Install
$ agentstack add skill-bluem-dev-grace-skill ✓ scanned · ✓ verified, works with Claude Code, Cursor, and more.
Security review
✓ PassedNo issues found. Passed automated security review. · v0.1.0 How review works →
- ✓ Prompt-injection patterns
- ✓ Secret / credential exfiltration
- ✓ Dangerous shell & filesystem operations
- ✓ Untrusted network calls
- ✓ Known-malicious package signatures
What it can access
- ✓ Network access No
- ✓ Filesystem access No
- ✓ Shell / process execution No
- ✓ Environment & secrets No
- ✓ Dynamic code execution No
From automated source analysis of v0.1.0. “Used” means the capability is present in the source — more access means more to trust, not that it’s unsafe.
Verified badge
Passed review? Show it. Paste this badge into your README, it links to the public security report.
Reliability & compatibility
Declared compatibility
Compatibility is declared by the source manifest. End-to-end runtime verification is coming, see below.
We're building live execution health for every listing: tool-call success rate, median latency, uptime, and last-checked timestamps, measured, not self-reported. It isn't live yet, so we don't show numbers we can't stand behind.
How agent discovery & health will work →About
Grace — Realization & Convergence Engine — Skill Runtime
Grace is the realization layer that sits between cognitive reasoning and the real world. It is the structural sister of Etta Cognitive OS: where Etta expands ambiguity into structured intent, Grace collapses that intent into a single deterministic, verifiable, canonical artifact.
Core principle: Etta decides → Grace converges and executes → Workspace persists.
Grace does not reason, brainstorm, or explore alternatives. It does not "think out loud." It takes structured intent as input and produces canonical, governed reality as output — or it halts.
Etta ↔ Grace Separation Law
| | Etta (Cognition) | Grace (Realization) | |---|---|---| | Function | Expands possibility space | Collapses possibility into reality | | Output | Goals, hypotheses, decisions, confidence | Canonical artifacts, execution state | | Allowed to reason probabilistically | Yes | No — convergence over exploration | | Governs canonicality | No — may reference artifacts only | Yes — sole authority | | May expand intent | Yes — this is its job | No — strictly forbidden | | May bypass the other | No | No |
Global system loop: Etta → Grace → Workspace → MCP → Grace → Etta
System states: Stable / Degraded / Failure — determined by artifact consistency, resolved execution state, and a synchronized workspace.
Feedback dynamics: Grace constrains future cognition (its canonical artifacts become ground truth for Etta); Etta enriches future execution (its refined intents improve Grace's convergence quality).
System Architecture
ETTA INTENT (structured, schema-bound)
│ Intent Contract
▼
GRACE REALIZATION LAYER
├── Convergence Engine ← collapse multiple interpretations into ONE executable path
├── Execution Graph Builder ← compile intent into a DAG (node = unit of work, edge = dependency)
├── Scheduler ← resolve ready nodes, dispatch in parallel
├── MCP / Tool Executor ← stateless calls to MCPs, APIs, Claude, file systems
├── Verification Engine ← validate outputs against intent + identity rules
├── Artifact Manager ← canonical commit, version lineage, replace semantics
└── Governance Core ← invariant enforcement + conflict arbitration (supreme authority)
│
▼
WORKSPACE (shared state) ← artifact registry, execution logs, lineage graph (single source of truth)
│
▼
MCP / EXTERNAL SYSTEMS ← non-semantic execution endpoints, no correctness assumed
│
▼
FEEDBACK → ETTA ← canonical artifacts + execution state feed future cognition
Authority hierarchy inside Grace (highest → lowest): Governance Core → Contracts → Runtime → Protocol → Error Ontology → Artifact Identity → Behavior Model
Ecosystem-wide rule: Grace's Governance Core is the supreme authority on the realization side, exactly as Etta's Critic Engine is supreme on the cognition side. Neither layer bypasses the other: Etta never writes directly to Workspace, and Grace never expands intent on its own.
Core Execution Loop
Every Grace cycle follows this strictly ordered, deterministic state machine:
INTAKE → CONTEXT RESOLUTION → CONVERGENCE → PLAN GENERATION → EXECUTION → VERIFICATION → COMMIT → FEEDBACK
Steps:
- Intake — receive structured intent (from Etta or any structured caller). No interpretation expansion allowed.
- Governance pre-check — Governance Core validates the intent against global invariants before anything else runs.
- Context Resolution — resolve Workspace state, artifact identity, and historical lineage relevant to this intent.
- Convergence Engine — reduce multiple potential interpretations into a single deterministic execution path. Ambiguity is eliminated, never explored.
- Execution Graph Builder — compile the converged path into an atomic, ordered, dependency-aware DAG.
- Scheduler — compute the ready set (all dependencies completed) and dispatch eligible nodes, in parallel where possible.
- MCP / Tool Executor — execute each node statelessly against MCPs, APIs, Claude, or local compute. No side effects assumed correct.
- Verification Engine — validate node and aggregate outputs against intent constraints and identity rules. Hard gate — no bypass.
- Artifact Manager — on verification pass, commit the canonical artifact (CREATE / REPLACE / MERGE / COLLAPSE / ARCHIVE). Enforces one canonical state per
artifact_id. - Workspace Sync — persist artifact, execution log, and lineage update as the new single source of truth.
- Feedback — return canonical artifacts and execution state to Etta for knowledge-graph update and future reasoning.
