Use OpenCode with Docker Model Runner

This guide shows how to connect OpenCode to Docker Model Runner so OpenCode can
use local models for coding tasks. You'll configure an 
opencode.json file,
verify the API endpoint, and run OpenCode against models served from your local
Docker environment.
Acknowledgment
Docker would like to thank Pradumna Saraf for his contribution to this guide.
Unlike the OpenCode sandbox guide,
this guide focuses on using OpenCode as a local coding tool backed by Docker
Model Runner rather than running OpenCode in a containerized sandbox.
In this guide, you'll learn how to:
Pull coding models for OpenCode
Configure OpenCode to use Docker Model Runner
Verify the local API endpoint and start OpenCode
Package 
gpt-oss with a larger context window when you need it
Prerequisites
Before you start, make sure you have:
Docker Desktop or Docker Engine installed
Docker Model Runner enabled
OpenCode installed
If you use Docker Desktop, turn on TCP access in Settings > AI, or run:
$ docker desktop enable model-runner --tcp 12434
Step 1: Pull a coding model
Pull one or more models before you configure OpenCode:
$ docker model pull ai/qwen3-coder
$ docker model pull ai/devstral-small-2
These models are a good fit for coding workflows because they support large
context windows.
Step 2: Create an OpenCode configuration
OpenCode reads configuration from either of these locations:
~/.config/opencode/opencode.json for a global setup
opencode.json in your project root for a project-specific setup
Project-level configuration overrides the global file.
Add a provider that points to Docker Model Runner:
{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "dmr": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "Docker Model Runner",
      "options": {
        "baseURL": "http://localhost:12434/v1"
      },
      "models": {
        "qwen3-coder": {
          "name": "ai/qwen3-coder"
        },
        "devstral-small-2": {
          "name": "ai/devstral-small-2"
        }
      }
    }
  }
}
This configuration adds Docker Model Runner as an OpenCode provider and exposes
two local models.
[!NOTE]
If your setup expects the older OpenAI-compatible path, use
http://localhost:12434/engines/v1 instead.
Step 3: Verify the endpoint
Check that Docker Model Runner is reachable before you open OpenCode:
$ curl http://localhost:12434/v1/models
If you use the older path, run:
$ curl http://localhost:12434/engines/v1/models
The response should list the models available through Docker Model Runner.
Step 4: Start OpenCode
From your project directory, run:
$ opencode
To switch models from the TUI, run:
/models
Then select the model from the 
dmr provider.
Step 5: Package 
gpt-oss with a larger context window
This step is optional. Use it if you need a larger context window for
repository-scale tasks.
gpt-oss defaults to a smaller context window than coding-focused models. If
you want to use it for repository-scale tasks, package a larger variant:
$ docker model pull ai/gpt-oss
$ docker model package --from ai/gpt-oss --context-size 128000 gpt-oss:128k
Then add it to your OpenCode configuration:
{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "dmr": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "Docker Model Runner",
      "options": {
        "baseURL": "http://localhost:12434/v1"
      },
      "models": {
        "gpt-oss:128k": {
          "name": "gpt-oss:128k"
        }
      }
    }
  }
}
Troubleshooting
If OpenCode can't connect, check Docker Model Runner status:
$ docker model status
If OpenCode does not show your model, list local models:
$ docker model ls
If the model is missing, pull it first and confirm the model name in
opencode.json matches the local model you want to use.
Learn more
Docker Model Runner overview
Docker Model Runner API reference
IDE and tool integrations