Compatibility matrix

This matrix reflects **implemented** gateway behavior for dialect × modality × provider kind.

Last updated: 2026-07-19
Owning tests: proxy/*_test.go, config/capability_test.go (hermetic; no live vendor calls in CI)

This matrix reflects implemented gateway behavior for dialect × modality × provider kind. It is not a live vendor certification.

Legend

Symbol	Meaning
P	Native passthrough (same family wire; model rewrite + auth + metering)
T	Translated via canonical IR
U	Unsupported (fail closed with dialect-shaped 4xx; no upstream call when capability off)
—	Not applicable / no ingress for that dialect×modality yet
opt	`openai_compat` requires explicit `capabilities.<modality>: true`

Text chat

Ingress dialect	Route	`openai`	`openai_compat`	`anthropic`	`google`
OpenAI	`POST /v1/chat/completions`	P	P	T	T
Anthropic	`POST /v1/messages`	T	T	P	T
Google	`POST /v1beta/models/{m}:generateContent` (+ stream)	T	T	T	P

Also: POST /v1/messages/count_tokens (Anthropic proxy or estimate).

Image generation

Ingress	Route	`openai`	`openai_compat`	`anthropic`	`google`
OpenAI	`POST /v1/images/generations` (+ edits/variations)	P	P (opt)	U	U*
Anthropic-gateway	`POST /v1/images` (planned Media Contract v1)	—	—	—	—
Google	`:generateImages` / Imagen (planned)	—	—	—	—

*Native Gemini image-in-chat uses generateContent multimodal, not /v1/images/*.
OpenAI-compat hosts (OpenRouter, xAI Imagine, etc.) need capabilities.image_gen: true.

Video generation

Ingress	Route	`openai`	`openai_compat`	`anthropic`	`google`
OpenAI	`POST /v1/videos`, `GET /v1/videos/{id}`	P	P (opt)	U	U
Google LRO	planned	—	—	—	—

Audio (HTTP)

Ingress	Route	`openai`	`openai_compat`	`anthropic`	`google`
OpenAI TTS	`POST /v1/audio/speech`	P	P (opt)	U	T (→ generateContent AUDIO)
OpenAI STT	`POST /v1/audio/transcriptions`, `/translations`	P	P (opt)	U	U
Anthropic-gateway TTS	`POST /v1/audio/speech` + `anthropic-version`	T	T (opt)	U	T
Anthropic-gateway STT	`POST /v1/audio/transcriptions` (+ translations) + `anthropic-version`	T	T (opt)	U	U
Google TTS	`POST /v1beta/models/{m}:generateSpeech`	T (wrap binary)	T (opt)	U	T (→ generateContent AUDIO)

Fidelity: same-family TTS body + multipart STT are byte-passthrough; translation uses base64 wrap/unwrap only (no codec re-encode). Multipart limit 32 MiB.

Operator note (Groq STT-first): configure groq with capabilities.audio_transcribe: true and call model: groq/<whisper-model> (or alias whisper-fast) while leaving defaults.openai_dialect on another chat provider. Full guide: Groq STT.

Prompt caching (#108)

Ingress → Egress	Behavior
Anthropic → Anthropic	P / T preserve `cache_control` breakpoints
OpenAI → OpenAI	P (body) / T preserve `prompt_cache_key` / `prompt_cache_retention`
Google → Google	P / T preserve `cachedContent` resource name
Cross-family	Drop foreign cache directives (no illegal wire fields)
OpenAI/Google → Anthropic + `caching.auto_breakpoints.enabled`	Opt-in inject `cache_control` on system/tools (client wins; see Prompt caching)

Usage: cache read/write tokens map when upstream reports them (all dialects).

Conversations (OpenAI stateful threads)

Ingress	Route	All provider kinds
OpenAI	`/v1/conversations*` (nested included)	U — HTTP 501 `not_implemented` (stateless; no gateway store). Prefer Responses + client state / Files. Decision: Conversations (Option A).

Realtime (WebSocket)

Ingress	`openai`	`openai_compat`	`anthropic`	`google`
OpenAI `/v1/realtime`	P (passthrough)	P (opt-in `realtime`)	U (no Anthropic WS)	U fail-closed `unsupported_realtime_bridge`
Google Live	U fail-closed `unsupported_realtime_bridge`	U same	U	P (passthrough)

Bridge: OpenAI Realtime ↔ Google Live IR bridge is not implemented (deferred). Clients must use the native protocol URL for each provider family.

Capability defaults by kind

Kind	text	image_gen	video_gen	audio_*	realtime
`openai`	on	on	on	on	on
`google`	on	on	on	on	on
`anthropic`	on	off	off	off	off
`openai_compat`	on	off	off	off	off

CI enforcement

Default CI: go test ./... -race air-gapped (httptest fakes only).
No -tags live in default workflows.
Capability matrix e2e cells expand as M4 modalities land (proxy package).

SDK hermetic strategy

Official SDK wire coverage (headers, happy paths, no live keys): SDK matrix.

Named hermetic anchors: proxy.TestNonStreamPassthrough (OpenAI), proxy.TestAnthropicStreamPassthrough (Anthropic), proxy.TestGooglePassthroughStreamAndErrors (Google).