codex_reply

Instructions

Implementation Reference

• src/tools/query.ts:176-199 (registration)

  The tool "[toolName]_reply" (e.g., codex_reply) is dynamically registered in `registerQueryTools`. It uses `runQuery` to continue a thread.

  if (baseConfig.persistSession !== false) {
    server.registerTool(replyToolName, {
      description: [
        `Continue a previous ${toolName} conversation by thread ID.`,
        "Use this for follow-up questions, iterative refinement,",
        "or multi-step workflows that build on prior context.",
      ].join(" "),
      inputSchema: z.object({
        thread_id: z.string().describe(`Thread ID from a prior ${toolName} response`),
        prompt: z.string().describe("Follow-up instruction or question"),
        cwd: z.string().optional().describe("Working directory override"),
        model: z.string().optional().describe("Model override"),
      }),
    }, async ({ thread_id, prompt, cwd, model }) => {
      try {
        const result = await runQuery(prompt, {
          cwd, model, resumeThreadId: thread_id,
        }, baseConfig, apiKey);
        return formatResult(result);
      } catch (error) {
        return formatError(error);
      }
    });
  }

• src/tools/query.ts:19-116 (handler)

  The `runQuery` function handles the execution for both initial queries and reply/follow-up calls by checking `overrides.resumeThreadId`.

  async function runQuery(
    prompt: string,
    overrides: InvocationOverrides,
    baseConfig: ThreadConfig,
    apiKey?: string
  ): Promise<RunResult> {
    const codex = new Codex({
      ...(apiKey ? { apiKey } : {}),
    });
  
    const threadOptions: Record<string, unknown> = {};
  
    // Model
    const model = overrides.model || baseConfig.model;
    if (model) threadOptions.model = model;
  
    // Working directory — accept any path, preserve agent's base access
    let cwd = baseConfig.cwd || process.cwd();
    if (overrides.cwd) {
      const resolvedCwd = resolve(cwd, overrides.cwd);
      if (resolvedCwd !== cwd) {
        const dirs = new Set(baseConfig.additionalDirectories || []);
        dirs.add(cwd);
        threadOptions.additionalDirectories = [...dirs];
        cwd = resolvedCwd;
      }
    }
    threadOptions.workingDirectory = cwd;
  
    // Per-invocation additionalDirs — unions with server-level + auto-added dirs
    if (overrides.additionalDirs?.length) {
      const existing = (threadOptions.additionalDirectories as string[]) || baseConfig.additionalDirectories || [];
      const dirs = new Set(existing);
      for (const dir of overrides.additionalDirs) {
        dirs.add(dir);
      }
      threadOptions.additionalDirectories = [...dirs];
    } else if (baseConfig.additionalDirectories && !threadOptions.additionalDirectories) {
      threadOptions.additionalDirectories = baseConfig.additionalDirectories;
    }
  
    // Sandbox mode — can only tighten
    const baseSandbox = baseConfig.sandboxMode || "read-only";
    if (overrides.sandboxMode) {
      threadOptions.sandboxMode = narrowSandboxMode(baseSandbox, overrides.sandboxMode);
    } else {
      threadOptions.sandboxMode = baseSandbox;
    }
  
    // Approval policy — can only tighten
    const baseApproval = baseConfig.approvalPolicy || "on-failure";
    if (overrides.approvalPolicy) {
      threadOptions.approvalPolicy = narrowApprovalPolicy(baseApproval, overrides.approvalPolicy);
    } else {
      threadOptions.approvalPolicy = baseApproval;
    }
  
    // Effort
    const effort = overrides.effort || baseConfig.effort;
    if (effort) threadOptions.modelReasoningEffort = effort;
  
    // Network access
    if (overrides.networkAccess !== undefined) {
      threadOptions.networkAccessEnabled = overrides.networkAccess;
    } else if (baseConfig.networkAccess !== undefined) {
      threadOptions.networkAccessEnabled = baseConfig.networkAccess;
    }
  
    // Web search
    const webSearch = overrides.webSearchMode || baseConfig.webSearchMode;
    if (webSearch) threadOptions.webSearchMode = webSearch;
  
    // Start or resume thread
    const thread = overrides.resumeThreadId
      ? codex.resumeThread(overrides.resumeThreadId, threadOptions)
      : codex.startThread(threadOptions);
  
    // Build prompt with instructions
    let fullPrompt = prompt;
    if (!overrides.resumeThreadId) {
      const instructions = overrides.instructions || baseConfig.instructions;
      const appendInstructions = baseConfig.appendInstructions;
      if (instructions) {
        fullPrompt = `${instructions}\n\n${prompt}`;
      } else if (appendInstructions) {
        fullPrompt = `${appendInstructions}\n\n${prompt}`;
      }
    }
  
    const turn = await thread.run(fullPrompt);
  
    return {
      threadId: thread.id || "",
      response: turn.finalResponse || "",
      usage: turn.usage || { input_tokens: 0, cached_input_tokens: 0, output_tokens: 0 },
      isError: false,
    };
  }