Antithesis Launch

Skill version: 2026-10-15 84b188a

Prerequisites

• DO NOT PROCEED if snouty is not installed. See https://raw.githubusercontent.com/antithesishq/snouty/refs/heads/main/README.md for installation options.
• DO NOT PROCEED if snouty is older than 0.8.0. Use snouty --version to find the version. Use snouty update to update.
• Run snouty doctor. It checks the container runtime and the compose CLI. Report both to the user and build with that same pair. This skill writes docker compose; use docker-compose instead when that is the CLI snouty names.

Goal

Launch an Antithesis run in this order only:

1. docker compose build (skip if directed to use pre-built images)
2. snouty validate
3. if validation fails, stop and report the error
4. snouty launch

Required Input

• duration in minutes is required. If the user did not provide it, ask before submitting the run.

Discovery

• Start from any user-provided path, command, or Antithesis directory name.
• Otherwise, inspect the repo to understand how the harness is wired. Check nearby AGENTS.md, README*, Makefile*, and Antithesis-specific scripts before choosing commands.
• Find the config directory by locating the docker-compose.yaml intended for Antithesis. Prefer directories like antithesis/config, but support non-standard layouts.
• Treat these as strong Antithesis signals: nearby scratchbook/ or test/ directories, compose content mentioning /opt/antithesis, ANTITHESIS_ env vars, setup_complete, or existing snouty examples.
• If multiple compose files look plausible, prefer the one referenced by repo docs or existing snouty launch examples. If the choice is still ambiguous, ask the user instead of guessing.
• Use the directory containing docker-compose.yaml as the snouty validate <CONFIG> and snouty launch --config <CONFIG> argument.
• Build against that exact file: docker compose -f <CONFIG>/docker-compose.yaml build.
• snouty never builds or pulls images, so every image must already be in the store of the engine snouty selects. snouty prefers podman when both engines are installed.
  • Use SNOUTY_CONTAINER_ENGINE=docker to force snouty to use docker's store.
• When using podman, build with podman compose -f <CONFIG>/docker-compose.yaml build. That wrapper execs Docker Compose v2 against podman's API socket, so the image lands in podman's store. Check the provider first: podman compose version must print Docker Compose version ..., because podman falls back to the podman-compose Python tool when it finds no Compose v2 binary.

Run Arguments

• Determine the launcher in this order: explicit user input, existing repo docs/scripts/examples, otherwise default to basic_test when using a docker-compose.yaml file and to basic_k8s_test when using a kubernetes setup.
• If explicitly directed to launch a run against a pre-built image, run snouty launch --config-image <CONFIG_IMAGE> with the user-supplied image reference.
• Otherwise, use snouty launch --config <CONFIG>, which requires ANTITHESIS_REPOSITORY. Reuse the current environment if it is already set. If not, stop and ask the user for it.
• Always set all of these explicitly:
  • --duration: the user-provided duration
  • --source: repo name
  • --test-name: repo name plus branch or config name
  • --description: short, readable description of the run, including details such as the branch name, current goal, or what you changed since the last run.
• Allow overrides: When the user or another skill invoking this one specifies a launch parameter, use what they gave you instead of the defaults described above.

Execution

• These commands can take a long time. Prefer background execution or generous timeouts instead of assuming quick completion.
• Do not run snouty launch unless the build succeeded and snouty validate exited successfully.

docker compose -f "$CONFIG_DIR/docker-compose.yaml" build
snouty validate "$CONFIG_DIR"
snouty launch \
  --json \
  --launcher "$LAUNCHER" \
  --config "$CONFIG_DIR" \
  --duration "$DURATION" \
  --source "$SOURCE" \
  --test-name "$TEST_NAME" \
  --description "$DESCRIPTION"

Output

• Report the config directory, compose build command, validate command, and final snouty launch command shape before submission.
• If validation fails, stop immediately and show the failing command plus the key error.
• The --json flag makes snouty launch emit machine-readable output containing a run_id. Parse and report the run_id — it's needed to triage the run when it is done.

Self-Review

• The chosen config directory is the one that actually contains the Antithesis docker-compose.yaml.
• The build, validate, and run steps all point at the same config.
• snouty validate succeeded before snouty launch was invoked.
• The run set source, test-name, description, and duration explicitly, using any caller-supplied values in preference to the defaults as well as any caller-supplied additional parameters.
• The build used the compose CLI and container engine snouty doctor reported.
• Missing blockers such as duration, ANTITHESIS_REPOSITORY, or an ambiguous config location caused a stop instead of a bad submission.