GitHub Action Trigger MCP Server

Instructions

Implementation Reference

• src/index.ts:603-660 (handler)

  The core handler function that fetches the specified action.yml file from a GitHub repository using the GitHub API, decodes and parses the YAML content using js-yaml, extracts and formats the inputs and other metadata, and returns a structured representation of the GitHub Action.
  async function getGitHubAction(owner: string, repo: string, path: string = 'action.yml', ref: string = 'main', token?: string) { // Use provided token or fall back to config token const authToken = token || config.githubToken; try { const headers: Record<string, string> = { 'Accept': 'application/vnd.github+json', 'X-GitHub-Api-Version': '2022-11-28' }; if (authToken) { headers['Authorization'] = `Bearer ${authToken}`; } // First, try to get the action.yml file content const contentResponse = await axios.get( `https://api.github.com/repos/${owner}/${repo}/contents/${path}?ref=${ref}`, { headers } ); if (!contentResponse.data.content) { throw new Error(`Could not find ${path} file in ${owner}/${repo}`); } // Decode the base64 content const content = Buffer.from(contentResponse.data.content, 'base64').toString('utf-8'); // Parse the YAML content const yaml = require('js-yaml'); const actionDefinition = yaml.load(content); // Extract and format the inputs information const inputs = actionDefinition.inputs || {}; const formattedInputs = Object.entries(inputs).map(([name, config]: [string, any]) => ({ name, description: config.description || '', default: config.default, required: config.required === true, deprecationMessage: config.deprecationMessage, })); return { name: actionDefinition.name || '', description: actionDefinition.description || '', author: actionDefinition.author || '', inputs: formattedInputs, runs: actionDefinition.runs, branding: actionDefinition.branding, // Include original content for reference originalYaml: content }; } catch (error) { if (axios.isAxiosError(error)) { throw new Error(`GitHub API error: ${error.response?.status} ${error.response?.statusText} - ${error.response?.data?.message || error.message}`); } throw error; } }
• src/index.ts:131-159 (registration)

  Registers the 'get_github_action' tool in the MCP server's listTools response, including its name, description, and input schema definition.
  name: "get_github_action", description: "Get detailed information about a specific GitHub Action, including inputs and their requirements", inputSchema: { type: "object", properties: { owner: { type: "string", description: "Owner of the action (username or organization)" }, repo: { type: "string", description: "Repository name of the action" }, path: { type: "string", description: "Path to the action.yml or action.yaml file (usually just 'action.yml')" }, ref: { type: "string", description: "Git reference (branch, tag, or commit SHA, default: main)" }, token: { type: "string", description: "GitHub personal access token (optional)" } }, required: ["owner", "repo"] } },
• src/index.ts:133-158 (schema)

  Defines the input schema for the 'get_github_action' tool, specifying properties like owner, repo, path, ref, token, with owner and repo required.
  inputSchema: { type: "object", properties: { owner: { type: "string", description: "Owner of the action (username or organization)" }, repo: { type: "string", description: "Repository name of the action" }, path: { type: "string", description: "Path to the action.yml or action.yaml file (usually just 'action.yml')" }, ref: { type: "string", description: "Git reference (branch, tag, or commit SHA, default: main)" }, token: { type: "string", description: "GitHub personal access token (optional)" } }, required: ["owner", "repo"] }
• src/index.ts:754-780 (handler)

  The MCP CallToolRequestHandler case that handles incoming calls to 'get_github_action', extracts arguments, validates inputs, calls the getGitHubAction function, and returns the result as MCP content.
  case "get_github_action": { const owner = String(request.params.arguments?.owner); const repo = String(request.params.arguments?.repo); const path = request.params.arguments?.path ? String(request.params.arguments?.path) : 'action.yml'; const ref = request.params.arguments?.ref ? String(request.params.arguments?.ref) : 'main'; const token = request.params.arguments?.token ? String(request.params.arguments?.token) : undefined; if (!owner || !repo) { throw new Error("Owner and repo are required"); } try { const actionDetails = await getGitHubAction(owner, repo, path, ref, token); return { content: [{ type: "text", text: JSON.stringify(actionDetails, null, 2) }] }; } catch (error) { if (error instanceof Error) { throw new Error(`Failed to get GitHub Action details: ${error.message}`); } throw error; } }