openclaw-fenced-loop-skill — Fenced Task Leases, NodeGrid Governance & Iterative Multi-Worker Composer

openclaw-fenced-loop-skill (openclaw_fenced_loop + fenced-loop-executor) provides a 100% Python standard-library + SQLite WAL fenced task execution engine, declarative configuration grid (NodeGrid + GridLedger), Iterative Multi-Worker Artifact Composer (IterativeArtifactComposer), and JSON-RPC 2.0 Stdio MCP bridge for OpenClaw (ClawHub) and Hermes Brain × OpenClaw Hands pipelines.

Core Primitives

• Atomic CAS Lease-Epoch Fencing (FencedTaskStore): Increments lease_epoch (BEGIN IMMEDIATE + compare-and-swap) and mints an HMAC-SHA256 fence_token. Delayed checkpoints from stalled or reconnected gateway workers (epoch < current) fail closed with stale_epoch_rejected.

• Compaction-Safe Resume Packets: Every claim emits a bounded JSON resume packet (<= 320 bytes by default, governed by default_grid.json with automatic boundary expansion) so channel and code workers resume cleanly without replaying completed side effects.

• Declarative NodeGrid + ParameterBounds (expand_if_saturated): All behavioral capacities, lease TTLs, stage limits, and verification quorums live in externalized JSON (openclaw_fenced_loop/default_grid.json) with cross-parameter constraints and automatic axis expansion when empirical optima saturate initial grid bounds.

• Verification-Gated GridLedger (maker_id != checker_id): Tracks configuration cell transitions (represented -> applicable -> proposed -> dispatched -> evaluated -> verified -> promoted) and strictly blocks self-certification (maker_id == checker_id) or unverified promotion.

• IterativeArtifactComposer (Multi-Stage DAG Decomposition & Deterministic Manifests): Topologically validates and decomposes multi-stage builds (StageSpec) into fenced tasks in FencedTaskStore, binds downstream inputs to upstream stage digests, reuses unexpired bitemporal cached stages at zero execution cost, verifies new stages via an independent checker (maker_id != checker_id), and synthesizes a deterministic manifest digest.

Related MCP server: DeadBolt

Python API (openclaw_fenced_loop)

from pathlib import Path
from openclaw_fenced_loop import (
    FencedTaskStore,
    IterativeArtifactComposer,
    NodeGrid,
    StageSpec,
)

grid = NodeGrid.default()
store = FencedTaskStore(db_path=Path("./.fenced_composer.sqlite3"), grid=grid)
composer = IterativeArtifactComposer(store, grid=grid, regime="durable_multi_worker")

stages = [
    StageSpec(stage_id="schema_init", verb="emit_schema", payload={"rev": "v1"}),
    StageSpec(
        stage_id="compile_core",
        verb="compile_unit",
        payload={"module": "router"},
        depends_on=("schema_init",),
    ),
]

manifest = composer.execute_and_compose(
    build_id="release_01",
    stages=stages,
    maker_id="openclaw-maker-1",
    checker_id="hermes-checker-2",
    maker_fn=lambda ctx: {"built": ctx["stage_id"], "deps": ctx["upstream_digests"]},
    checker_fn=lambda ctx, out: out.get("built") == ctx["stage_id"],
)
print(manifest["manifest_digest"], manifest["cell_lifecycle_state"])

OpenClaw Skill & Stdio MCP Invocation

# Install in OpenClaw / ClawHub workspace:
openclaw skills install aidonerightcorp/openclaw-fenced-loop-skill

# Direct CLI action against a shared SQLite WAL ledger:
python3 scripts/fenced_loop_mcp_bridge.py --db ./.fenced_loop.sqlite3 enqueue \
  --task-id task-01 --verb execute --payload-json '{"step":"sync"}'

python3 scripts/fenced_loop_mcp_bridge.py --db ./.fenced_loop.sqlite3 claim \
  --worker-id openclaw-worker-1

# Mount as a JSON-RPC 2.0 Stdio MCP server in OpenClaw or Hermes mcp_servers:
python3 scripts/fenced_loop_mcp_bridge.py --db ./.fenced_loop.sqlite3 --mcp-stdio

Verification & Conformance Gates

PYTHONDONTWRITEBYTECODE=1 pytest -p no:cacheprovider -q

• Zero external runtime dependencies (sqlite3, hmac, hashlib, json, argparse stdlib only).

• Mechanical ZeroHardcodedValuesAstGate + DomainAgnosticNamingGate enforced in tests/test_grid_composer.py.

• Zero outbound network calls, zero telemetry, zero environment secret reads.