| prompt | The prompt for the model | no | "" |
| prompt-file | Path to a file containing the prompt (supports .txt and .prompt.yml formats) | no | "" |
| input | Template variables in YAML format for .prompt.yml files | no | "" |
| file_input | Template variables in YAML format mapping variable names to file paths. The file contents will be used for templating. | no | "" |
| model | The model to use | no | openai/gpt-4o |
| endpoint | The endpoint to use | no | https://models.github.ai/inference |
| system-prompt | The system prompt for the model | no | You are a helpful assistant |
| system-prompt-file | Path to a file containing the system prompt | no | "" |
| max-tokens | The maximum number of tokens to generate (deprecated) | no | 200 |
| max-completion-tokens | The maximum number of tokens to generate | no | "" |
| temperature | The sampling temperature to use (0-1) | no | "" |
| top-p | The nucleus sampling parameter to use (0-1) | no | "" |
| token | The token to use | no | ${{ github.token }} |
| enable-github-mcp | Enable Model Context Protocol integration with GitHub tools | no | false |
| github-mcp-token | The token to use for GitHub MCP server (defaults to the main token if not specified). This must be a PAT for MCP to work. | no | "" |
| github-mcp-toolsets | Comma-separated list of toolsets to enable for GitHub MCP (e.g., "repos,issues,pull_requests,actions"). Use "all" for all toolsets, "default" for default set. If not specified, uses default toolsets (context,repos,issues,pull_requests,users). | no | "" |
| custom-headers | Custom HTTP headers to include in API requests. Supports both YAML format (header1: value1) and JSON format ({"header1": "value1"}). Useful for API Management platforms, rate limiting, and request tracking. | no | "" |
| provider | Inference provider to use. "github-models" (default) calls the GitHub Models REST API. "copilot" shells out to the GitHub Copilot CLI, which must be installed and authenticated on the runner before this action runs (see README for an example workflow). | no | github-models |
| copilot-cli-path | Path to the Copilot CLI binary (only used when provider is "copilot"). Defaults to "copilot" on PATH. | no | "" |
| copilot-allow-tools | Comma-separated list of tools to allow when provider is "copilot" (passed through as --allow-tool). Example: "shell(git:*),write". | no | "" |