Invariants — never violate:
- No artifact may be committed without passing Verification (hard gate, no bypass)
- No canonical-state duplication — exactly one canonical artifact per
artifact_id, ever - No execution without Governance Core approval of the originating intent
- Grace never expands intent — it only collapses it; expansion is exclusively Etta's responsibility
- All contracts are schema-validated, versioned, and immutable once emitted — corrections require new versions, not edits
- MCPs are non-semantic endpoints — no layer may assume correctness of their output without verification
- If Governance Core cannot resolve a conflict, the system enters a safe halted state — it never guesses
Implementation
Read references/implementation.md for full Python code covering:
GraceRuntime— top-level orchestrator (execute())GovernanceCore/InvariantRegistry— invariant enforcement gate, first to initialize, last to be bypassedExecutionEngine— graph build + dispatchExecutionGraph/ExecutionNode/Scheduler— DAG model and ready-node resolutionMCPExecutor(async) — parallel node executionMCPClient/MCPAdapter— real tool invocation with governance validation before and afterArtifact/ArtifactManager— canonical commit and identity enforcementEttaInterface/EttaToGraceTranslator— the Etta → Grace bridgeErrorRecovery— minimal recovery dispatcher- Worked examples: minimal run, full Etta→Grace flow, direct MCP tool call
Read references/schemas.md for all canonical contracts and data shapes:
- Intent / Artifact / Execution / Verification / Reconciliation / State Contracts
- Base Contract structure (shared by all contract types)
- Execution Graph Node schema + execution state enum
- Global Message Envelope (shared with Etta)
- Failure / Error schema and error taxonomy
- Artifact lifecycle, commit semantics, and realization states
Read references/governance.md for the Governance Core model:
- Conflict classification (Type A–D) and the resolution pipeline
- Severity matrix (S0–S5), detectability spectrum, recoverability classes
- Recovery algorithm framework and containment architecture
- Escalation rules and the safe-halt condition
When Implementing Grace as a SKILL/Plugin
Minimal Viable Grace (context-window only, no external persistence)
For an LLM agent operating inside a single context window (e.g., a Claude SKILL with no backing database), Grace state lives as a structured dict injected into reasoning:
grace_state = {
"intent": None,
"execution_graph": [], # list of node dicts: {id, deps, status, payload}
"artifacts": {}, # artifact_id -> canonical artifact dict
"execution_log": [], # append-only
"governance": {
"invariants_ok": True,
"open_conflicts": []
},
"runtime_state": "IDLE" # see references/schemas.md for full enum
}
Inject state into every planning step. Before any artifact write, run the Governance check inline. Never hold two "canonical" entries for the same artifact_id in artifacts.
As a Claude SKILL
The SKILL instructs Claude to:
- Treat any incoming structured intent (from Etta, from the user, or from a prior turn) as
Grace's Intake — do not silently reinterpret or expand it.
- Run a lightweight Governance pre-check: are required fields present, is the target
artifact_id known, are there open S4/S5 conflicts logged in state?
- Build an explicit, ordered execution plan (a DAG if there are independent sub-tasks) before
taking any action — even a "plan" of one node is still a plan.
- Execute steps, calling tools/MCPs as needed, treating their outputs as unverified until
checked against the original intent.
- Only after verification, "commit" the result — i.e., state plainly what the new canonical
answer/artifact is, superseding any prior draft.
- Log the cycle (what was decided, what was verified, what was committed) so future turns can
reference it as ground truth.
As a Python Plugin / External Agent
Use the full implementation from references/implementation.md. GraceRuntime wraps the entire intake → convergence → execution → verification → commit pipeline and exposes a single execute(intent) entry point for callers (Etta, a CLI, an API).
Failure Handling
| Failure | Response | |---|---| | Convergence failure (residual ambiguity) | Re-enter Convergence with updated constraints; bounded retries, then escalate | | Execution / MCP failure | Bounded retry; on exhaustion, roll back the node, mark it failed, block dependents | | Verification failure | Block commit; return to Planning or escalate to Governance Core | | Artifact identity collision | Halt the commit; route to the Reconciliation protocol | | Reconciliation failure (Workspace ↔ MCP divergence) | Iterative reconciliation loop until consistent, or declare non-recoverable | | Protocol / contract violation | Halt execution immediately; no state mutation permitted | | Governance conflict deadlock (S4/S5 severity) | System enters a safe halted state; manual intervention required |
Key Design Rules
- Convergence over exploration — Grace collapses ambiguity; it never explores it. Exploration is Etta's job.
- Canonical state is singular — exactly one canonical artifact per
artifact_id, at all times. - Verification gates every commit — no artifact reaches Workspace without passing verification. No exceptions.
- Contracts are immutable once emitted — corrections create new versioned contracts; nothing is edited in place.
- Workspace is the single source of truth — reconciliation always resolves toward Workspace state, not toward whichever system spoke last.
- MCPs guarantee nothing semantically — Grace verifies; it never assumes a tool's output is correct just because the call succeeded.
- Governance Core has the final word — an unresolved conflict halts the system safely rather than letting it proceed on a guess.
Source & license
This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.
- Author: bluem-dev
- Source: bluem-dev/Grace
- License: MIT
- Homepage: https://github.com/bluem-dev/Grace
Install and usage instructions live in the source repository linked above.
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Versions
- v0.1.0 Imported from the upstream source.