API Changelog

👾 LM Studio 0.3.15 • 2025-04-24

Improved Tool Use API Support

OpenAI-like REST API now supports the tool_choice parameter:

{
  "tool_choice": "auto" // or "none", "required"
}

"tool_choice": "none" — Model will not call tools
"tool_choice": "auto" — Model decides
"tool_choice": "required" — Model must call tools (llama.cpp only)

Chunked responses now set "finish_reason": "tool_calls" when appropriate.

👾 LM Studio 0.3.14 • 2025-03-27

[API/SDK] Preset Support

RESTful API and SDKs support specifying presets in requests.

(example needed)

👾 LM Studio 0.3.10 • 2025-02-18

Speculative Decoding API

Enable speculative decoding in API requests with "draft_model":

{
  "model": "deepseek-r1-distill-qwen-7b",
  "draft_model": "deepseek-r1-distill-qwen-0.5b",
  "messages": [ ... ]
}

Responses now include a stats object for speculative decoding:

"stats": {
  "tokens_per_second": ...,
  "draft_model": "...",
  "total_draft_tokens_count": ...,
  "accepted_draft_tokens_count": ...,
  "rejected_draft_tokens_count": ...,
  "ignored_draft_tokens_count": ...
}

👾 LM Studio 0.3.9 • 2025-01-30

Idle TTL and Auto Evict

Set a TTL (in seconds) for models loaded via API requests (docs article: Idle TTL and Auto-Evict)

curl http://localhost:1234/api/v0/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "deepseek-r1-distill-qwen-7b",
    "messages": [ ... ]
+   "ttl": 300,
}'

With lms:

lms load --ttl <seconds>

Separate `reasoning_content` in Chat Completion responses

For DeepSeek R1 models, get reasoning content in a separate field. See more here.

Turn this on in App Settings > Developer.

👾 LM Studio 0.3.6 • 2025-01-06

Tool and Function Calling API

Use any LLM that supports Tool Use and Function Calling through the OpenAI-like API.

Docs: Tool Use and Function Calling.

👾 LM Studio 0.3.5 • 2024-10-22

Introducing `lms get`: download models from the terminal

You can now download models directly from the terminal using a keyword

lms get deepseek-r1

or a full Hugging Face URL

lms get <hugging face url>

To filter for MLX models only, add --mlx to the command.

lms get deepseek-r1 --mlx