Agents spawning agents

An agent connected to Solo MCP can launch another agent in the same project. For example, Claude Code can ask Codex to review a change.

The agents can use different tools and providers. Each CLI keeps its own permissions, provider account, and usage limits.

Run Claude Code and Codex together#

Use Claude Code to make a change and Codex to review it. You need both CLIs installed and signed in. Solo launches the tools you install.

1. In Settings > Agents, check that both tools are enabled and available. See Setting up agent tools.
2. Launch Claude Code in your repository's project.
3. Connect Claude Code to Solo MCP.
4. Give Claude Code a small change and the command that verifies it.
5. Ask Claude Code to launch Codex for a read-only review after the checks pass.

You can paste this into the lead session:

Implement the bug fix we agreed on and run the relevant checks.
Use Solo MCP to list available agent tools and launch Codex in this project.
Ask Codex to review the diff without editing files. Give it the intended
behavior and check results. Ask for findings with file locations.
Check each finding against the code before applying a fix.
Do not commit or push.

Without MCP, launch Codex yourself in the same project and give it the review prompt.

Keep Codex read-only while Claude Code edits the files. If both agents need to edit, assign different files or use linked checkouts. Agents in the same directory can overwrite each other's changes.

Read the reviewer's output before treating the review as complete. An idle status only tells you that the agent is waiting.

Add a queue file watcher with a reviewer#

Use a Laravel development project with a Queue command running php artisan queue:work and auto_restart: true. See Run a Laravel dev stack for the setup.

File-watch restarts can interrupt jobs. Use a development queue you can interrupt. For jobs that must finish first, use Laravel's graceful restart.

Ask the writer to add file-watch restarts for job changes:

Inspect solo.yml and use Solo MCP to inspect Queue in this project.
Add app/Jobs/**/*.php to Queue's restart_when_changed list if it is missing.
Change only that list. Preserve the other settings and commands.
Ask Codex to review the diff without editing files. Have it check the pattern,
confirm that other settings are unchanged, and verify that the YAML parses.
Show the diff and review findings.
Do not sync the configuration, restart processes, commit, or push.

With the default Laravel job directory, the Queue definition looks like this:

processes:
  Queue:
    command: php artisan queue:work
    auto_start: false
    auto_restart: true
    restart_when_changed:
      - app/Jobs/**/*.php

If your jobs live elsewhere, use that path in the pattern.

After the review, test the change:

1. Accept Solo's configuration sync prompt.
2. Restart Queue to activate the new watch pattern.
3. Add a comment to an existing PHP job under app/Jobs and save it.
4. Inspect the Queue output and confirm that the worker restarts.
5. Remove your test comment without reverting other edits.

Claude Code and Codex keep running. The command's restart settings apply only to Queue.

Delegate other tasks#

Give the lead agent a specific task for each worker:

• Implement a change in named files.
• Review a diff without editing files.
• Update documentation for a completed change.

Include the files the worker may edit, the expected result, and the verification command in its prompt. Workers have separate conversations, so include the context they need.

The lead can spawn workers, inspect their output, and set timers to check progress. See Agent orchestration workflow for coordination with todos and scratchpads.

Requirements#

• The target agent tool must be configured and enabled in Solo.
• The target tool must have a launchable installation for the effective project environment. Ready and unknown-health tools can be launched; missing or broken installations cannot.
• The lead agent must have access to Solo MCP tools.
• The spawned agent runs in the effective Solo project scope.
• Configure models, permissions, and CLI flags in the agent tool settings or per-launch extra_args. Solo delivers the initial prompt after launch, so the prompt cannot set launch flags. Later changes depend on the agent CLI.