parallel_dispatch_runner not implemented; not-found path aborts the storyboard instead of grading not_applicable

[idemidenko]

Upstream report: adcontextprotocol/adcp#7232

Filing here because that issue's triage concluded the work is entirely in this repo and that "a human will need to file or update the adcp-client issue/PR". It has been deferred since 2026-09-04 for want of this issue.

Bug

The parallel_dispatch_runner test-kit contract is not implemented in the runner, and its not-found path emits an error instead of the spec-required stable not_applicable. The result is that idempotency/two_parallel_create_media_buy_calls_with_same_key_converge_on_one_resource hard-fails and the storyboard aborts at 9/11 rather than recording a clean skip at 10/11.

Observed against https://sales-agent.elementaltv.io/mcp on cache 3.1.20 with @adcp/sdk@13.0.2, still reproducing as of 2026-09-08:

Test-kit contract "parallel_dispatch_runner" is not configured on this runner.

The spec side is already complete

From the upstream triage on adcp#7232:

• The contract definition in the adcp repo is complete and correct (static/compliance/source/test-kits/parallel-dispatch-runner.yaml).
• idempotency.yaml already authorizes a stable not_applicable marker when the runner lacks parallel-dispatch support.
• runner-output-contract.yaml line 94 references PR feat(runner): conform storyboard output to adcp runner-output contract (#599) #611 as the intended implementation vehicle.

So no spec or storyboard change is needed — only this repo.

Two parts, per that triage

1. Implement parallel_dispatch_runner process_local mode in src/lib/testing/storyboard/parallel-dispatch.ts and the runner dispatch logic — Promise.all dispatch plus IDEMPOTENCY_IN_FLIGHT resolution — so idempotency rule 9 gets a real grade.
2. Fix the not-found path to emit stable not_applicable, so runners without the contract record a clean 10/11 skip instead of aborting.

Part 2 alone removes the false negative, and is independent of part 1.

Impact

Two of eleven steps hard-fail on every graded run for reasons unrelated to the agent under test, keeping the idempotency storyboard partial and the core track from passing. The step never reaches the agent at all. Both assertions it exists to gate — a replay returning the cached response, and IDEMPOTENCY_CONFLICT on key reuse with a changed payload — already pass elsewhere in the same storyboard, so the concurrency case is the only ungraded part.

[bokelley]

Thanks for filing! The upstream triage is clear and the code confirms both halves of this report.

Triage

Classification: Bug
Bucket(s): conformance, library
Status: ready-to-implement

What the experts said:

• ad-tech-protocol-expert: not_applicable is the correct canonical grade when parallel_dispatch_runner is absent; fixing gate ordering (not DETAILED_SKIP_TO_CANONICAL) is the right approach and is non-breaking.
• code-reviewer: Part 1 (implementation) is already complete in parallel-dispatch.ts; the only real bug is Part 2 — a single conditional at runner.ts:4721 suffices; the line 6762 gate is unrelated; a unit test is required.

My take: Part 1 (runParallelDispatches, dispatchOnceWithInflightRetry, IDEMPOTENCY_IN_FLIGHT resolution) is already implemented and wired in runner.ts:5328. Only Part 2 needs work: the general requires_contract gate at runner.ts:4721 fires before the parallel_dispatch field check at line 5187, mapping parallel_dispatch_runner absent to unsatisfied_contract instead of not_applicable.

Implementation scope:

• File: src/lib/testing/storyboard/runner.ts, line 4721 (runStoryboardStep / runStoryboardStepInternal).
• Change: At the top of the requires_contract gate, add a branch: when step.requires_contract === PARALLEL_DISPATCH_CONTRACT, return skip_reason: 'not_applicable' / skip: buildSkip('not_applicable', ...) — identical in shape to the parallel_dispatch field check at line 5187. The existing missing_test_kit_contract → unsatisfied_contract path for all other contracts stays untouched.
• Do not change DETAILED_SKIP_TO_CANONICAL — missing_test_kit_contract: 'unsatisfied_contract' is correct for rate_limit_trip and other operator-opt-out contracts.
• Test: Add a case to the runner's test coverage asserting that a step with requires_contract: 'parallel_dispatch_runner' and no matching entry in options.contracts produces skip_reason: 'not_applicable' and skip.reason: 'not_applicable', not unsatisfied_contract. task-map.test.ts exists; a runner-level test file may need to be created.
• Non-breaking: Changes a hard-fail to a stable skip (passed: true). Phase-level rollup paths (requiredPhasesNotApplicable vs requiredPhasesContractGated at runner.ts:3959/3978) are already compatible with the new routing.
• Changeset: patch — conformance runner bug fix.
• Checks: npm run ci:quick before push; schemas/public API not touched so ci:schema-check/ci:docs-check not required.

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Triaged by Claude Code. Session: https://claude.ai/code/session_01DsJ2bPZ8jAKsBcMgmNMjVT

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