# Add prerequisites while capturing

This guide captures a new task that depends on an existing open task. `&` writes the edge on the new task's Depends-On line. `*` is the reverse: the named existing task depends on the captured one.

## Before you start

Install the CLI and point it at your vault. Have an existing open task with a stable block id, for example `Prep the bench @workshop^prep`. Mac Capture submits the same draft through `bob capture`.

## 1\. Preview a dependent capture

```
bob capture --dry-run 'Sand the bench @workshop^sand &workshop:prep'
```

Output

```
[dry-run] ok would capture  workshop.md
  - [?] #task Sand the bench [created::2026-10-20] [id:: workshop__sand] [dependsOn:: workshop__prep] ^sand
  ⛓ would depend on "Prep the bench"  workshop.md ^prep  [ ] Ready
```

Confirm the preview names `workshop.md`, the new `^sand` id, and the prerequisite `^prep`. An unfinished `&prep` picker is refused; type a complete `&note:block-id`. Quote the draft so the shell leaves `&` alone.

## 2\. Submit and confirm the Depends-On line

```
bob capture 'Sand the bench @workshop^sand &workshop:prep'
```

Output

```
✓ captured  workshop.md
  - [?] #task Sand the bench [created::2026-10-20] [id:: workshop__sand] [dependsOn:: workshop__prep] ^sand
  ⛓ depends on "Prep the bench"  workshop.md ^prep  [ ] Ready
```

Open `workshop.md` and confirm the new task is `[?]` with a first child:

```
- [?] #task Sand the bench [created::2026-10-20] [id:: workshop__sand] [dependsOn:: workshop__prep] ^sand
    - ⛓️ **DEPENDS ON:** [[#^prep]]
```

The Depends-On child is the source of truth; the `[dependsOn::]` field is derived. The prerequisite also gets a generated BLOCKS mirror.

On a Mac, type the same draft in the capture panel, confirm the live preview, and submit. The panel hides only after `bob` reports success.

## 3\. Choose `&` or `*` by direction

`&workshop:prep` means the captured task waits on `^prep`. `*workshop:sand` means `^sand` waits on the captured task (quote `*` on the shell). Exact token rules live in [Capture syntax](<https://bobs-org.github.io/reference/capture-syntax/#ampersand-prereq>).

To add a prerequisite to an existing owner with no new task:

```
bob capture '^workshop:sand &workshop:prep'
```

## If it goes wrong

An unknown note or block id fails the item and rolls the whole draft back. Fix the `&note:block-id` spelling (`&projects/foo:bar` for a nested note). A mid-word `&` is ordinary text. If Mac Capture stays open, the preview still has an error; complete the `&` target and submit again.

## Related

- [Capture](<https://bobs-org.github.io/capture/index.md>)
- [Task dependency links](<https://bobs-org.github.io/task-dependencies/index.md>)
- [Capture syntax](<https://bobs-org.github.io/reference/capture-syntax/index.md>)
- [Capture a task from anywhere on your Mac](<https://bobs-org.github.io/guides/capture-from-your-mac/index.md>)