GRAFOMEM CGR Capture

grafomem-cgr

An MCP server that lets a coding agent record its own judgments and how they turned out, against your GRAFOMEM Cloud tenant.

The model is capture now, score later. Every time your agent makes a call it could be wrong about — "this deploy is safe", "this scan is clean", "this review finding is real" — it records the judgment. Later, when reality settles, it records the outcome. The two are joined by a work_item_id you choose. What accumulates is an append-only, attributable record of judgments and their results.

This package is the capture half only. It writes to your tenant; it does not compute, serve, or display scores.

cgr.cosign.v1 verifier (optional extra)

Beside the capture client, this package also ships a reference verifier for the cgr.cosign.v1 two-party co-signature envelope — grafomem_cgr.cosign_verify.verify(record, registry, ledger, trusted_issuers), implementing docs/cgr/cgr-cosign-v1-spec.md §8 (amended by decisions 0010 and 0011). trusted_issuers is required (§8.2a issuer pinning): a collection of issuer key ids with no default and no trust-everything path — omitting it or passing an empty set rejects, rather than trusting the record's self-declared issuer. It is the second, independent reference implementation (the first is @gns-foundation/cgr-verify, JS); both pass the same 28-vector conformance corpus at conformance/cgr-cosign-v1/ with zero verdict disagreements. Install its deps with the extra:

pip install grafomem-cgr[verify]      # rfc8785 + cryptography

Capture does not depend on it; the extra is verifier-only.

What it is not

• It does not score anything at capture time, and it does not read scores back into your session.
• It does not make your agent safer or gate anything. Nothing is blocked, approved, or prevented.
• It is not a compliance, audit, or security product.
• Scoring on GRAFOMEM Cloud is single-dimension today: all judgment/certify decisions score under one dimension regardless of domain. The domain you pass is stored durably per decision (see below), so it can be attributed later — but it is not scored separately yet.

Requirements

A GRAFOMEM Cloud account. The free tier is sufficient — expected volume is a handful of decisions per day. Note that governed decisions meter as real usage on your plan; the server prints your current usage on startup so this is never a surprise.

Install & configure

One command, plus environment variables — no repo checkout, no launcher script.

Claude Code:

claude mcp add grafomem-cgr --scope user \

--env GRAFOMEM_CGR_TENANT_KEY=sk_your_api_key \ --env GRAFOMEM_CGR_TENANT=your_tenant_id \ --env GRAFOMEM_CGR_ROLE_KEYS_JSON='{"cc-builder@acme":"<64-hex public key>"}' \ -- uvx grafomem-cgr

Or any MCP client that reads a JSON config:

{

"mcpServers": { "grafomem-cgr": { "command": "uvx", "args": ["grafomem-cgr"], "env": { "GRAFOMEM_CGR_TENANT_KEY": "sk_your_api_key", "GRAFOMEM_CGR_TENANT": "your_tenant_id", "GRAFOMEM_CGR_ROLE_KEYS_JSON": "{\"cc-builder@acme\":\"<64-hex public key>\"}" } } } }

Environment

Role keys

A role handle (cc-builder@acme) is the identity a judgment is attributed to. Its agent_key is a stable Ed25519 public key, 64 hex characters — the subject the record binds to. Generate one per role:

openssl genpkey -algorithm Ed25519 -out cc-builder.pem

openssl pkey -in cc-builder.pem -pubout -outform DER | tail -c 32 | xxd -p -c 64

Keep the private half. This version does not use it — it binds to the public key only — but per-decision proof-of-possession is planned hardening, and holding the private key is what will let you prove the identity is yours.

Tools

`cgr_record_decision` — record a judgment.

agent_confidence is accepted by the tool schema for forward compatibility but is not currently written to the decision record. Don't rely on it being stored.

Only judgment + certify moves a score. A rule decision is deterministic and carries no reputational weight — tag honestly.

`cgr_record_outcome` — record how it turned out.

An unrecognised `result` is a deliberate no-op. The decision stays pending rather than being resolved on a guess — falsely resolving a decision corrupts the record permanently. Mapped labels are: deploy_succeeded, deploy_healthy, ci_passed, migration_applied, merge_landed, pr_merged, scan_clean, no_vuln_confirmed, review_confirmed, finding_correct, bug_confirmed (success); deploy_failed, deploy_rolled_back, migration_failed, ci_failed, merge_reverted, vuln_found, secret_found, review_refuted, finding_wrong, bug_not_real (failure).

Safety properties

• Tenant pinning. You declare the tenant up front. The pin is enforced at startup *and* re-checked against the tenant the API actually resolved on every decision response — so a rotated or mistaken key cannot quietly write somewhere else.
• Denylist. GRAFOMEM_CGR_FORBIDDEN_TENANTS refuses named tenants outright.
• Key custody. The caller picks a role *handle*; the server injects that role's key. A tool call can never supply an arbitrary key or target another tenant.
• Fail-open. If the server is misconfigured it exits non-zero and simply doesn't load. Your session continues unblocked, with no tools registered. A refused tool call returns an error as normal tool output rather than crashing the MCP server.
• Domain durability. domain is sent as a dedicated field and stored server-side, per decision, in the never-encrypted CGR-readable decision parameters as cgr_domain — in the signed decision record, not in a client-side log. selftest includes a durability guard that re-reads the decision it just wrote and aborts loudly if cgr_domain did not round-trip, rather than silently recording a domainless decision.

CLI

grafomem-cgr                 # run the stdio MCP server (the default)

grafomem-cgr setup # register your role identities on the tenant (idempotent) grafomem-cgr selftest --handle cc-builder@acme --domain deploy-verification

selftest closes the loop once — decision → durability guard → outcome → score read — and prints the movement and the meter. Run it before wiring the server into a session.

Links

• grafomem.com · docs.grafomem.com
• Source · Issues

MIT licensed.