fix: model discovery, fallback IDs, and conversation context persistence#19
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ephraimduncan merged 1 commit intomainfrom Mar 22, 2026
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Three compounding bugs prevented non-composer models from working and caused context loss when switching models or restarting the proxy. Model discovery (h2-bridge.mjs): - callCursorUnaryRpc used streaming mode (application/connect+proto with Connect framing) for the GetUsableModels unary RPC. Cursor expects application/proto with a raw protobuf body. Add unary config flag that switches content-type and writes a single body instead of streaming. Fallback model IDs (models.ts): - Nearly every non-composer ID was wrong: claude-4.6-opus (real: claude-4.6-opus-high), gpt-5.4 (real: gpt-5.4-medium), grok-4.20 (doesn't exist). Corrected against Oh My Pi's maintained registry. Conversation context (proxy.ts): - Split single bridgeKey into two: bridgeKey (model-specific, for active tool-call bridges) and convKey (model-independent, for conversation state). Context now survives model switches within a session. - Make conversationId deterministic from convKey hash instead of crypto.randomUUID(). Same first user message produces the same UUID, so Cursor's server-side conversation persists across proxy restarts.
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Three compounding bugs prevented non-composer models from working and caused context loss when switching models or restarting the proxy.
Model discovery (h2-bridge.mjs)
callCursorUnaryRpcused streaming mode (application/connect+protowith Connect framing) for theGetUsableModelsunary RPC. Cursor expectsapplication/protowith a raw protobuf body for unary calls. Discovery silently failed, falling back to hardcoded models.Fix: Add
unaryconfig flag to the H2 bridge that switches content-type and writes a single body instead of streaming.Fallback model IDs (models.ts)
Nearly every non-composer fallback ID was wrong:
claude-4.6-opus(real:claude-4.6-opus-high),gpt-5.4(real:gpt-5.4-medium),grok-4.20(doesn't exist). Onlycomposer-2/composer-2-fasthappened to be valid.Fix: Corrected all IDs against Oh My Pi's maintained model registry.
Conversation context (proxy.ts)
Two issues:
Context lost on model switch: A single
bridgeKey(model-specific) was used for both active tool-call bridges and conversation state. Switching models changed the key, creating a newconversationIdwith no history.Context lost on proxy restart:
conversationIdwascrypto.randomUUID()— ephemeral. After restart, the in-memory map was empty and a new random ID was generated. Cursor's server couldn't match it to the existing conversation.Fix:
bridgeKey(model-specific, foractiveBridges) andconvKey(model-independent, forconversationStates)conversationIddeterministically fromconvKeyhash so Cursor's server-side conversation persists across restartsFixes #17