use in tool calls, by providing a name, description, and type definition for the arguments.

Learn more in vignette("tool-calling").

Usage

tool(
  fun,
  description,
  ...,
  arguments = list(),
  name = NULL,
  convert = TRUE,
  annotations = list(),
  .name = deprecated(),
  .description = deprecated(),
  .convert = deprecated(),
  .annotations = deprecated()
)

Arguments

fun

The function to be invoked when the tool is called. The return value of the function is sent back to the chatbot.

Expert users can customize the tool result by returning a ContentToolResult object.

description

A detailed description of what the function does. Generally, the more information that you can provide here, the better.

...

[Deprecated] Use arguments instead.

arguments

A named list that defines the arguments accepted by the function. Each element should be created by a type_*() function. Use type_ignore() if you don't want the LLM to provide that argument (e.g., because the R function has a suitable default value).

name

The name of the function. This can be omitted if fun is an existing function (i.e. not defined inline).

convert

Should JSON inputs be automatically convert to their R data type equivalents? Defaults to TRUE.

annotations

Additional properties that describe the tool and its behavior. Usually created by tool_annotations(), where you can find a description of the annotation properties recommended by the Model Context Protocol.

.name, .description, .convert, .annotations

[Deprecated] Please switch to the non-prefixed equivalents.

Value

An S7 ToolDef object.

ellmer 0.3.0

In ellmer 0.3.0, the definition of the tool() function changed quite a bit. To make it easier to update old versions, you can use an LLM with the following system prompt

Help the user convert an ellmer 0.2.0 and earlier tool definition into a
ellmer 0.3.0 tool definition. Here's what changed:

* All arguments, apart from the first, should be named, and the argument
  names no longer use `.` prefixes. The argument order should be function,
  name (as a string), description, then arguments, then anything

* Previously `arguments` was passed as `...`, so all type specifications
  should now be moved into a named list and passed to the `arguments`
  argument. It can be omitted if the function has no arguments.

```R
# old
tool(
  add,
  "Add two numbers together"
  x = type_number(),
  y = type_number()
)

# new
tool(
  add,
  name = "add",
  description = "Add two numbers together",
  arguments = list(
    x = type_number(),
    y = type_number()
  )
)
```

Don't respond; just let the user provide function calls to convert.

See Also

Other tool calling helpers: tool_annotations(), tool_reject()

Examples



# First define the metadata that the model uses to figure out when to
# call the tool
tool_rnorm <- tool(
  rnorm,
  description = "Draw numbers from a random normal distribution",
  arguments = list(
    n = type_integer("The number of observations. Must be a positive integer."),
    mean = type_number("The mean value of the distribution."),
    sd = type_number("The standard deviation of the distribution. Must be a non-negative number.")
  )
)
tool_rnorm(n = 5, mean = 0, sd = 1)

chat <- chat_openai()
# Then register it
chat$register_tool(tool_rnorm)

# Then ask a question that needs it.
chat$chat("Give me five numbers from a random normal distribution.")

# Look at the chat history to see how tool calling works:
chat
# Assistant sends a tool request which is evaluated locally and
# results are sent back in a tool result.



Tool annotations

Description

Tool annotations are additional properties that, when passed to the .annotations argument of tool(), provide additional information about the tool and its behavior. This information can be used for display to users, for example in a Shiny app or another user interface.

The annotations in tool_annotations() are drawn from the Model Context Protocol and are considered hints. Tool authors should use these annotations to communicate tool properties, but users should note that these annotations are not guaranteed.

Usage

tool_annotations(
  title = NULL,
  read_only_hint = NULL,
  open_world_hint = NULL,
  idempotent_hint = NULL,
  destructive_hint = NULL,
  ...
)

Arguments

title

A human-readable title for the tool.

read_only_hint

If TRUE, the tool does not modify its environment.

open_world_hint

If TRUE, the tool may interact with an "open world" of external entities. If FALSE, the tool's domain of interaction is closed. For example, the world of a web search tool is open, but the world of a memory tool is not.

idempotent_hint

If TRUE, calling the tool repeatedly with the same arguments will have no additional effect on its environment. (Only meaningful when read_only_hint is FALSE.)

destructive_hint

If TRUE, the tool may perform destructive updates to its environment, otherwise it only performs additive updates. (Only meaningful when read_only_hint is FALSE.)

...

Additional named parameters to include in the tool annotations.

Value

A list of tool annotations.

See Also

Other tool calling helpers: tool(), tool_reject()

Examples

# See ?tool() for a full example using this function.
# We're creating a tool around R's `rnorm()` function to allow the chatbot to
# generate random numbers from a normal distribution.
tool_rnorm <- tool(
  rnorm,
  # Describe the tool function to the LLM
  .description = "Drawn numbers from a random normal distribution",
  # Describe the parameters used by the tool function
  n = type_integer("The number of observations. Must be a positive integer."),
  mean = type_number("The mean value of the distribution."),
  sd = type_number("The standard deviation of the distribution. Must be a non-negative number."),
  # Tool annotations optionally provide additional context to the LLM
  .annotations = tool_annotations(
    title = "Draw Random Normal Numbers",
    read_only_hint = TRUE, # the tool does not modify any state
    open_world_hint = FALSE # the tool does not interact with the outside world
  )
)


Reject a tool call

Description

Throws an error to reject a tool call. tool_reject() can be used within the tool function to indicate that the tool call should not be processed. tool_reject() can also be called in an Chat$on_tool_request() callback. When used in the callback, the tool call is rejected before the tool function is invoked.

