Run

The run key defines the commands a task executes. It can be a single command or a multi-line script.

tasks:
  - key: greet
    run: echo hello

  - key: build
    run: |
      echo building
      make build

How your script runs

RWX runs your script with a couple of safety defaults. They're worth knowing about because they change what happens when a command fails.

A failing command stops the task

If any command exits with an error, the script stops right there and the task fails. Commands after the failing one don't run.

tasks:
  - key: example
    run: |
      echo before
      false # this fails…
      echo after # …so this never runs, and the task fails

This surfaces failures instead of letting a broken step slip by. (If you've used shell scripts before, this is set -e, also called errexit.)

If a particular command is allowed to fail, you can add || true so its result is ignored:

run: rm cache.txt || true # don't fail the task if the file isn't there

A failing step in a pipeline fails the task

When you connect commands with |, the task fails if any command in the chain fails. For example, generate-report | tee report.txt fails if generate-report fails, even though tee succeeds. This behavior (known as pipefail) applies when your image includes Bash, which most do.

The shell RWX uses

The shell is chosen automatically based on your base image:

• If the image includes Bash (most do, like ubuntu:24.04), scripts run with /bin/bash -l -e -o pipefail.
• Otherwise (like alpine), scripts run with /bin/sh -l -e. This behaves the same, except it doesn't have the pipeline behavior described above.

Either way it runs as a login shell (the -l), so your PATH and other profile settings are loaded the way you'd expect in a normal terminal.