chat_github: Chat with a model hosted on the GitHub model marketplace

In ellmer: Chat with Large Language Models

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.

The defaults are tweaked for the GitHub Models marketplace.

GitHub also supports 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 API endpoint.
api_key	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-5"). 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_lmstudio(), chat_mistral(), chat_ollama(), chat_openai(), chat_openai_compatible(), chat_openrouter(), chat_perplexity(), chat_portkey(), chat_posit()

Examples

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

## End(Not run)

ellmer documentation built on July 14, 2026, 1:07 a.m.