search_channel_videos

Instructions

Implementation Reference

• src/index.js:245-271 (registration)

  The tool 'search_channel_videos' is registered in the TOOLS array (line 246) with its name, description, annotations, and inputSchema. It requires 'channel' and 'q' parameters, with an optional 'limit' (1-50). The actual handler logic is delegated via the generic callUpstream() proxy to the upstream SubDownload API.

  {
    name: "search_channel_videos",
    description:
      "Search for specific videos within a single YouTube channel. Restricts results to the given channel. Use after resolve_channel if starting from a handle. Useful for 'find Karpathy's video about backpropagation' style queries.",
    annotations: { title: "Search Channel Videos", ...ANN.YT_READ },
    inputSchema: {
      type: "object",
      properties: {
        channel: {
          type: "string",
          description: "@handle, channel URL, or UC... channel ID.",
          minLength: 1,
        },
        q: {
          type: "string",
          description: "Search query (matched against video title and description within the channel).",
          minLength: 1,
        },
        limit: {
          type: "number",
          description: "Max results (1-50, default 30).",
          minimum: 1,
          maximum: 50,
        },
      },
      required: ["channel", "q"],
    },

• src/index.js:450-462 (handler)

  Generic CallToolRequestSchema handler: all tools (including search_channel_videos) are forwarded to the upstream MCP server via callUpstream(), which sends a JSON-RPC tools/call request to the SubDownload API.

  server.setRequestHandler(CallToolRequestSchema, async (request) => {
    try {
      return await callUpstream(
        request.params.name,
        request.params.arguments || {}
      );
    } catch (err) {
      return {
        content: [{ type: "text", text: err.message || String(err) }],
        isError: true,
      };
    }
  });

• src/index.js:408-441 (helper)

  The callUpstream() helper function that proxies all tool calls (including search_channel_videos) to the upstream SubDownload MCP endpoint with the Bearer token.

  async function callUpstream(name, args) {
    if (!API_KEY) {
      throw new Error(
        "SUBDOWNLOAD_API_KEY env var is not set. Get one at https://subdownload.com/account, then run with -e SUBDOWNLOAD_API_KEY=<your-key>."
      );
    }
    const res = await fetch(UPSTREAM_URL, {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        Accept: "application/json, text/event-stream",
        Authorization: `Bearer ${API_KEY}`,
      },
      body: JSON.stringify({
        jsonrpc: "2.0",
        id: Date.now(),
        method: "tools/call",
        params: { name, arguments: args },
      }),
    });
    const text = await res.text();
    let body;
    try {
      body = JSON.parse(text);
    } catch {
      throw new Error(
        `Upstream returned non-JSON response (HTTP ${res.status}): ${text.slice(0, 200)}`
      );
    }
    if (body.error) {
      throw new Error(body.error.message || JSON.stringify(body.error));
    }
    return body.result;
  }