@cesteral/contract-schema

The canonical governance-contract surface for the Cesteral MCP ecosystem — the single source of truth shared by the MCP servers (mcp-open-advertising) and the governance layer (cesteral-intelligence).

Where @cesteral/contract-hash owns how a tool definition is hashed, this package owns the shape of what gets governed:

• Tool annotations — the cesteral.* namespace, in two deliberately different-strictness faces:
  • Authoring types (CesteralToolAnnotations, CesteralEntityWriteToolAnnotations, …) — the strict contract MCP-server authors write against with satisfies.
  • Validation schema (cesteralAnnotationSchema, parseCesteralAnnotation) — the loose shape governance parses untrusted tool lists with, so it can apply contract-promise checks (requiresValidation, …) as specific admission reason codes rather than a generic parse failure.
• Canonical enums — CESTERAL_WRITE_OPERATIONS / writeOperationSchema and canonicalEntityKindSchema / CanonicalEntityKind.
• contractId derivation — deriveContractId, safeDeriveContractId, slugSchema.
• Governed response shapes — dryRunResultSchema, normalizedEntitySnapshotSchema, dispatchedCapabilitySchema, effectDryRunResultSchema, and their TS mirrors.
• Release attestation manifest — cesteralManifestSchema.

import {
  parseCesteralAnnotation,
  deriveContractId,
  cesteralManifestSchema,
} from "@cesteral/contract-schema";

const parsed = parseCesteralAnnotation(tool.annotations?.cesteral);
if (parsed.success) {
  // parsed.data.contractId === deriveContractId(slug, slug, version)
}

Each TS authoring type and its Zod validation mirror are pinned together by the package's type-tests — the two faces cannot silently drift, and any value satisfying an authoring type is guaranteed to parse under the schema.