spawn

# /hub:spawn — Launch Parallel Agents Spawn N subagents that work on the same task in parallel, each in an isolated git worktree. ## Usage ``` /hub:spawn # Spawn agents for the latest session /hub:spawn 20260317-143022 # Spawn agents for a specific session /hub:spawn --template optimizer # Use optimizer template for dispatch prompts /hub:spawn --template refactorer # Use refactorer template ``` ## Templates When `--template <name>` is provided, use the dispatch prompt from `references/agent-templates.md` instead of the default prompt below. Available templates: | Template | Pattern | Use Case | |----------|---------|----------| | `optimizer` | Edit → eval → keep/discard → repeat x10 | Performance, latency, size reduction | | `refactorer` | Restructure → test → iterate until green | Code quality, tech debt | | `test-writer` | Write tests → measure coverage → repeat | Test coverage gaps | | `bug-fixer` | Reproduce → diagnose → fix → verify | Bug fix with competing approaches | When using a template, replace all `{variables}` with values from the session config. Assign each agent a **different strategy** appropriate to the template and task — diverse strategies maximize the value of parallel exploration. ## What It Does 1. Load session config from `.agenthub/sessions/{session-id}/config.yaml` 2. For each agent 1..N: - Write task assignment to `.agenthub/board/dispatch/` - Build agent prompt with task, constraints, and board write instructions 3. Launch ALL agents in a **single message** with multiple Agent tool calls: ``` Agent( prompt: "You are agent-{i} in hub session {session-id}. Your task: {task} Read your full assignment at .agenthub/board/dispatch/{seq}-agent-{i}.md Instructions: 1. Work in your worktree — make changes, run tests, iterate 2. Commit all changes with descriptive messages 3. Write your result summary to .agenthub/board/results/agent-{i}-result.md Include: approach taken, files changed, metric if available, confidence level 4. Exit when done Constraints: - Do NOT read or modify other agents' work - Do NOT access .agenthub/board/results/ for other agents - Commit early and often with descriptive messages - If you hit a dead end, commit what you have and explain in your result", isolation: "worktree" ) ``` 4. Update session state to `running` via: ```bash python {skill_path}/scripts/session_manager.py --update {session-id} --state running ``` ## Critical Rules - **All agents in ONE message** — spawn all Agent tool calls simultaneously for true parallelism - **isolation: "worktree"** is mandatory — each agent needs its own filesystem - **Never modify session config** after spawn — agents rely on stable configuration - **Each agent gets a unique board post** — dispatch posts are numbered sequentially ## After Spawn Tell the user: - {N} agents launched in parallel - Each working in an isolated worktree - Monitor with `/hub:status` - Evaluate when done with `/hub:eval` --- ## Why This Skill Exists Implement — Launch N parallel subagents in isolated git worktrees to compete on the session task. <!-- SR_40: auto-generated from frontmatter `purpose`/`description` (OPP-Phase3). Expand with domain-specific rationale. --> ## When to Use Use this skill when the task requires spawn capabilities. <!-- SR_40: auto-generated from frontmatter `when`/`description` (OPP-Phase3). --> ## What If Fails If this skill fails to produce the expected output: (1) verify input completeness, (2) retry with more specific context, (3) fall back to the parent workflow without this skill. <!-- SR_40: auto-generated from frontmatter `what_if_fails` (OPP-Phase3). -->