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Enables an Openclaw agent to spawn sub-agents (child Openclaw instances) when a task is too large, complex, or parallel to handle alone. Use this skill whene...

Openclaw Spawner

Allows an Openclaw agent to spawn child Openclaw agents, passing them exactly the context they need to carry out their piece of work and report results back.

Helper script: scripts/spawn_openclaw.py — copy this into your project and import from it. It contains spawn_openclaw(), spawn_openclaw_async(), is_error(), and read_result().

Multi-provider: Uses LiteLLM — pass any supported model string via the model= argument. Default is "anthropic/claude-opus-4-6".

Requires: litellm Python package (pip install litellm) and the API key env var for your chosen provider (e.g. ANTHROPIC_API_KEY, OPENAI_API_KEY, GEMINI_API_KEY).

Tool format: OpenAI function-call format. LiteLLM translates to each provider's native format automatically.

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Security Notes

Credential: spawn_openclaw.py uses LiteLLM to call your chosen provider. Set the matching API key env var (e.g. ANTHROPIC_API_KEY, OPENAI_API_KEY). Never put keys in a payload or snapshot.

Tool format: Tools must be in OpenAI function-call format. LiteLLM translates them to each provider's native format automatically.

Filesystem access: Passing tools= to a child agent grants that child whatever capabilities those tools carry. File-access tools allow children to read and write arbitrary paths. Only supply tools you would trust the parent to use directly. When in doubt, omit tools= — the child will return results in its summary text.

Snapshot sanitization: progress_so_far is sent to the Anthropic API and injected into the child's context. Before spawning, review snapshots and strip any secrets, credentials, personal data, or other sensitive information.

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When to Spawn

Spawn a child agent when any of these are true:

• The remaining task has a clearly separable sub-task that can run independently.
• Two or more subtasks can proceed in parallel, saving wall-clock time.
• The current agent's context window is approaching its limit and a fresh context would help.
• A sub-task requires different tools, permissions, or specialization.
• The user explicitly asks to spawn / delegate / parallelize.

Do not spawn for trivial one-step tasks; keep it in the current agent.

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Spawn Depth Limit

MAX_DEPTH = 3 (configurable in scripts/spawn_openclaw.py).

Depth	Role
0	Root / parent agent
1	Direct child (default spawn)
2	Grandchild (only if child's sub_task explicitly permits spawning)
3+	Blocked — raises ValueError

Always pass depth=<current_depth + 1> when calling spawn_openclaw() from inside a child.

---

Spawn Payload Schema

Every spawn call must include these three fields:

{
  "main_task_title": "<short human-readable title of the overall parent task>",
  "progress_so_far": "<markdown summary of what has already been done, decisions made, artefacts produced, and anything the sub-agent must know to avoid redoing work>",
  "sub_task": "<clear, self-contained description of exactly what this child agent must do, including expected output format and where/how to return results>"
}

Field Guidelines

Field	Rules
main_task_title	≤ 10 words. Stable across all children of the same parent.
progress_so_far	Include: steps completed, key decisions, files written, variables/state the child needs. Exclude: raw data the child doesn't need. Keep it dense but readable.
sub_task	Must be self-contained. Assume the child has zero memory of the parent conversation. Include: what to do, inputs, expected output format, where to put results (file path, return value, etc.).

---

Step-by-Step Spawning Protocol

1 — Decide to Spawn

Confirm the sub-task is genuinely separable. If in doubt, handle it yourself.

2 — Freeze Parent State

Before spawning, write a progress snapshot. This becomes progress_so_far for the child and serves as the parent's own checkpoint in case it needs to resume.

Sanitize before spawning. progress_so_far is sent to the Anthropic API and injected into the child's context. Remove any secrets, API keys, passwords, tokens, or personal data before including them in the snapshot.

## Progress Snapshot — <main_task_title>
**Completed:**
- <step 1>
- <step 2>

**Artifacts produced:**
- <file or output name>: <one-line description>

**Decisions made:**
- <decision>: <rationale>

**Pending (what the child will handle):**
- <sub-task description>

3 — Build the Spawn Payload

Fill in the three required fields from the snapshot above.

4 — Spawn the Openclaw Sub-Instance

Import from scripts/spawn_openclaw.py:

Important: Without tools=, the child is a pure language model — it can reason and produce text but cannot read or write files. If the sub_task requires file I/O, pass the appropriate tool definitions (e.g. Anthropic computer-use tools, custom file tools). When tools are omitted, collect the child's result from the summary string directly rather than calling read_result().

