9router/open-sse/AGENTS.md

open-sse

Provider-agnostic SSE engine: one OpenAI-style request → any provider (LLM chat, image, embedding, tts, stt, search), streamed back in the client's format.

Request lifecycle (chat)

handlers/chatCore.js → services/model.js parseModel (resolve provider/model) → executors/index.js getExecutor(provider) → translator/index.js translateRequest (client format → provider format) → executor.execute() (streams upstream) → translateResponse (provider chunks → client format) → SSE out.

Directory map

• config/ — ALL constants/config (no hardcode elsewhere). providers.js/registry/ (provider defs), providerModels.js (alias→models matrix), runtimeConfig.js (timeouts, token limits), *Constants.js.
• translator/ — format conversion. request/<from>-to-<to>.js, response/<from>-to-<to>.js, schema/ (enums: ROLE, CLAUDE_BLOCK…), concerns/ (shared logic), formats/ (per-format). See tests/translator/AGENTS.md.
• executors/ — per-provider upstream call. base.js (BaseExecutor), one file per special provider, index.js map.
• providers/ — registry build + capabilities.js + pricing.js. Entry: index.js (PROVIDERS).
• handlers/ — per-modality cores (chat/image/embedding/tts/stt/search) + sub-provider folders.
• services/ — tokenRefresh/, usage/, combo.js, accountFallback.js, model.js.
• utils/ — streamHandler, error, sessionManager, claudeCloaking.

Conventions

• Config-driven, DRY, camelCase. NEVER hardcode values, models, or block/role strings — use config/ + schema/ constants.
• Translator pipeline pivots through OpenAI as the intermediate format. A translator registered on the exact source:target pair (e.g. claude:kiro) runs as a direct route, skipping the lossy double-hop.
• Translators self-register via register(from, to, reqFn, resFn) as an import side-effect — new files MUST be imported in translator/index.js.

How to add

• Provider: copy providers/REGISTRY_TEMPLATE.js → providers/registry/{id}.js; add models to config/providerModels.js. Generic providers need no executor (DefaultExecutor handles OpenAI-compatible APIs).
• Executor (only for non-standard upstream): subclass BaseExecutor (override getBaseUrls/buildHeaders/buildUrl/execute), register in executors/index.js map. getExecutor falls back to DefaultExecutor when absent.
• Translator: add request|response/<from>-to-<to>.js calling register(...), then import it in translator/index.js. Reuse schema/ + concerns/ — don't re-implement parsing.

Pitfalls

• OpenAI bridge is lossy (thinking, non-base64 images, tool ids, is_error) — prefer a direct route for fragile pairs.
• registry/index.js is an auto-generated static import list; regenerate it (don't hand-edit) after adding a registry/{id}.js. REGISTRY_TEMPLATE is excluded by design.
• Special binary/protobuf formats (kiro EventStream, cursor protobuf, commandcode NDJSON) don't round-trip through OpenAI — handle in their executor.