Other APIs Overview

This page is a navigation overview for text, model, compatibility, and dedicated routing APIs. Full parameters, examples, and errors are split into individual pages.

Text and Model APIs

Use case	Documentation	Endpoint
Anthropic Messages / Claude Code	Messages	POST /v1/messages
Token Count	Messages	POST /v1/messages/count_tokens
OpenAI Responses / Codex CLI	Responses	POST /v1/responses
OpenAI Chat Completions	Chat Completions	POST /v1/chat/completions
Model list	Models	GET /v1/models
Usage and billing	Usage and Billing	GET /v1/usage

Compatibility and Dedicated Paths

Use case	Documentation	Endpoint
Clients without /v1 prefix	Aliases	/responses, /chat/completions, /images...
Codex-compatible entry	Aliases	/backend-api/codex/responses
Force the Antigravity account pool	Antigravity	/antigravity/...

Platform Restrictions

• Image APIs are scoped by key type and protocol: OpenAI synchronous image endpoints require a general OpenAI group; Gemini native paths require a general Gemini group; async image tasks require an image API key bound to an image batch group. See Image APIs Overview.
• Gemini native text, multimodal, and image calls use /v1beta/models....
• OpenAI groups do not support POST /v1/messages/count_tokens.
• The current backend does not register /models or /usage aliases without /v1.