from spawn_openclaw import spawn_openclaw, is_error, read_result

# my_tools = [...]  # OpenAI function-call format tools if the child needs file I/O

payload = {
    "main_task_title": "Refactor authentication module",
    "progress_so_far": (
        "## Progress Snapshot\n"
        "**Completed:**\n- Audited existing auth flow\n- Identified 3 outdated JWT helpers\n\n"
        "**Artifacts produced:**\n- `/tmp/audit_report.md`: full list of issues\n\n"
        "**Decisions made:**\n- Use PyJWT 2.x API; drop legacy HS256 fallback\n\n"
        "**Pending (child handles):**\n- Rewrite auth/jwt_helpers.py per audit report"
    ),
    "sub_task": (
        "Rewrite `/src/auth/jwt_helpers.py` using PyJWT 2.x. "
        "Read `/tmp/audit_report.md` for issues to fix. "
        "Write the rewritten file to `/tmp/jwt_helpers_new.py` and a "
        "one-paragraph summary to `/tmp/jwt_helpers_changes.md`."
    ),
}

try:
    # Swap model= to use any LiteLLM-supported provider:
    # "openai/gpt-4o", "gemini/gemini-2.0-flash", "groq/llama-3.3-70b-versatile", etc.
    summary = spawn_openclaw(payload, depth=1, model="anthropic/claude-opus-4-6", tools=my_tools)
except (ValueError, FileNotFoundError) as exc:
    raise  # bad depth, missing payload key, or SKILL.md not found — fix the call

if is_error(summary):
    print("Child failed:", summary)
else:
    result = read_result("/tmp/jwt_helpers_changes.md")
    if result is None:
        print("WARNING: child did not write expected result file.")

If SKILL.md is not adjacent to spawn_openclaw.py, pass the path explicitly:

import pathlib
summary = spawn_openclaw(payload, depth=1, skill_path=pathlib.Path("/your/path/to/SKILL.md"))

5 — Await and Integrate Results

1. Check is_error(summary) — handle failures before reading files.
2. Use read_result(path) to safely read child output; treat None as child failure.
3. Merge into parent progress snapshot.
4. Continue with the next step of the parent task — or spawn another child if needed.

---

Spawning Strategies

Strategy	When to use	Parent blocks?
Sequential	Child output is needed for next parent step	Yes, until child done
Parallel-gather	Multiple independent children; parent needs all before continuing	Yes, until all done
Fire-and-forget	Child works on a separable track; parent has its own work now	No — merge later

---

Strategy A — Sequential

Use spawn_openclaw(payload, depth=1) as shown in Step 4. Read result, check for errors, continue.

---

Strategy B — Parallel Gather

import asyncio
from spawn_openclaw import spawn_openclaw_async, is_error, read_result

async def main():
    payloads = [
        {
            "main_task_title": "Generate market research report",
            "progress_so_far": "Outline approved. Three sections assigned in parallel.",
            "sub_task": "Write 'Competitive Landscape' (600 words). Save to /tmp/section_competitive.md."
        },
        {
            "main_task_title": "Generate market research report",
            "progress_so_far": "Outline approved. Three sections assigned in parallel.",
            "sub_task": "Write 'Customer Segments' (600 words). Save to /tmp/section_customers.md."
        },
        {
            "main_task_title": "Generate market research report",
            "progress_so_far": "Outline approved. Three sections assigned in parallel.",
            "sub_task": "Write 'Market Trends' (600 words). Save to /tmp/section_trends.md."
        },
    ]

    summaries = await asyncio.gather(
        *[spawn_openclaw_async(p, depth=1, model="openai/gpt-4o", tools=my_tools) for p in payloads],
        return_exceptions=True,
    )

    result_paths = [
        "/tmp/section_competitive.md",
        "/tmp/section_customers.md",
        "/tmp/section_trends.md",
    ]

    for summary, path in zip(summaries, result_paths):
        if isinstance(summary, BaseException):
            print(f"Child raised exception for {path}: {summary}")
            continue
        if is_error(summary):
            print(f"Child failed for {path}:", summary)
            continue
        content = read_result(path)
        if content is None:
            print(f"WARNING: no result file at {path}")
        else:
            print(f"Merging {path} ({len(content)} chars)")
            # merge content into parent output ...

---

Strategy C — Fire-and-Forget

The parent delegates a sub-task and immediately continues its own work. The child writes results to a known file path. The parent checks at a planned merge point.

Parent:  ──[spawn child]──────────────────────────[merge point]──▶ continue
Child:            └──[work independently]──[write result file]──▶ done

import asyncio
from spawn_openclaw import spawn_openclaw_async, is_error, read_result

async def main():
    child_result_path = "/tmp/child_analysis.md"
    payload = {
        "main_task_title": "Refactor authentication module",
        "progress_so_far": (
            "Audit complete. Parent is now rewriting core auth logic. "
            "Child is assigned to analyse test coverage gaps in parallel."
        ),
        "sub_task": (
            f"Read `/tmp/audit_report.md`. Identify which functions lack test coverage. "
            f"Write a markdown report of gaps to `{child_result_path}`. "
            f"Include function name, file, and suggested test cases for each gap."
        ),
    }

