Can I `include` one pipeline yaml in another?

See this example. I tend to prefer cat over echo as it reads cleaner.

In your pipeline.yml file you need a Pipeline upload step:

steps:
  - label: "Yada"
    command: ".buildkite/pipeline.sh | buildkite-agent pipeline upload"

Then in your pipeline.sh file have something like this:

#!/bin/bash
set -eu

cat << EOF
steps:
  - label: "Tada"
    command: "npm start"
EOF