unsloth/studio/backend/models
Roland Tannous 587a84d7d3
Studio: add Anthropic-compatible /v1/messages endpoint (#4981)
* Add Anthropic-compatible /v1/messages endpoint with tool support

Translate Anthropic Messages API format to/from internal OpenAI format
and reuse the existing server-side agentic tool loop. Supports streaming
SSE (message_start, content_block_delta, etc.) and non-streaming JSON.
Includes offline unit tests and e2e tests in test_studio_run.py.

* Add enable_tools, enabled_tools, session_id to /v1/messages endpoint

Support the same shorthand as /v1/chat/completions: enable_tools=true
with an optional enabled_tools list uses built-in server tools without
requiring full Anthropic tool definitions. session_id is passed through
for sandbox isolation. max_tokens is now optional.

* Strip leaked tool-call XML from Anthropic endpoint content

Apply _TOOL_XML_RE to content events in both streaming and
non-streaming tool paths, matching the OpenAI endpoint behavior.

* Emit custom tool_result SSE event in Anthropic stream

Adds a non-standard tool_result event between the tool_use block close
and the next text block, so clients can see server-side tool execution
results. Anthropic SDKs ignore unknown event types.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Split /v1/messages into server-side and client-side tool paths

enable_tools=true runs the existing server-side agentic loop with
built-in tools (web_search/python/terminal). A bare tools=[...] field
now triggers a client-side pass-through: client-provided tools are
forwarded to llama-server and any tool_use output is returned to the
caller with stop_reason=tool_use for client execution.

This fixes Claude Code (and any Anthropic SDK client) which sends
tools=[...] expecting client-side execution but was previously routed
through execute_tool() and failing with 'Unknown tool'.

Adds AnthropicPassthroughEmitter to convert llama-server OpenAI SSE
chunks into Anthropic SSE events, plus unit tests covering text
blocks, tool_use blocks, mixed, stop reasons, and usage.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Fix httpcore GeneratorExit in /v1/messages passthrough stream

Explicitly aclose aiter_lines() before the surrounding async with
blocks unwind, mirroring the prior fix in external_provider.py
(a41160d3) and cc757b78's RuntimeError suppression.

* Wire stop_sequences through /v1/messages; warn on tool_choice

Plumb payload.stop_sequences to all three code paths (server-side
tool loop, no-tool plain, client-side passthrough) so Anthropic SDK
clients setting stop_sequences get the behavior they expect. The
llama_cpp backend already accepted `stop` on both generate_chat_
completion and generate_chat_completion_with_tools; the Anthropic
handler simply wasn't passing it.

tool_choice remains declared on the request model for Anthropic SDK
compatibility (the SDK often sets it by default) but is not yet
honored. Log a structured warning on each request carrying a non-
null tool_choice so the silent drop is visible to operators.

* Wire min_p / repetition_penalty / presence_penalty through /v1/messages

Align the Anthropic endpoint's sampling surface with /v1/chat/completions.
Adds the three fields as x-unsloth extensions on AnthropicMessagesRequest
and threads them through all three code paths: server-side tool loop,
no-tool plain, and client-side passthrough.

The passthrough builder emits "repeat_penalty" (not "repetition_penalty")
because that is llama-server's field name; the backend methods already
apply the same rename internally.

* Fix block ordering and prev_text reset in non-streaming tool path

_anthropic_tool_non_streaming was building the response by appending
all tool_use blocks first, then a single concatenated text block at
the end — losing generation order and merging pre-tool and post-tool
text into one block. It also never reset prev_text between synthesis
turns, so the first N characters of each post-tool turn were dropped
(where N = length of the prior turn's final cumulative text).

Rewrite to build content_blocks incrementally in generation order,
matching the streaming emitter's behavior: deltas within a turn are
merged into the trailing text block, tool_use blocks interrupt the
text sequence, and prev_text is reset on tool_end so turn N+1 diffs
against an empty baseline.

Caught by gemini-code-assist[bot] review on #4981.

* Make test_studio_run.py e2e tests pytest-compatible

Add a hybrid session-scoped studio_server fixture in conftest.py that
feeds base_url / api_key into the existing e2e test functions. Three
invocation modes are now supported:

1. Script mode (unchanged) — python tests/test_studio_run.py
2. Pytest + external server — point at a running instance via
   UNSLOTH_E2E_BASE_URL / UNSLOTH_E2E_API_KEY env vars, no per-run
   GGUF load cost
3. Pytest + fixture-managed server — pytest drives _start_server /
   _kill_server itself via --unsloth-model / --unsloth-gguf-variant,
   CI-friendly

The existing _start_server / _kill_server helpers and main() stay
untouched so the script entry point keeps working exactly as before.
Test function signatures are unchanged — the (base_url, api_key)
parameters now resolve via the new fixtures when running under
pytest.

* Rename test_studio_run.py -> test_studio_api.py

The file is entirely about HTTP API endpoint testing (OpenAI-compatible
/v1/chat/completions, Anthropic-compatible /v1/messages, API key auth,
plus a CLI --help sanity check on the command that runs the API). None
of its tests cover training, export, chat-UI, or internal-Python-API
concerns.

The old name misleadingly suggested "tests for the unsloth studio run
CLI subcommand" — the new name reflects the actual scope.

Updates:
- git mv the file (rename tracked, history preserved)
- Rewrite opening docstring to state the API surface focus and call
  out what is explicitly out of scope
- Update all 4 Usage-block path references to the new filename
- LOG_FILE renamed to test_studio_api.log
- conftest.py fixture import rewritten from test_studio_run to
  test_studio_api, plus 7 docstring/comment references updated

No functional changes to test logic, signatures, or main().

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
2026-04-13 11:07:42 +04:00
..
.gitkeep fix: restore models directory files deleted during restructure 2026-02-02 19:36:30 +00:00
__init__.py feat(studio): training history persistence and past runs viewer (#4501) 2026-03-25 00:58:55 -07:00
auth.py [pre-commit.ci] auto fixes from pre-commit.com hooks 2026-04-10 13:33:51 +00:00
data_recipe.py feat(studio): multi-file unstructured seed upload with better backend extraction (#4468) 2026-03-20 13:22:42 -07:00
datasets.py Final cleanup 2026-03-12 18:28:04 +00:00
export.py Final cleanup 2026-03-12 18:28:04 +00:00
inference.py Studio: add Anthropic-compatible /v1/messages endpoint (#4981) 2026-04-13 11:07:42 +04:00
models.py feat: custom scan folders for GGUF model discovery (#4723) 2026-03-31 06:40:31 -07:00
responses.py Final cleanup 2026-03-12 18:28:04 +00:00
training.py fix(studio): correct default weight_decay and learning rate (#4695) 2026-03-31 13:50:25 +04:00
users.py fix: remove old comments (#4292) 2026-03-14 16:50:13 +04:00