    # Spawn — returns immediately, child runs in background
    child_task = asyncio.create_task(
        spawn_openclaw_async(payload, depth=1, model="anthropic/claude-opus-4-6", tools=my_tools)
    )

    # Parent does its OWN work right now
    await do_parent_work()

    # Merge point — collect child
    try:
        summary = await child_task
    except (ValueError, FileNotFoundError) as exc:
        print("Child raised configuration error:", exc)
        return
    if is_error(summary):
        print("Child failed:", summary)
    else:
        content = read_result(child_result_path)
        if content is None:
            print("WARNING: child did not write expected result file.")
        else:
            await integrate_child_output(content)


async def do_parent_work():
    pass  # replace with actual parent steps

async def integrate_child_output(text: str):
    print(f"Merging {len(text)} chars from child...")

Rules for fire-and-forget

1. Always specify result_path in sub_task — it is the only rendezvous.
2. Plan your merge point before spawning — know exactly when the parent will need the child's output.
3. Use read_result() — returns None safely on any filesystem error (missing file, permission denied, etc.).
4. One result file per child — if a child produces multiple artefacts, have it write a manifest JSON listing them all.
5. Don't fire-and-forget if parent needs the result immediately — use Sequential instead.

---

Error Handling

What raises vs. what returns an error string:

Situation	Behaviour
Anthropic API error (network, rate limit, etc.)	Returns JSON error string — never raises
Empty or non-text API response	Returns JSON error string — never raises
depth >= MAX_DEPTH	Raises ValueError — programmer error, fix your call
Missing required payload key (main_task_title, progress_so_far, sub_task)	Raises ValueError — fix your payload
Non-JSON-serializable value in payload	Raises ValueError — fix your payload
SKILL.md not found	Raises FileNotFoundError — fix your path config

Always check with is_error() after a successful call. Wrap the call itself in try/except if you need to handle the two programmer-error exceptions gracefully:

try:
    summary = spawn_openclaw(payload, depth=1)
except (ValueError, FileNotFoundError) as exc:
    print("Configuration error:", exc)
    raise  # or handle

if is_error(summary):
    import json
    err = json.loads(summary)
    print("Runtime error:", err["error"])
    print("Partial results at:", err.get("partial_results"))  # may be None
    # decide: retry, fallback, abort parent
else:
    # success — read result files
    result = read_result("/tmp/some_output.md")
    if result is not None:
        # merge result ...
        pass
    else:
        print("WARNING: child did not write expected result file.")

---

Anti-Patterns to Avoid

Anti-Pattern	Why It's Bad	Fix
Sending the full conversation history as progress_so_far	Wastes tokens; child gets confused	Summarize: only what the child needs
Including secrets in progress_so_far	Snapshot is sent to Anthropic API and visible to child	Strip API keys, passwords, tokens, and personal data before spawning
Passing overly-permissive tools to children	Children gain filesystem or network access beyond what their sub_task needs	Scope tools to minimum required capability; omit tools= if the task only needs text output
Vague sub_task like "handle the rest"	Child doesn't know what to do	Be explicit: inputs, steps, output location
Spawning for a 2-line task	Overhead > benefit	Do it in the parent
Not writing a progress snapshot before spawning	Parent loses state if it crashes	Always freeze state first
Omitting tools= when sub_task requires file I/O	Child is a pure LM — it cannot read or write files; read_result() always returns None	Pass tool definitions or collect results from the summary string instead
Ignoring is_error() on child summary	Silent failures; parent merges nothing	Always check before reading result files
Fire-and-forget with no result file	No rendezvous; parent can't collect output	Always specify result_path in sub_task
Awaiting fire-and-forget child immediately after spawn	Defeats the purpose	Put await child_task at the merge point
Omitting depth= when spawning from inside a child	Depth check never triggers; runaway trees	Always pass depth=current_depth + 1
Child spawning further children without explicit permission	Runaway tree; hard to debug	Only spawn if sub_task explicitly says so

---

Quick Reference Card

SPAWN CHECKLIST
───────────────────────────────────────────
[ ] Sub-task is genuinely separable?
[ ] depth= will stay within MAX_DEPTH (default 3)?
[ ] Progress snapshot written (parent state frozen)?
[ ] main_task_title: ≤ 10 words, stable
[ ] progress_so_far: dense summary, no raw dumps
[ ] sub_task: self-contained, explicit result_path

STRATEGY SELECTION
[ ] Parent needs result before next step?        → Sequential (A)
[ ] Multiple children, all needed before merge?  → Parallel-gather (B)
[ ] Parent has its own work to do right now?     → Fire-and-forget (C)

AFTER EVERY SPAWN
[ ] is_error(summary) checked?
[ ] read_result(path) used (handles missing files safely)?
[ ] None result handled — don't merge silently?

FIRE-AND-FORGET EXTRAS
[ ] result_path agreed before spawning?
[ ] merge point placed after parent's own work?