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Etch is the hosted compliance layer around world-model-mcp, the open-source memory server it wraps. The OSS core is MIT-licensed and ships everything you need to run locally. Etch adds KMS-backed keys, a public transparency log, subscription billing, and an operator dashboard.
Open-source core
pip install world-model-mcp, the OSS Python servernpm i world-model-mcp, the TypeScript SDK- Set
WORLD_MODEL_AUDIT_LOG=onto enable the signed audit chain locally
Etch (hosted)
- KMS-encrypted signing keys, plaintext never at rest
- Public transparency log with signed head (split-view resistance)
- Scoped tokens: application, auditor, operator (segregation of duties)
- Stripe billing + subscription state machine
- Operator dashboard for rotate + sweep actions
Auditor tooling
Install etch-verify and run it against any Etch project. The
verifier walks the transparency log, checks each chain hash, and verifies
the hybrid Ed25519 + SLH-DSA signature on the head. No network access to
Etch required after the initial download, supports air-gapped audit.
Endpoint catalog
Every endpoint below appends to your per-project Etch chain, cross-references
the underlying OSS event by id, and is chain-signed under your KMS-managed
hybrid key envelope. All exercisable from the
etch-record
CLI (single invocation composes every layer via if X is not None
blocks so any subset can fire together).
Governance primitives (7 endpoints)
POST /v1/etch-chain/governance-record- 7-field extended governance schema (policy_hash + authority + assumptions + uncertainty + invalidation + mission + terminology + context)POST /v1/etch-chain/model-card-attestation- session-scoped model_card_hash + system_prompt_hash + policy_hash + model_idPOST /v1/etch-chain/session-risk-score- upstream vendor's risk score at each eventPOST /v1/etch-chain/autonomy-level- L0-L3 or custom-string per eventPOST /v1/etch-chain/supersession-edge- intent-tagged supersession + depends-on DAGPOST /v1/etch-chain/signed-dissent- second-line-of-defense signed disagreement (multi-key)
Ingest and halt (3 endpoints)
POST /v1/import- bulk ingest adapter (otel-gen-ai / langsmith / cloudtrail / vercel-ai / custom)POST /v1/etch-chain/stop-condition- explicit halt event; verifier flags post-halt writesGET-family session-scope chain view viaetch-chain-verify --session
Recoverability and continuity (verifier-only, 3 checks)
- Recoverability measurement (time-to-reconstruct + evidence-completeness score)
- Functional continuity tracking (walk a decision back through DAG to its evidence path)
- Hot / cold storage split with Merkle-path verification against cold archive
Drift and corrigibility (verifier-only, 3 checks)
- Policy-drift detector plus 8-category drift-detection engine (mission / assumption / confidence / evidence / scope / terminology / authority / context)
- Corrigibility self-audit (zero-challenge high-volume policies flagged)
Enterprise and admissibility (4 endpoints)
POST /v1/etch-chain/hsm-attestation- BYOK with vendor attestation (tpm2 / yubikey / aws-nitro / gcp-shielded / azure-attestation / sev-snp / intel-tdx)POST /v1/etch-chain/cross-chain-reference- Etch-to-Etch federation (chain_id + epoch + event_hash tuple, offline + optional online verifier)POST /v1/etch-chain/custody-export- self-authenticating JSON bundle aligned with FRE 902 (11 / 13 / 14) or eIDASPOST /v1/etch-chain/postmortem- signed retrospective with about_event_id, finding, corrective action + signer, optional retroactive confidence downgrade
Operational polish (3 endpoints)
POST /v1/etch-chain/artifact-hash- SHA-256 of a referenced artifact; client-side hashing so raw bytes never leave the machinePOST /v1/etch-chain/idempotency-collapse- retry-storm dedup keyed on (principal, scope, tool_version, argument_hash); append-only counter chainPOST /v1/etch-chain/learning-persistence- cross-session signed knowledge updates with propagation semantics (override_prior / augment_prior / deprecate_prior)