OpenCode with MLX

open_code_mlx.md

The following guide will show you how to connect a local model served with MLX to OpenCode for local coding.

1. Install OpenCode

curl -fsSL https://opencode.ai/install | bash

2. Install mlx-lm

pip install mlx-lm

3. Make a custom provider for OpenCode

Open ~/.config/opencode/opencode.json and past the following (if you already have a config just add the MLX provider):

{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "mlx": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "MLX (local)",
      "options": {
        "baseURL": "http://127.0.0.1:8080/v1"
      },
      "models": {
        "mlx-community/NVIDIA-Nemotron-3-Nano-30B-A3B-4bit": {
          "name": "Nemotron 3 Nano"
        }
      }
    }
  }
}

4. Start the mlx-lm server

mlx_lm.server

5. Start OpenCode and select the provider

In the repo you plan to work, type opencode.

Once inside the OpenCode TUI:

1. Enter /connect
2. Type MLX and select it
3. For the API key enter none
4. Select the model
5. Start planning and building

what if already downloaded, how to server from local repo ? (and whit what name ? )
mlx_lm.server --model /Volumes//huggingface/hub/mlx-community/Qwen3.6-35B-A3B-nvfp4/ --host 0.0.0.0 --

---

it's still trying to redownload from huggingface instead of using local folder or searching in another location
/users/.cache/huggingface/hub/models--mlx-community--Qwen3.6-35B-A3B-nvfp4/snapshots/9c1a3a223ddd8a3425212cc421056614f149cf0f
with error Not Found: No safetensors found ; but safetensors are in the provided --model folder

qwen 3.6 -> 35b-a3b + opencode

2026-05-05 15:38:49,121 - INFO - Prompt processing progress: 43835/43836
2026-05-05 15:38:49,287 - INFO - Prompt processing progress: 43836/43836
2026-05-05 15:38:58,984 - INFO - Prompt Cache: 4 sequences, 3.46 GB
2026-05-05 15:38:58,984 - INFO - - assistant: 2 sequences, 1.93 GB
2026-05-05 15:38:58,984 - INFO - - user: 1 sequences, 0.96 GB
2026-05-05 15:38:58,984 - INFO - - system: 1 sequences, 0.57 GB
192.168.1.73 - - [05/May/2026 15:38:58] "POST /v1/chat/completions HTTP/1.1" 200 -
2026-05-05 15:39:00,384 - INFO - Prompt processing progress: 228/229
2026-05-05 15:39:00,433 - INFO - Prompt processing progress: 229/229
2026-05-05 15:39:05,155 - INFO - Prompt Cache: 6 sequences, 5.40 GB
2026-05-05 15:39:05,155 - INFO - - assistant: 4 sequences, 3.87 GB
2026-05-05 15:39:05,155 - INFO - - user: 1 sequences, 0.96 GB
2026-05-05 15:39:05,155 - INFO - - system: 1 sequences, 0.57 GB
192.168.1.73 - - [05/May/2026 15:39:05] "POST /v1/chat/completions HTTP/1.1" 200 -
2026-05-05 15:39:06,142 - INFO - Prompt processing progress: 89/90
libc++abi: terminating due to uncaught exception of type std::runtime_error: [METAL] Command buffer execution failed: Insufficient Memory (00000008:kIOGPUCommandBufferCallbackErrorOutOfMemory)

+> trying workaround with param
--prompt-cache-bytes 8589934592 \

--prompt-cache-size 6
--prompt-concurrency 2
--decode-concurrency 2
--prefill-step-size 1024

+> same crash (dont have that issue with llama.cpp/lmstudio :| )