# What does this PR do? This commit introduces a new FastAPI router-based system for defining API endpoints, enabling a migration path away from the legacy @webmethod decorator system. The implementation includes router infrastructure, migration of the Batches API as the first example, and updates to server, OpenAPI generation, and inspection systems to support both routing approaches. The router infrastructure consists of a router registry system that allows APIs to register FastAPI router factories, which are then automatically discovered and included in the server application. Standard error responses are centralized in router_utils to ensure consistent OpenAPI specification generation with proper $ref references to component responses. The Batches API has been migrated to demonstrate the new pattern. The protocol definition and models remain in llama_stack_api/batches, maintaining clear separation between API contracts and server implementation. The FastAPI router implementation lives in llama_stack/core/server/routers/batches, following the established pattern where API contracts are defined in llama_stack_api and server routing logic lives in llama_stack/core/server. The server now checks for registered routers before falling back to the legacy webmethod-based route discovery, ensuring backward compatibility during the migration period. The OpenAPI generator has been updated to handle both router-based and webmethod-based routes, correctly extracting metadata from FastAPI route decorators and Pydantic Field descriptions. The inspect endpoint now includes routes from both systems, with proper filtering for deprecated routes and API levels. Response descriptions are now explicitly defined in router decorators, ensuring the generated OpenAPI specification matches the previous format. Error responses use $ref references to component responses (BadRequest400, TooManyRequests429, etc.) as required by the specification. This is neat and will allow us to remove a lot of boiler plate code from our generator once the migration is done. This implementation provides a foundation for incrementally migrating other APIs to the router system while maintaining full backward compatibility with existing webmethod-based APIs. Closes: https://github.com/llamastack/llama-stack/issues/4188 ## Test Plan CI, the server should start, same routes should be visible. ``` curl http://localhost:8321/v1/inspect/routes | jq '.data[] | select(.route | contains("batches"))' ``` Also: ``` uv run pytest tests/integration/batches/ -vv --stack-config=http://localhost:8321 ================================================== test session starts ================================================== platform darwin -- Python 3.12.8, pytest-8.4.2, pluggy-1.6.0 -- /Users/leseb/Documents/AI/llama-stack/.venv/bin/python3 cachedir: .pytest_cache metadata: {'Python': '3.12.8', 'Platform': 'macOS-26.0.1-arm64-arm-64bit', 'Packages': {'pytest': '8.4.2', 'pluggy': '1.6.0'}, 'Plugins': {'anyio': '4.9.0', 'html': '4.1.1', 'socket': '0.7.0', 'asyncio': '1.1.0', 'json-report': '1.5.0', 'timeout': '2.4.0', 'metadata': '3.1.1', 'cov': '6.2.1', 'nbval': '0.11.0'}} rootdir: /Users/leseb/Documents/AI/llama-stack configfile: pyproject.toml plugins: anyio-4.9.0, html-4.1.1, socket-0.7.0, asyncio-1.1.0, json-report-1.5.0, timeout-2.4.0, metadata-3.1.1, cov-6.2.1, nbval-0.11.0 asyncio: mode=Mode.AUTO, asyncio_default_fixture_loop_scope=None, asyncio_default_test_loop_scope=function collected 24 items tests/integration/batches/test_batches.py::TestBatchesIntegration::test_batch_creation_and_retrieval[None] SKIPPED [ 4%] tests/integration/batches/test_batches.py::TestBatchesIntegration::test_batch_listing[None] SKIPPED [ 8%] tests/integration/batches/test_batches.py::TestBatchesIntegration::test_batch_immediate_cancellation[None] SKIPPED [ 12%] tests/integration/batches/test_batches.py::TestBatchesIntegration::test_batch_e2e_chat_completions[None] SKIPPED [ 16%] tests/integration/batches/test_batches.py::TestBatchesIntegration::test_batch_e2e_completions[None] SKIPPED [ 20%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_invalid_endpoint[None] SKIPPED [ 25%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_cancel_completed[None] SKIPPED [ 29%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_missing_required_fields[None] SKIPPED [ 33%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_invalid_completion_window[None] SKIPPED [ 37%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_streaming_not_supported[None] SKIPPED [ 41%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_mixed_streaming_requests[None] SKIPPED [ 45%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_endpoint_mismatch[None] SKIPPED [ 50%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_missing_required_body_fields[None] SKIPPED [ 54%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_invalid_metadata_types[None] SKIPPED [ 58%] tests/integration/batches/test_batches.py::TestBatchesIntegration::test_batch_e2e_embeddings[None] SKIPPED [ 62%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_nonexistent_file_id PASSED [ 66%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_malformed_jsonl PASSED [ 70%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_file_malformed_batch_file[empty] XFAIL [ 75%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_file_malformed_batch_file[malformed] XFAIL [ 79%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_retrieve_nonexistent PASSED [ 83%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_cancel_nonexistent PASSED [ 87%] tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_error_handling_invalid_model PASSED [ 91%] tests/integration/batches/test_batches_idempotency.py::TestBatchesIdempotencyIntegration::test_idempotent_batch_creation_successful