spawn

A command for starting a separate coding-agent session in a registered project, using its own Git worktree. A worktree is an additional working copy of a repository, so changes stay separated.

In plain words
What is it for?
Starting a named worker with a chosen agent, branch, project, and initial instruction. It is useful for splitting development work into isolated sessions.
Why use it?
It lets agents work on different tasks without changing the same files or branch at the same time. You can also connect a session to an issue or existing pull request.

Command

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/tinhtran24/maestro/spawn
Clone the repo
git clone --depth 1 https://github.com/tinhtran24/maestro
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 447 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 95% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00447
Opus 5 $0.00000 $0.00224
Sonnet 5 $0.00000 $0.00089
Haiku 4.5 $0.00000 $0.00045

Measured 2d ago against content hash 21acd2d4ca09, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

spawn scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

95% identical to spawn — 14 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

backend/internal/skillassets/using-maestro/commands/spawn.md · 39 lines

What it actually says

to spawn

Spawn a worker agent session in a registered project. The session runs the chosen agent in a fresh git worktree. Register the project first with maestro project add.

Syntax

maestro spawn [flags]

Flags

Flag Meaning Default / Required
--branch string Branch for the session worktree maestro/<session-id>/root
--claim-pr string Immediately claim an existing PR for the spawned session -
--harness string Agent harness to use (see list below) Project worker.agent; required if the project has none
--issue string Issue id to associate with the session -
--name string Display name shown in the sidebar (max 20 characters) Required
--no-takeover Refuse if another active session owns the claimed PR (requires --claim-pr) -
--project string Project id to spawn the session in Required
--prompt string Initial prompt for the agent -

--agent is an alias for --harness.

Available harnesses: claude-code, codex, aider, opencode, grok, droid, amp, agy, crush, cursor, qwen, copilot, goose, auggie, continue, devin, cline, kimi, kiro, kilocode, vibe, pi, autohand.

Examples

# Spawn a worker for issue 142 in the maestro project
maestro spawn --project maestro --issue 142 --name "fix-session-leak" --prompt "Fix the session leak described in issue 142. Branch off upstream/main."
# Spawn a worker and immediately claim an open PR
maestro spawn --project maestro --name "review-pr-88" --claim-pr 88 --harness claude-code
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 39 lines · 0 tokens per session scan A 21acd2d4ca09

Subscribe to this mod's changes

spawn is a command published in the GitHub repository tinhtran24/maestro (3 stars, last pushed 1mo ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 447 tokens. A static security scan graded it A with 0 findings. It is 95% identical to spawn, differing in 14 lines, and is treated as a copy.