ACP Harness Docker Sandbox

Talon does not depend on third-party ACP Docker images. Build the local sandbox image from this repository, then reference that image from a SandboxClass.

docker build \
  -f dockerfiles/codex-acp.Dockerfile \
  -t talon-acp-harness:local \
  .

Main branch publishes the same image to GHCR:

ghcr.io/impalasys/talon-acp-harness:latest
ghcr.io/impalasys/talon-acp-harness:sha-<git-sha>
ghcr.io/impalasys/talon-codex-acp:latest
ghcr.io/impalasys/talon-codex-acp:sha-<git-sha>
ghcr.io/impalasys/talon-claude-code-acp:latest
ghcr.io/impalasys/talon-claude-code-acp:sha-<git-sha>
ghcr.io/impalasys/talon-opencode-acp:latest
ghcr.io/impalasys/talon-opencode-acp:sha-<git-sha>

The image contains:

OpenAI Codex CLI from @openai/codex
Zed’s Codex ACP adapter from @zed-industries/codex-acp
Anthropic Claude Code CLI from @anthropic-ai/claude-code
Zed’s Claude Code ACP adapter from @zed-industries/claude-code-acp
OpenCode CLI from opencode-ai
Common coding tools: Git, SSH client, Python, ripgrep, jq, curl, and a build toolchain

Do not bake API keys into the image. Pass credentials at runtime through the Talon sandbox backend or local Docker environment.

For the local company-builder example, apply:

talon-cli apply -f manifests/examples/v2-company-builder/sandbox-class-docker.yaml

That manifest uses:

apiVersion: talon.impalasys.com/v1
kind: SandboxClass
metadata:
  name: docker-code
  namespace: system
spec:
  provider: docker
  providerConfig:
    image: talon-acp-harness:local
  credentials: {}

When Talon leases a Docker sandbox from a SandboxPolicy that points at this class, the Docker backend starts the container and the ACP runtime launches the configured ACP harness inside it.

Talon recognizes these harnessRef aliases:

runtime:
  kind: acp
  acp:
    harnessRef: codex
    cwd: /workspace
    sandboxPolicyRef: coding

runtime:
  kind: acp
  acp:
    harnessRef: claude-code
    cwd: /workspace
    sandboxPolicyRef: coding

runtime:
  kind: acp
  acp:
    harnessRef: opencode
    cwd: /workspace
    sandboxPolicyRef: coding

codex resolves to codex-acp, claude-code resolves to claude-code-acp, and opencode resolves to opencode acp. Talon forwards matching process environment keys when present: OPENAI_API_KEY and CODEX_API_KEY for Codex, ANTHROPIC_API_KEY for Claude Code, and OPENCODE_API_KEY plus common provider keys for OpenCode.

The opt-in smoke test uses the same default image:

TALON_CODEX_ACP_TEST=1 cargo test harness::acp::tests::codex_acp_starts_inside_docker_sandbox_when_enabled

Override the image with TALON_CODEX_ACP_IMAGE when testing a registry-published build. Set TALON_CODEX_ACP_PLATFORM only when you intentionally want Docker to pull or run a specific image platform.

The live Python e2e can run any supported harness:

TALON_ACP_DOCKER_E2E=1 \
TALON_ACP_E2E_HARNESS=codex \
TALON_ACP_E2E_IMAGE=ghcr.io/impalasys/talon-acp-harness:latest \
pytest tests/test_chat_sqlite.py -k live_acp

For the pytest path, set TALON_ACP_E2E_HARNESS to codex, claude-code, or opencode, and provide the matching credential in the environment or repo .env: CODEX_API_KEY/OPENAI_API_KEY for Codex, ANTHROPIC_API_KEY for Claude Code, or OPENCODE_API_KEY plus provider keys for OpenCode. The legacy TALON_CODEX_DOCKER_E2E and TALON_CODEX_ACP_IMAGE variables still work for Codex mode.