sbx/claude-model-runner-kit repository overview

⁠claude-model-runner

A mixin that points the built-in claude agent at a local Docker Model Runner⁠ instance via its Anthropic-compatible endpoint. Useful for offline development, cost-free experimentation, or testing custom local models with Claude Code.

⁠Usage

sbx run --kit "docker.io/sbx/claude-model-runner-kit:latest" claude ~/my-project

Or from a git URL or a local clone of this repo:

sbx run --kit "git+https://github.com/docker/sbx-kits-contrib.git#dir=claude-model-runner" claude ~/my-project
sbx run --kit ./claude-model-runner/ claude ~/my-project

The agent name passed to sbx run (claude) is the base agent the mixin extends.

The default model is gpt-oss; Claude Code boots into it without any --model argument. To switch models, save spec.yaml to a local directory, change the anchored value at &model "gpt-oss", and pass --kit at that path:

mkdir claude-model-runner
curl -o claude-model-runner/spec.yaml \
    https://raw.githubusercontent.com/docker/sbx-kits-contrib/main/claude-model-runner/spec.yaml
# edit `&model "gpt-oss"` in claude-model-runner/spec.yaml
sbx run --kit ./claude-model-runner claude ~/my-project

For a larger context window than the default, package a variant first:

docker model package --from gpt-oss --context-size 32000 gpt-oss:32k

then point the anchored value at gpt-oss:32k.

⁠How it works

The mixin sets ANTHROPIC_BASE_URL to http://host.docker.internal:12434, so Claude Code's Anthropic-shaped requests reach Docker Model Runner instead of api.anthropic.com. It also pins every Claude Code model alias (ANTHROPIC_DEFAULT_OPUS_MODEL, ANTHROPIC_DEFAULT_SONNET_MODEL, ANTHROPIC_DEFAULT_HAIKU_MODEL, CLAUDE_CODE_SUBAGENT_MODEL) to the same local model via a single YAML anchor, so the default Sonnet/Opus/Haiku/sub-agent picks all land on whatever you've pulled into Model Runner.

⁠Related

• Docker Model Runner⁠
• Run Claude Code locally with Docker Model Runner⁠, the inspiration for this kit