get_file

Instructions

Implementation Reference

• src/index.ts:336-423 (handler)

  The core handler function implementing the 'get_file' tool. It maps the repository name to a GitHub repository and branch, constructs the raw file URL, fetches the content, and returns it in MCP format. Handles fetch errors gracefully.

  private async getFile(repo: string, path: string) {
    try {
      // All Firefox repos now use the unified repository
      const firefoxGithubRepo = "mozilla/firefox";
  
      // Map Searchfox repo names to GitHub branches
      const branchMapping: Record<string, string> = {
        "mozilla-central": "main",
        autoland: "autoland",
        "mozilla-beta": "beta",
        "mozilla-release": "release",
        "mozilla-esr115": "esr115",
        "mozilla-esr128": "esr128",
        "mozilla-esr140": "esr140",
        // comm-central is still in mercurial, but there is an experimental
        // repository in https://github.com/mozilla/releases-comm-central/
        "comm-central": "main",
      };
  
      const branch = branchMapping[repo] || "main";
  
      // comm-central is still in mercurial, but there is an experimental
      // repository in https://github.com/mozilla/releases-comm-central/
      const repoToUse =
        repo === "comm-central"
          ? "mozilla/releases-comm-central"
          : firefoxGithubRepo;
  
      // Construct GitHub raw URL
      const githubRawUrl = `https://raw.githubusercontent.com/${repoToUse}/${branch}/${path}`;
  
      try {
        // Try to fetch from GitHub
        const response = await fetch(githubRawUrl);
  
        if (!response.ok) {
          throw new Error(`HTTP ${response.status}: ${response.statusText}`);
        }
  
        const content = await response.text();
  
        return {
          content: [
            {
              type: "text",
              text: JSON.stringify(
                {
                  repo,
                  path,
                  content: content,
                  source: "github",
                  url: githubRawUrl,
                  searchfoxUrl: `${this.baseUrl}/${repo}/source/${path}`,
                },
                null,
                2
              ),
            },
          ],
        };
      } catch (githubError) {
        console.error("GitHub fetch failed.", githubError);
  
        return {
          content: [
            {
              type: "text",
              text: JSON.stringify(
                {
                  repo,
                  path,
                  content: "",
                  note: "Error: GitHub fetch failed",
                },
                null,
                2
              ),
            },
          ],
        };
      }
    } catch (error) {
      throw new McpError(
        ErrorCode.InternalError,
        `Failed to fetch file: ${error instanceof Error ? error.message : String(error)}`
      );
    }
  }

• src/index.ts:124-143 (registration)

  Tool registration in the ListTools response. Defines the tool name, description, and input schema (repo optional, path required).

  {
    name: "get_file",
    description:
      "Get the contents of a specific file from specified repository.",
    inputSchema: {
      type: "object",
      properties: {
        repo: {
          type: "string",
          description: "Repository name",
          default: "mozilla-central",
        },
        path: {
          type: "string",
          description: "File path within the repository",
        },
      },
      required: ["path"],
    },
  },

• src/index.ts:128-142 (schema)

  Input schema definition for the 'get_file' tool, specifying object with optional repo (default mozilla-central) and required path.

  inputSchema: {
    type: "object",
    properties: {
      repo: {
        type: "string",
        description: "Repository name",
        default: "mozilla-central",
      },
      path: {
        type: "string",
        description: "File path within the repository",
      },
    },
    required: ["path"],
  },

• src/index.ts:184-198 (handler)

  Dispatcher handler in CallToolRequestSchema that validates arguments and delegates to the getFile implementation.

  case "get_file": {
    const fileArgs = args as Record<string, unknown>;
    if (!fileArgs.path || typeof fileArgs.path !== "string") {
      throw new McpError(
        ErrorCode.InvalidParams,
        "Path parameter is required and must be a string"
      );
    }
  
    const repo =
      typeof fileArgs.repo === "string"
        ? fileArgs.repo
        : "mozilla-central";
    return await this.getFile(repo, fileArgs.path);
  }