Watching

Tasks with source folders and files can be watched and restarted when they change. This is useful, for example, to run API servers that restart when the server code changes.

tasks:
  api:
    src:
      - src
    cmds:
      - node -r ts-node/register src/index.ts

hammerkit api --watch

In watch mode hammerkit watches the src of every task in the run. When a file changes it re-runs the affected task — and, because it knows the dependency graph, any tasks downstream of it — reusing cached results for everything unchanged. A short debounce coalesces bursts of saves into a single restart. Combine --watch with services (via needs, or hammerkit up --watch) to keep a database running while your api restarts on every edit; the development workflow guide puts these together.

Continuous tasksCopy Anchor Link

Some tasks are continuous and watch their files themselves. For example, the Angular CLI watches for file changes and rebuilds incrementally, which is faster than hammerkit restarting the task. Mark such tasks with continuous: true; in watch mode, hammerkit then does not watch their source files.

tasks:
  serve:
    image: node:24
    continuous: true
    src: 
      - src
      - angular.json
    cmds:
      - ng serve