Example organization overlay for Centaur.

Package your tools, workflows, skills, and sandbox guidance as a reusable overlay image.

Use This Template • What You Customize • Build • Verify

Overview

centaur-darkmatter is a public, forkable template for creating an organization overlay for Centaur. It is intentionally small and free of private data. Use it as the starting point for shipping org-specific capabilities without forking the core platform.

The overlay image is copied into Centaur at runtime:

centaur-darkmatter repo
    |
    v
overlay image
    |
    +-- /app/overlay/org in the API
    +-- /home/agent/overlay/org in sandbox pods

Use This Template

1. Click Use this template in GitHub, or fork the repo if you want to keep a visible upstream relationship.
2. Rename darkmatter examples to your organization or team name.
3. Replace the toy CRM tool with one small real integration.
4. Update the sandbox prompt and skill to match the behavior your agents should follow.
5. Build and publish the overlay image, then point your Centaur Helm values at that image.

Keep credentials out of this repository. Tools should request secrets through Centaur's secret system instead of committing values or .env files.

What You Customize

The template demonstrates the extension points an organization normally owns:

• tools/ for API-discovered tools
• workflows/ for durable workflows
• .agents/skills/ for sandbox-loaded skills
• services/sandbox/SYSTEM_PROMPT.md for organization-specific agent guidance

Repository Map

.
├── .agents/skills/darkmatter-support/     # sandbox skill loaded with the overlay
├── services/sandbox/SYSTEM_PROMPT.md
├── tools/darkmatter_crm/                  # packaged Python CLI tool with sample data
├── tools/darkmatter_go/                   # minimal Go CLI tool
├── tools/darkmatter_rust/                 # minimal Rust CLI tool
├── workflows/daily_darkmatter_brief.py    # example durable workflow
├── tests/
└── Dockerfile                       # copies the overlay to /overlay

Build the overlay image

docker build -t ghcr.io/<org>/<overlay-repo>:local .

The image copies this repository to /overlay. Centaur's Helm chart mounts that path at /app/overlay/org in the API and /home/agent/overlay/org in sandbox pods.

Use with Helm

overlay:
  image:
    repository: ghcr.io/<org>/<overlay-repo>
    tag: sha-0000000
    pullPolicy: IfNotPresent
    sourcePath: /overlay

For the full GitOps example, pair this repo with centaur-darkmatter-infra.

Included examples

tools/darkmatter_crm is a packaged Python CLI tool with no external credentials. tools/darkmatter_rust and tools/darkmatter_go are tiny compiled CLI examples that prove an overlay can ship source-built tools across the supported runtimes.

workflows/daily_darkmatter_brief.py is a minimal recurring workflow that asks an agent for a daily operating summary.

.agents/skills/darkmatter-support/SKILL.md is a sandbox skill that demonstrates how darkmatter-specific playbooks are packaged.

services/sandbox/SYSTEM_PROMPT.md is appended to the base sandbox prompt when the overlay is mounted.

Verify in a running deployment

From the API pod:

echo "$TOOL_DIRS"
echo "$WORKFLOW_DIRS"
ls -la /app/overlay/org

From a sandbox:

echo "$CENTAUR_OVERLAY_DIR"
ls "$CENTAUR_OVERLAY_DIR"
ls "$CENTAUR_OVERLAY_DIR/.agents/skills"

Local checks

uv run pytest