obsidian/wiki/claude-code/lmstudio-rest-api.md

title	aliases	tags	sources	created	updated
LM Studio REST API (v1)	lmstudio-api lm-studio-rest lmstudio-v1	lmstudio rest-api local-inference openai-compat anthropic-compat mcp	raw/LM Studio API.md	2026-04-30	2026-04-30

LM Studio REST API (v1)

LM Studio 0.4.0 introduced the native v1 REST API at /api/v1/*. It sits alongside OpenAI-compatible and Anthropic-compatible endpoints and offers the richest feature set for local inference.

v1 vs v0

The old v0 API (/api/v0/*) is superseded. Migrate to /api/v1/* for:

• Stateful chats — server keeps conversation context across turns
• MCP via API — use MCPs configured in LM Studio directly from requests
• Authentication — API token support
• Model management — download, load, unload via API

Supported Endpoints

Endpoint	Method	Purpose
/api/v1/chat	POST	Inference (native)
/api/v1/models	GET	List loaded models
/api/v1/models/load	POST	Load a model into VRAM
/api/v1/models/unload	POST	Unload a model
/api/v1/models/download	POST	Download a model
/api/v1/models/download/status	GET	Poll download progress

Inference Endpoint Comparison

Four endpoints can run inference. Pick based on which features you need:

Feature	/api/v1/chat	/v1/responses (OAI)	/v1/chat/completions (OAI)	/v1/messages (Anthropic)
Streaming	✅	✅	✅	✅
Stateful chat	✅	✅	❌	❌
Remote MCPs	✅	✅	❌	❌
LM Studio MCPs	✅	✅	❌	❌
Custom tools	❌	✅	✅	✅
Assistant messages in request	❌	✅	✅	✅
Model load streaming events	✅	❌	❌	❌
Prompt processing events	✅	❌	❌	❌
Specify context length	✅	❌	❌	❌

Decision guide:

• Need MCP tools + stateful chat → /api/v1/chat or /v1/responses
• Need custom tool definitions → /v1/responses, /v1/chat/completions, or /v1/messages
• Dropping in existing OpenAI SDK code → /v1/chat/completions
• Dropping in existing Anthropic SDK code → /v1/messages

Key Takeaways

• The native /api/v1/chat endpoint has exclusive features: stateful chat, LM Studio MCPs, model-load events, prompt-processing events, and per-request context length.
• /v1/responses (OpenAI Responses API compat) is the best of both worlds — stateful + MCP + custom tools.
• /v1/chat/completions is the broadest drop-in for existing OpenAI code but loses statefulness and MCP.
• /v1/messages lets you redirect the Anthropic SDK to a local model with minimal code change (see wiki/claude-code/lmstudio-anthropic-compat).
• Model management endpoints let you fully automate the model lifecycle — download → load → infer → unload — without touching the GUI.
• API token auth is available for securing the local server (useful when exposed on a LAN).

Related Articles

• wiki/claude-code/lmstudio-anthropic-compat — redirect Claude Code / Anthropic SDK to LM Studio via env vars
• wiki/claude-code/lmstudio-chat-completions — OpenAI /v1/chat/completions usage, params, debugging
• wiki/claude-code/lmstudio-embeddings — /v1/embeddings for local RAG pipelines
• wiki/claude-code/lmstudio-idle-ttl-auto-evict — memory management: TTL and auto-evict
• wiki/agent-sdk/overview — build multi-agent systems that call local models

Sources

• raw/LM Studio API.md — clipped from lmstudio.ai/docs/developer/rest