Here's an example where utils::askYesNo() is used to ask the user for permission before accessing their current working directory. This happens directly in the tool function and is appropriate when you write the tool definition and know exactly how it will be called.

chat <- chat_openai(model = "gpt-4.1-nano")

list_files <- function() {
  allow_read <- utils::askYesNo(
    "Would you like to allow access to your current directory?"
  )
  if (isTRUE(allow_read)) {
    dir(pattern = "[.](r|R|csv)$")
  } else {
    tool_reject()
  }
}

chat$register_tool(tool(
  list_files,
  "List files in the user's current directory"
))

chat$chat("What files are available in my current directory?")
#> [tool call] list_files()
#> Would you like to allow access to your current directory? (Yes/no/cancel) no
#> #> Error: Tool call rejected. The user has chosen to disallow the tool #' call.
#> It seems I am unable to access the files in your current directory right now.
#> If you can tell me what specific files you're looking for or if you can #' provide
#> the list, I can assist you further.

chat$chat("Try again.")
#> [tool call] list_files()
#> Would you like to allow access to your current directory? (Yes/no/cancel) yes
#> #> app.R
#> #> data.csv
#> The files available in your current directory are "app.R" and "data.csv".

You can achieve a similar experience with tools written by others by using a tool_request callback. In the next example, imagine the tool is provided by a third-party package. This example implements a simple menu to ask the user for consent before running any tool.

packaged_list_files_tool <- tool(
  function() dir(pattern = "[.](r|R|csv)$"),
  "List files in the user's current directory"
)

chat <- chat_openai(model = "gpt-4.1-nano")
chat$register_tool(packaged_list_files_tool)

always_allowed <- c()

# ContentToolRequest
chat$on_tool_request(function(request) {
  if (request@name %in% always_allowed) return()

  answer <- utils::menu(
    title = sprintf("Allow tool `%s()` to run?", request@name),
    choices = c("Always", "Once", "No"),
    graphics = FALSE
  )

  if (answer == 1) {
    always_allowed <<- append(always_allowed, request@name)
  } else if (answer %in% c(0, 3)) {
    tool_reject()
  }
})

# Try choosing different answers to the menu each time
chat$chat("What files are available in my current directory?")
chat$chat("How about now?")
chat$chat("And again now?")

Usage

tool_reject(reason = "The user has chosen to disallow the tool call.")

Arguments

reason

A character string describing the reason for rejecting the tool call.

Value

Throws an error of class ellmer_tool_reject with the provided reason.

See Also

Other tool calling helpers: tool(), tool_annotations()


Type specifications

Description

These functions specify object types in a way that chatbots understand and are used for tool calling and structured data extraction. Their names are based on the JSON schema, which is what the APIs expect behind the scenes. The translation from R concepts to these types is fairly straightforward.

Usage

type_boolean(description = NULL, required = TRUE)

type_integer(description = NULL, required = TRUE)

type_number(description = NULL, required = TRUE)

type_string(description = NULL, required = TRUE)

type_enum(values, description = NULL, required = TRUE)

type_array(items, description = NULL, required = TRUE)

type_object(
  .description = NULL,
  ...,
  .required = TRUE,
  .additional_properties = FALSE
)

type_from_schema(text, path)

type_ignore()

Arguments

description, .description

The purpose of the component. This is used by the LLM to determine what values to pass to the tool or what values to extract in the structured data, so the more detail that you can provide here, the better.

required, .required

Is the component or argument required?

In type descriptions for structured data, if required = FALSE and the component does not exist in the data, the LLM may hallucinate a value. Only applies when the element is nested inside of a type_object().

In tool definitions, required = TRUE signals that the LLM should always provide a value. Arguments with required = FALSE should have a default value in the tool function's definition. If the LLM does not provide a value, the default value will be used.

values

Character vector of permitted values.

items

The type of the array items. Can be created by any of the type_ function.

...

<dynamic-dots> Name-type pairs defining the components that the object must possess.

.additional_properties

Can the object have arbitrary additional properties that are not explicitly listed? Only supported by Claude.

text

A JSON string.

path

A file path to a JSON file.

Examples

# An integer vector
type_array(type_integer())

# The closest equivalent to a data frame is an array of objects
type_array(type_object(
   x = type_boolean(),
   y = type_string(),
   z = type_number()
))

# There's no specific type for dates, but you use a string with the
# requested format in the description (it's not gauranteed that you'll
# get this format back, but you should most of the time)
type_string("The creation date, in YYYY-MM-DD format.")
type_string("The update date, in dd/mm/yyyy format.")