Adds src/mock_provider/, a standalone ASGI app that lets Honcho run with no
model provider, no API key, and no spend. It answers /v1/chat/completions and
/v1/embeddings with obviously-synthetic content derived from the request, so
the same request always produces the same response.
It runs as its own service from the standard Honcho image with a different
entrypoint, the way api and deriver already differ, so there is no second image
to build or keep in digest-sync. The app imports nothing from src.config or
src.db, so it boots even when the rest of the stack is misconfigured.
The chat endpoint generates from the JSON Schema it is sent rather than
answering with prose. That matters because a prose answer does not fail loudly:
repair_response_model_json swallows the parse error and returns an empty
PromptRepresentation, which reads as "the deriver found nothing" rather than
"the mock is wrong". Generation resolves $ref/$defs indirection, caps recursion
for reasoning-tree schemas, and covers json_object mode by recovering the
schema Honcho injects into the prompt. Embeddings are hash-derived, so
identical input yields an identical vector.
Tests drive the production OpenAIBackend and _EmbeddingClient against the app
over ASGI, including the strict json_schema transform that
chat.completions.parse() applies. Verified end to end against a real stack:
messages in, conclusions and 1536-dim embeddings written to pgvector, with no
calls to any real provider.
Mock embeddings carry no semantic similarity, so recall against this provider
must use lexical search. CONTRIBUTING notes that, and the load_dotenv(override=
True) behaviour that lets a stale repo .env win over exported environment
variables.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>