Ran Shem Tov
9a12dcc345
Cancel handling was asymmetric in both languages: the TypeScript-shaped
sentinel was only recognised on the outer envelope, so a cancel that arrived
wrapped as {"response": {"status": "cancelled"}} was reported to the model as
"did not pick a time". Both tools now check the sentinel at both levels, and
the test matrix covers the shape it missed (three cases fail without the fix).
The TypeScript tool also coalesced the label with ?? where Python uses or, so
an empty label swallowed a valid time; both now fall back the same way.
Frontend and probes:
- The headless resume waited on a single animation frame, which never fires in
a background tab, stranding the run. A timer races it and the resume fires
once, whichever lands first.
- The picker latches after the first answer, so a second click cannot race the
resume already in flight.
- A rejected resume now replaces the green "Booked" badge with a failure state
instead of leaving a success the user never got.
- The headless probe searched the whole page for booking words, which the
demo's own static copy already satisfies; it now reads assistant bubbles only
and matches phrases the page does not contain.
- The pick-path spec asserted a bubble was visible, which the pre-pause bubble
already satisfies; it now asserts the post-resume narration. The headless
spec scopes the picker to the app-surface pane, which is the contract it
claims to hold.
Prose and fixtures:
- The dedicated-mount rationale named the wrong tool: the in-chat demo
registers book_call, and the real collision is the shared agent's own
immediate schedule_meeting. Corrected in the parity notes and both tools.
- The TypeScript integration no longer cites Python API names, and the picker
no longer cites a slot generator that does not exist.
- The shared docs no longer describe a hook the embedded snippet does not
show, no longer place a standard interrupt's payload on event.value, and
carry the correct RUN_FINISHED outcome shape.
- The d4 fixture edits are back to UTF-8 literals, dropping 86 lines of
re-encoding noise so only the six intended key changes remain.
- The agent package exposes a test script, so the new unit test is runnable.
Showcase aimock
Tagline: aimock fixture-directory layout, context-routing semantics, schema
validation, drift-risk surface, and the manual add/update fixture flow. For
service reconstruction (Railway image / startCommand / fixture URLs) see
./RAILWAY.md. For matcher semantics / fixture-authoring
gotchas (sequenceIndex, hasToolResult, context mirroring) see
../GOTCHAS.md.
Deterministic LLM fixture server for showcase E2E testing. Replaces real LLM API calls (OpenAI, Anthropic, Gemini) with pre-recorded responses so Playwright tests can run PR-gated in CI without API keys and without rate limits or non-determinism.
Railway pulls ghcr.io/copilotkit/aimock:latest directly (no wrapper image). The fixtures in this directory are loaded at boot via GitHub raw URLs configured in the Railway service's startCommand.
What aimock is
aimock (@copilotkit/aimock) is a general-purpose LLM mock server. It speaks the OpenAI, Anthropic, and Gemini REST shapes (including SSE streaming), loads fixtures from disk at startup, and responds to incoming chat completions by matching the user's message text against fixture match criteria.
The showcase deployment runs aimock in proxy mode — --proxy-only with real upstream URLs configured for each provider. Unmatched requests are forwarded to the real API; matched requests short-circuit with the fixture response. This makes the sidecar safe to deploy as a general-purpose smoke-test aid: tests that hit fixture-matched prompts get deterministic responses, and anything else just falls through.
Directory Structure
showcase/aimock/
shared/ Fixtures loaded by ALL integrations (smoke, universal prompts)
d4/ D4-depth fixtures — per-integration, single-demo coverage
<slug>/ One directory per integration slug (e.g. langgraph-python/)
d6/ D6-depth fixtures — per-integration, all-pills coverage
<slug>/ One directory per integration slug
feature-parity.json Legacy flat fixture file (pre-context-routing)
smoke.json Minimal smoke fixture
README.md This file
Context routing. D4 and D6 fixtures use aimock's --context-field flag to scope fixture matching by integration. Each integration's dev server passes its slug as the context value in LLM requests (via X-AIMock-Context header or request body field). Aimock only considers fixtures whose match.context equals the incoming context value, so d4/langgraph-python/ fixtures never interfere with d4/mastra/ fixtures even if they share the same userMessage pattern.
Per-integration isolation. Every <slug>/ directory contains fixtures specific to that integration. This prevents cross-contamination: if mastra needs a different tool name than langgraph-python for the same demo, each has its own fixture file. The shared/ directory holds fixtures that apply regardless of context (e.g., smoke checks, universal greeting prompts).
