Duplicate carrier IDs are excluded loudly

outcome

Prevent ambiguous authored identity from entering the graph.

rule line 20 · specs/validation/duplicate-ids.sdp.md:20

If more than one carrier declares an ID, every duplicate site receives extract/duplicate-id and no ambiguous node is derived.

rule line 21 · specs/validation/duplicate-ids.sdp.md:21

Over a graph from any producer, every node whose id is carried by another node receives a conformance/duplicate-ids error; the extractor separately excludes ambiguous authored carriers through extract/duplicate-id.

2 unkeyed rules.

Verifying examples

Given a {firstCarrier: "TypeScript"} carrier declares {specId: "spec:fixture.duplicate"}
Given a {secondCarrier: "Markdown"} carrier declares {specId: "spec:fixture.duplicate"}
When the extraction root is read
Then both sites report {findingId: "extract/duplicate-id"}
Then no graph node is emitted for {specId: "spec:fixture.duplicate"}

Example space

Given a {firstCarrier:string} carrier declares {specId:string}
Given a {secondCarrier:string} carrier declares {specId:string}
When the extraction root is read
Then both sites report {findingId:string}
Then no graph node is emitted for {specId:string}

Verifier bindings

• spec:validation.duplicate-ids.dual-carrier · TypeScript and Markdown duplicates are both refused · declared · example enabled · specs/validation/duplicate-ids.dual-carrier.sdp.md

  External run evidence from test/self-hosting-duplicate-ids.test.ts

  Test anchors: test:protocol.duplicate-ids.dual-carrier. Specs verified by those bindings: spec:validation.duplicate-ids, spec:validation.duplicate-ids.dual-carrier.

  Run 1: external run evidence from vitest 4.1.10

  Build: CI 380 · Branch: feature/roadmap-and-slices-v0 · Commit: 34909918bf0be0e849959644401797191cae379f · Start: 2026-10-22T17:40:31.456Z · Stop: 2026-10-22T17:42:16.171Z

  Name	Suite	Result	Duration
  names self-hosting generation before collecting its filtered tracer	generated contract preflight	passed	47.15 ms
  names checkout generation before collecting its filtered example	generated contract preflight	passed	41.75 ms
  names both generations when an unfiltered suite lacks both contract trees	generated contract preflight	passed	52.17 ms
  matches a Vitest substring filter before collecting the self-hosting tracer	generated contract preflight	passed	42.03 ms
  matches a ./-prefixed filter before collecting the self-hosting tracer	generated contract preflight	passed	55.66 ms
  matches an absolute-path filter before collecting the self-hosting tracer	generated contract preflight	passed	55.97 ms
  does not require contracts for an unrelated Vitest filter	generated contract preflight	passed	94.09 ms
  proceeds for the unfiltered invocation once both contract trees are generated	generated contract preflight	passed	129.27 ms
  fails a pooled run that mutates repository-root generated state	pooled root generated-state sentinel	passed	83.33 ms
  passes a pooled run that leaves repository-root generated state untouched	pooled root generated-state sentinel	passed	83.32 ms
  derives the duplicate-ID verifier facts from the bound executable example	not recorded	passed	5140.53 ms
  executes the bound example against a fresh world	TypeScript and Markdown duplicates are both refused (spec:validation.duplicate-ids.dual-carrier)	passed	8.19 ms

Requirement drawing

Decisions

No decision record named.

• component:protocol.extract · the carrier and source pipeline · src/extract/index.ts:192 · layer application · context protocol

  Uses

  • component:protocol.graph · the one graph and its semantic decisions · src/graph/schema.ts:34 · layer domain · context protocol
  • component:protocol.model · the authored contracts and stable ids · src/model/anchors.ts:100 · layer domain · context protocol
  • component:protocol.notation · the leaf step codec · src/notation/slots.ts:261 · layer domain · context protocol
  • component:protocol.validate · one finding currency and ordered checks · src/validate/validators.ts:72 · layer domain · context protocol
• component:protocol.validate · one finding currency and ordered checks · src/validate/validators.ts:72 · layer domain · context protocol

  Uses

  • component:protocol.graph · the one graph and its semantic decisions · src/graph/schema.ts:34 · layer domain · context protocol
  • component:protocol.model · the authored contracts and stable ids · src/model/anchors.ts:100 · layer domain · context protocol
  • component:protocol.notation · the leaf step codec · src/notation/slots.ts:261 · layer domain · context protocol
• impl:protocol.duplicate-id-exclusion · excludes duplicated carrier ids from the graph · src/extract/index.ts:93

  Component: component:protocol.extract · the carrier and source pipeline · src/extract/index.ts:192 · layer application · context protocol

  Uses

  None.

• impl:protocol.duplicate-ids · rejects duplicate node identities from any graph producer · src/validate/validators.ts:263

  Component: component:protocol.validate · one finding currency and ordered checks · src/validate/validators.ts:72 · layer domain · context protocol

  Uses

  None.

Runtime observation: not tracked.

Runtime observation: not tracked.

Build attestations: not tracked.

Deployments: not tracked.

Bills of materials: not tracked.