PASSED [ 95%] tests/integration/batches/test_batches_idempotency.py::TestBatchesIdempotencyIntegration::test_idempotency_conflict_with_different_params PASSED [100%] ================================================= slowest 10 durations ================================================== 1.01s call tests/integration/batches/test_batches_idempotency.py::TestBatchesIdempotencyIntegration::test_idempotent_batch_creation_successful 0.21s call tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_nonexistent_file_id 0.17s call tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_malformed_jsonl 0.12s call tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_error_handling_invalid_model 0.05s setup tests/integration/batches/test_batches.py::TestBatchesIntegration::test_batch_creation_and_retrieval[None] 0.02s call tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_file_malformed_batch_file[empty] 0.01s call tests/integration/batches/test_batches_idempotency.py::TestBatchesIdempotencyIntegration::test_idempotency_conflict_with_different_params 0.01s call tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_file_malformed_batch_file[malformed] 0.01s call tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_retrieve_nonexistent 0.00s call tests/integration/batches/test_batches_errors.py::TestBatchesErrorHandling::test_batch_cancel_nonexistent ======================================= 7 passed, 15 skipped, 2 xfailed in 1.78s ======================================== ``` --------- Signed-off-by: Sébastien Han <seb@redhat.com> |
||
|---|---|---|
| .. | ||
| backward_compat | ||
| common | ||
| containers | ||
| external | ||
| integration | ||
| unit | ||
| __init__.py | ||
| README.md | ||
There are two obvious types of tests:
| Type | Location | Purpose |
|---|---|---|
| Unit | tests/unit/ |
Fast, isolated component testing |
| Integration | tests/integration/ |
End-to-end workflows with record-replay |
Both have their place. For unit tests, it is important to create minimal mocks and instead rely more on "fakes". Mocks are too brittle. In either case, tests must be very fast and reliable.
Record-replay for integration tests
Testing AI applications end-to-end creates some challenges:
- API costs accumulate quickly during development and CI
- Non-deterministic responses make tests unreliable
- Multiple providers require testing the same logic across different APIs
Our solution: Record real API responses once, replay them for fast, deterministic tests. This is better than mocking because AI APIs have complex response structures and streaming behavior. Mocks can miss edge cases that real APIs exhibit. A single test can exercise underlying APIs in multiple complex ways making it really hard to mock.
This gives you:
- Cost control - No repeated API calls during development
- Speed - Instant test execution with cached responses
- Reliability - Consistent results regardless of external service state
- Provider coverage - Same tests work across OpenAI, Anthropic, local models, etc.
Testing Quick Start
You can run the unit tests with:
uv run --group unit pytest -sv tests/unit/
For running integration tests, you must provide a few things:
-
A stack config. This is a pointer to a stack. You have a few ways to point to a stack:
server:<config>- automatically start a server with the given config (e.g.,server:starter). This provides one-step testing by auto-starting the server if the port is available, or reusing an existing server if already running.server:<config>:<port>- same as above but with a custom port (e.g.,server:starter:8322)- a URL which points to a Llama Stack distribution server
- a distribution name (e.g.,
starter) or a path to arun.yamlfile - a comma-separated list of api=provider pairs, e.g.
inference=fireworks,safety=llama-guard,agents=meta-reference. This is most useful for testing a single API surface.
-
Any API keys you need to use should be set in the environment, or can be passed in with the --env option.
You can run the integration tests in replay mode with:
# Run all tests with existing recordings
uv run --group test \
pytest -sv tests/integration/ --stack-config=starter
Re-recording tests
Local Re-recording (Manual Setup Required)
If you want to re-record tests locally, you can do so with:
LLAMA_STACK_TEST_INFERENCE_MODE=record \
uv run --group test \
pytest -sv tests/integration/ --stack-config=starter -k "<appropriate test name>"
This will record new API responses and overwrite the existing recordings.
You must be careful when re-recording. CI workflows assume a specific setup for running the replay-mode tests. You must re-record the tests in the same way as the CI workflows. This means
- you need Ollama running and serving some specific models.
- you are using the `starter` distribution.
Remote Re-recording (Recommended)
For easier re-recording without local setup, use the automated recording workflow:
# Record tests for specific test subdirectories
./scripts/github/schedule-record-workflow.sh --test-subdirs "agents,inference"
# Record with vision tests enabled
./scripts/github/schedule-record-workflow.sh --test-suite vision
# Record with specific provider
./scripts/github/schedule-record-workflow.sh --test-subdirs "agents" --test-provider vllm
This script:
- 🚀 Runs in GitHub Actions - no local Ollama setup required
- 🔍 Auto-detects your branch and associated PR
- 🍴 Works from forks - handles repository context automatically
- ✅ Commits recordings back to your branch
Prerequisites:
- GitHub CLI:
brew install gh && gh auth login - jq:
brew install jq - Your branch pushed to a remote
Supported providers: vllm, ollama
Next Steps
- Integration Testing Guide - Detailed usage and configuration
- Unit Testing Guide - Fast component testing