# tally.add

Adds completed tasks to the Tally mini-app's persistent counter.

- Input: `{ "delta": 1 }`, an integer from 1 to 100; defaults to 1.
- Output: `{ "count": 12 }`, the value after the atomic addition.
- Capabilities: `storage.write` to increment and `watcher.display` to redraw.
- Invocation: open Tally in Local's Mini apps host and invoke its registered
  skill there, or call `await sdk.invokeSkill("tally.add", { delta: 1 })` in the app.
  Browser and Watcher Add one controls use this handler.
- Lifecycle: the browser app must be open. Stored values survive restarts;
  disconnecting the device does not undo an increment.
- Errors: invalid deltas fail before writing. A display failure after writing
  can mean the count was saved, so read it before retrying the mutation.

This is an explicit callable app skill, with no automatic voice-tool selection
and no access to another app's state or wallet approval.