mavis_session_new

Instructions

Implementation Reference

• src/index.js:142-159 (registration)

  Tool registration entry in the tools array. Defines name, description, inputSchema (zod validation), and buildArgs for the mavis_session_new tool.

  {
    name: 'mavis_session_new',
    description: 'Create a new standalone Mavis session (use --from root for isolated, independent session). For child sessions linked to a parent, use mavis_spawn_worker instead.',
    inputSchema: z.object({
      agent: z.string().describe('Agent name (e.g. mavis, coder, general, verifier)'),
      prompt: z.string().optional().describe('Initial prompt to send to the new session'),
      title: z.string().optional().describe('Optional session title'),
      workspace: z.string().optional().describe('Session workspace directory path'),
      model: z.string().optional().describe('Override LLM model (providerID/modelID format)')
    }),
    buildArgs: ({ agent, prompt, title, workspace, model }) => {
      const args = ['session', 'new', agent, '--from', 'root', '--prompt', prompt || 'hello'];
      if (title) args.push('--title', title);
      if (workspace) args.push('--workspace', workspace);
      if (model) args.push('--model', model);
      return args;
    }
  },

• src/index.js:145-151 (schema)

  Input validation schema using zod for mavis_session_new. Validates: agent (required string), prompt (optional string), title (optional string), workspace (optional string), model (optional string).

  inputSchema: z.object({
    agent: z.string().describe('Agent name (e.g. mavis, coder, general, verifier)'),
    prompt: z.string().optional().describe('Initial prompt to send to the new session'),
    title: z.string().optional().describe('Optional session title'),
    workspace: z.string().optional().describe('Session workspace directory path'),
    model: z.string().optional().describe('Override LLM model (providerID/modelID format)')
  }),

• src/index.js:152-158 (handler)

  buildArgs function that constructs CLI arguments for the Mavis CLI binary. Calls `session new <agent> --from root --prompt <prompt>` with optional --title, --workspace, --model flags. Default prompt is 'hello'.

  buildArgs: ({ agent, prompt, title, workspace, model }) => {
    const args = ['session', 'new', agent, '--from', 'root', '--prompt', prompt || 'hello'];
    if (title) args.push('--title', title);
    if (workspace) args.push('--workspace', workspace);
    if (model) args.push('--model', model);
    return args;
  }

• src/index.js:77-92 (helper)

  runTool function — the generic handler runner that uses buildArgs from the tool spec, calls execMavis or execMavisJSON, formats output as text or raw.

  function runTool(spec, parsedArgs) {
    const { execFn, outputMode, stdin, buildArgs } = spec;
    const args = buildArgs(parsedArgs);
    const input = typeof stdin === 'function' ? stdin(parsedArgs) : stdin;
  
    const execPromise = execFn
      ? execMavis(args, input || '')
      : execMavisJSON(args);
  
    return execPromise.then(result => {
      const text = outputMode === OUTPUT_RAW
        ? (result || '')
        : JSON.stringify(result, null, 2);
      return [{ type: 'text', text }];
    });
  }

• src/index.js:32-53 (helper)

  execMavis helper — spawns the Mavis CLI binary with given args, optionally injecting parent session ID via --session flag.

  function execMavis(args, input = '') {
    return new Promise((resolve, reject) => {
      const SESSION_COMMANDS = new Set(['communication', 'session', 'spawn']);
      const sessionId = process.env.__MAVIS_PARENT_SESSION_ID;
      const subcmd = args[0];
      const needsSession = SESSION_COMMANDS.has(subcmd) && sessionId;
      const finalArgs = needsSession ? [...args, '--session', sessionId] : args;
      const proc = spawn(MAVIS_BIN, finalArgs, { stdio: ['pipe', 'pipe', 'pipe'] });
      let stdout = '';
      let stderr = '';
  
      proc.stdout.on('data', d => stdout += d.toString());
      proc.stderr.on('data', d => stderr += d.toString());
      proc.on('close', code => {
        if (code === 0) resolve(stdout.trim());
        else reject(new Error(stderr.split('\n')[0] || `exit code ${code}`));
      });
      proc.on('error', reject);
  
      if (input) proc.stdin.write(input), proc.stdin.end();
    });
  }