Fixtures in this directory
feature-parity.json— 35+ fixtures covering the nine showcase demos across 17 packages: agentic chat (weather, backgrounds, themes), tool rendering (pie/bar charts, weather cards), HITL (plans, steps, approvals), Sales Dashboard (deals, pipelines, todos), and assorted meeting/flight/greeting prompts. Consumed by the per-packagetest_e2e-showcase-on-demandPlaywright suites and loaded at Railway boot via GitHub raw URL.smoke.json— a single minimal fixture (userMessage: "Respond with exactly: OK"→content: "OK"). Used by/api/smokeendpoints in each package to verify the aimock → package → UI round-trip without depending on a real agent.
Fixture match semantics: userMessage is a substring match against the last user turn. First fixture to match wins, so more specific prompts should appear before more generic ones (see the "Based on the following context, write a concise" entry that precedes the generic report / plan fixtures to protect CrewAI's startup probe).
Sync policy
Fixtures are hand-maintained. There is no automated capture, no scheduled re-recording, and no drift-detection job that compares fixture responses against what a real LLM would say. The authoritative behavior is whatever is checked in.
The safety net is two-layered load-time validation, not behavioral verification:
- Load-time schema validation (
--validate-on-loadin the RailwaystartCommandand in every test entrypoint that boots aimock) — the container refuses to start if any fixture uses an unrecognized response key (e.g.textinstead ofcontent). See #3973. - CI schema validation (
showcase/scripts/__tests__/aimock-fixtures.test.ts) — theshowcase_validateworkflow runsloadFixtureFile+validateFixturesfrom@copilotkit/aimockagainst everyshowcase/aimock/*.jsonon every PR. A broken fixture fails the PR before merge.
Neither layer catches behavioral drift — if a package's agent code changes what it asks the LLM (new prompt, new tool, renamed tool), the existing fixture keeps matching and keeps returning the old response. The test either keeps passing (wrong assertion) or fails at the UI-assertion layer (missing tool call, missing text), and a human has to trace it back to the fixture.
Adding or updating a fixture
The process is manual. There is no CLI for this directory specifically — aimock's upstream --record mode can proxy real API calls and write fixtures, but the showcase repo does not wire it up and does not commit recorded fixtures.
- Identify the user prompt your test issues and decide what response you need (plain text, a tool call, an error).
- Add an entry to
feature-parity.jsonunderfixtures. Keep more specificuserMessagematches above more generic ones. Valid response keys:content,toolCalls,error,embedding. - Run the fixture-validation suite locally:
pnpm --filter @copilotkit/showcase-scripts test aimock-fixtures - Run the per-package E2E against the new fixture:
./showcase/scripts/run-e2e-with-aimock.sh <slug> [test-filter] - Ship it. Fixture changes take effect on the next Railway service restart (aimock fetches fixtures from GitHub raw URLs at boot).
When a package's agent code changes in a way that changes its LLM calls, the person making the change is responsible for updating the corresponding fixture. There is no automation to remind you.
Drift risk
Drift surfaces as flaky or silently-wrong E2E tests, not as a dedicated signal. Symptoms and how to respond:
- Playwright assertion fails on a UI element that depends on a tool call (
WeatherCardmissing, chart not rendering) → the agent is now calling a differently-named tool than the fixture has; update the fixture'stoolCalls[].name/arguments. - Assertion on assistant text fails → the agent's prompt changed; either update the fixture's
match.userMessageto the new prompt substring or update the fixture'scontent. smoke.jsonhealthcheck fails against a deployed package (/api/smokereturns non-OK) → either the package's smoke route changed or aimock is down; check the Railway service and the smoke-monitor workflow.- Container fails to start post-deploy → load-time validation caught a broken fixture; CI should have caught it first, investigate why it didn't.
There is no scheduled drift-detection job that compares fixture responses against live LLM output. If this becomes a problem, the path forward is to wire aimock's --record mode into a periodic workflow that re-captures against real providers and diffs against checked-in fixtures — but that's not built today.
Related workflows
test_e2e-showcase-on-demand.yml(historicallyshowcase_aimock-e2e.yml) — triggered by/test-aimock <slug>PR comments orworkflow_dispatch. Installs@copilotkit/aimock@latest, boots it withfeature-parity.json, spins up the target package's dev server againstOPENAI_BASE_URL=http://localhost:4010/v1, and runs the package's Playwright suite. Posts pass/fail back to the PR.showcase_validate.yml— runs fixture schema validation (aimock-fixtures.test.ts) on every PR that touchesshowcase/**.showcase_deploy.yml— builds and deploys all showcase services. aimock is no longer in this workflow's matrix (Railway pulls the upstreamghcr.io/copilotkit/aimock:latestimage directly).showcase_smoke-monitor.yml— every 15 minutes, polls/api/smokeon all deployed showcase packages. Those smoke endpoints internally hit aimock'ssmoke.jsonfixture to verify the full stack.