get_asr_task

Instructions

Implementation Reference

• src/index.js:172-188 (schema)

  Schema definition for the 'get_asr_task' tool. Declares the tool name, description, annotations (using ANN.ASR_POLL), and inputSchema with a required 'task_id' string parameter. This tells the MCP client what parameters the tool accepts.

  {
    name: "get_asr_task",
    description:
      "Poll the status of an ASR task created by transcribe_video. Returns one of `queued`, `downloading`, `transcribing`, `finalizing`, `done`, or `failed`. When status is `done`, includes the full transcript with timestamps. Recommended polling interval: 3-5 seconds. Free — does not consume credits.",
    annotations: { title: "Get ASR Task Status", ...ANN.ASR_POLL },
    inputSchema: {
      type: "object",
      properties: {
        task_id: {
          type: "string",
          description: "Task ID returned by transcribe_video.",
          minLength: 1,
        },
      },
      required: ["task_id"],
    },
  },

• src/index.js:443-448 (registration)

  Registration of all tools (including get_asr_task) in the MCP server via the TOOLS array. The ListToolsRequestSchema handler returns the TOOLS array containing the get_asr_task schema definition.

  const server = new Server(
    { name: "subdownload", version: "1.0.0" },
    { capabilities: { tools: {} } }
  );
  
  server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: TOOLS }));

• src/index.js:450-462 (handler)

  Handler for tool calls. The CallToolRequestSchema handler forwards any tool call (including 'get_asr_task') to the upstream SubDownload API via callUpstream, passing the tool name and arguments as-is. There is no local implementation — this is a proxy that delegates to https://api.subdownload.com/mcp.

  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 executes the actual logic. It sends a JSON-RPC tools/call request with the tool name and arguments to the upstream SubDownload MCP endpoint, authenticating with the Bearer token from SUBDOWNLOAD_API_KEY.

  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;
  }

• src/index.js:49-55 (helper)

  Annotation hints (ANN.ASR_POLL) used by get_asr_task. Marks the tool as readOnlyHint=true (safe to call), idempotentHint=false (status changes over time), and openWorldHint=false (hits own backend only).

  // ASR poll — hits our backend only, status changes over time
  ASR_POLL: {
    readOnlyHint: true,
    destructiveHint: false,
    idempotentHint: false,
    openWorldHint: false,
  },