AI Adapter

A Rust proxy that exposes an OpenAI Responses API interface, translating to various upstream backends (DeepSeek, OpenAI, Anthropic) with full streaming SSE support. Built for Codex CLI and similar tools hardcoded to OpenAI.

Codex / Client          AI Adapter :9090          Upstream
─────────────          ─────────────────          ────────
/v1/responses   ──▶    translate/            ──▶  DeepSeek Chat
(Responses API)        deepseek/chat.rs           (Plan A)

/v1/responses   ──▶    translate/            ──▶  DeepSeek Anthropic
(Responses API)        deepseek/anthropic.rs      (Plan B)

/v1/responses   ──▶    translate/            ──▶  OpenAI Chat
(Responses API)        openai/chat.rs

/v1/responses   ──▶    translate/            ──▶  Anthropic
(Responses API)        anthropic/convert.rs

/v1/responses   ──▶    translate/            ──▶  XiaomiMimo Chat
(Responses API)        xiaomimimo/chat.rs         (+ Anthropic)

Features

• Vendor isolation: src/translate/{deepseek,openai,anthropic}/ — each vendor gets its own module with vendor-specific quirks
• Bidirectional streaming: Full SSE event translation in all directions (Chat ↔ Responses, Anthropic ↔ Responses)
• DeepSeek Plan A/B:
  • Plan A (Chat): thinking: disabled, developer → system role mapping, reasoning cache for multi-turn
  • Plan B (Anthropic): tool_use/tool_result merging, native thinking support
• Reasoning cache: On-disk redb cache at ~/.ai-adapter/state.redb for multi-turn thinking compliance
• Tool calling: Full function call streaming, flat & nested tool format support (get_function())
• Compaction: POST /v1/responses/compact for Codex CLI context management
• Config-driven: YAML/JSON config files, environment variables, CLI flags
• Error dumps: Saves failed exchanges to logs/ with auth redaction
• Structured logging: Human-readable to stderr, JSON to daily-rotated files

Quick Start

# Build
cargo build --release

# Run with inline config
./target/release/ai-adapter \
  --base-url https://api.deepseek.com/anthropic \
  --upstream-format anthropic \
  --apikey sk-your-key \
  --model deepseek-v4-pro

Point Codex at http://127.0.0.1:9090/v1.

Subcommands

# Show version info
./target/release/ai-adapter version

# Print default config template (yaml)
./target/release/ai-adapter config
./target/release/ai-adapter config --format json

# List active sessions (requires running server)
./target/release/ai-adapter session ls

CLI Options

Flag	Env	Default	Description
-c, --config	—	—	Config file (YAML/JSON)
--base-url	UPSTREAM_BASE_URL	—	Upstream API base URL
--upstream-format	UPSTREAM_FORMAT	openai-chat	anthropic, openai-chat, responses
--vendor	—	auto	deepseek, openai, anthropic, xiaomimimo, auto
--apikey	UPSTREAM_API_KEY	—	Upstream API key
--prefer-client-key	—	false	Prefer Authorization header over config key
--model	UPSTREAM_MODEL	—	Default model override
-a, --addr	ADDR	0.0.0.0:9090	Server listen address
--log-level	RUST_LOG	info	trace, debug, info, warn, error
--log-dir	LOG_DIR	$DATA_DIR/logs	JSON app log directory (daily rotated)
--logtostderr	LOGTOSTDERROR	true	Log to stderr (set false for file-only)
--alsologtostderr	ALSOLOGTOSTDERROR	false	Also log to stderr when file logging active
--access-log	—	false	Enable HTTP access log (JSON lines)
--access-log-dir	ACCESS_LOG_DIR	$LOG_DIR	Access log directory (defaults to LOG_DIR)
--drop-images	—	false	Strip images from requests
--no-cors	—	false	Disable CORS headers
—	TRUNCATE_REASONING	false	Truncate reasoning content >32KB when enabled

API Endpoints

Endpoint	Method	Description
/v1/chat/completions	POST	Chat → upstream Responses
/v1/responses	POST	Responses → upstream Chat/Anthropic
/v1/responses/compact	POST	Context compaction for Codex CLI
/v1/models	GET	Pass-through
/v1/*	*	Catch-all pass-through
/__/session	GET	List active sessions (JSON)
/health	GET	Health check

Vendor Behavior

Vendor	Protocol	thinking	developer role	tool format	Special handling
DeepSeek	Chat	disabled	→ system	flat	reasoning cache, reasoning_tokens=0
DeepSeek	Anthropic	disabled	→ assistant	nested	tool_use/tool_result merge
OpenAI	Chat	N/A	preserved	nested	standard
Anthropic	Anthropic	N/A	→ assistant	nested	standard
XiaomiMimo	Chat	none	→ system	flat	api-key auth, tp-/sk- keys, token-plan support
XiaomiMimo	Anthropic	none	→ assistant	nested	shared sanitization with DeepSeek

Stream Event Mapping

Chat SSE → Responses SSE

Chat chunk	Responses event
First chunk	response.created + output_item.added + content_part.added
delta.content	response.output_text.delta
delta.tool_calls (new)	response.output_item.added (function_call)
delta.tool_calls (subsequent)	response.function_call_arguments.delta
finish_reason / [DONE]	output_text.done → content_part.done → output_item.done → response.completed

Anthropic SSE → Responses SSE

Anthropic event	Responses event
message_start	response.created + response.in_progress
content_block_start (text)	output_item.added + content_part.added
content_block_start (tool_use)	output_item.added (function_call)
content_block_delta.text_delta	output_text.delta
content_block_delta.input_json_delta	function_call_arguments.delta
content_block_stop	output_item.done
message_stop	response.completed

Usage Examples

curl test

curl http://localhost:9090/v1/responses \
  -H "Content-Type: application/json" \
  -d '{
    "model": "deepseek-v4-pro",
    "input": [{"type": "message", "role": "user", "content": [{"type": "input_text", "text": "Hello!"}]}],
    "stream": true
  }'

Docker

Use the pre-built image from Docker Hub:

docker run -d -p 9090:9090 \
  -v ai-adapter-data:/data \
  -e UPSTREAM_BASE_URL=https://api.deepseek.com/anthropic \
  -e UPSTREAM_FORMAT=anthropic \
  -e UPSTREAM_API_KEY=sk-xxx \
  dyrnq/ai-adapter

Build Options

Dockerfile	Use case
Dockerfile	Local build with cargo build inside
Dockerfile.static	CI release — copies pre-built binary

Volume / Environment

Volume / Env	Description
/data (volume)	Persistent data: state DB and logs
DATA_DIR	Data directory (default /data)
ADDR	Listen address (default 0.0.0.0:9090)
LOGTOSTDERROR	Log to stderr (default true)
ALSOLOGTOSTDERROR	Also log to stderr when file logging on
LOG_DIR	App log directory (default $DATA_DIR/logs)
ACCESS_LOG_DIR	HTTP access log directory (default $LOG_DIR)

License

MIT