# correct

URL: /business/nouns/thing/correct · Id: `verb:Thing.correct` · Call: `await $.Thing.correct({ … })` (SDK) or the `do` tool at `https://api.sb/mcp`. Inputs says what to pass, Outputs what returns, When it waits who approves.

> Correct fixes one field of a record that was wrong when served, keeps the value it replaced and tells every Customer who read it.

Correct fixes one field of a record that was wrong when served, keeps the value it replaced and tells every [Customer](/business/nouns/customer) who read it.

## Inputs
| Input | Type | Required | Description |
| --- | --- | --- | --- |
| `thing` | [Thing](/business/nouns/thing) | Yes | The record. |
| `field` | `string` | Yes | The field that was wrong. |
| `value` | `string` | Yes | The right value. |
| `reason` | `text` | Yes | Why it was wrong. |
| `evidence` | `url` | Yes | The Source that shows the right value. |

## Outputs
| Output | Type | Required | Description |
| --- | --- | --- | --- |
| `thing` | [Thing](/business/nouns/thing) | Yes | The corrected record. |

## Effects
| Fact | Value |
| --- | --- |
| Action class | None: no approval rule names it, so it runs within its seat's Permissions and Limits |
| Stakes | The Startup's own records only |
| Door | Two-way: it runs at once |
| Modes | `try` previews it and stores nothing; `send` returns a pending Action; `do` (default) waits for the result |
| Idempotent | Only with a key: a repeat with the same `Idempotency-Key` and input returns the first Action, the same key with other input is refused with `409`, and a repeat without a key runs again |
| Undo | [Action.undo](/business/nouns/action/undo) reverses it |
| Emits | [`Thing.corrected`](/business/events/Thing.corrected) |
| Performed by | The [Data Engineer](/agents/engineering/data-engineer) |

- Each Customer that read the wrong value gets `Thing.corrected` in its change feed and webhooks.

## Refuses when
| Check | Error | Fix | Then call |
| --- | --- | --- | --- |
| The key is valid, but its scopes do not allow this operation | [`forbidden`](/code/api/errors/forbidden) | Use a key whose scopes cover the operation, or ask an owner of the namespace to grant them. | None. |
| `thing` is missing, or is not a thing | [`invalid-input`](/code/api/errors/invalid-input) | Send `thing` as a thing, then call it again. | None. |
| `field` is missing, or is not a string | [`invalid-input`](/code/api/errors/invalid-input) | Send `field` as a string, then call it again. | None. |
| `value` is missing, or is not a string | [`invalid-input`](/code/api/errors/invalid-input) | Send `value` as a string, then call it again. | None. |
| `reason` is missing, or is not a text | [`invalid-input`](/code/api/errors/invalid-input) | Send `reason` as a text, then call it again. | None. |
| `evidence` is missing, or is not a url | [`invalid-input`](/code/api/errors/invalid-input) | Send `evidence` as a url, then call it again. | None. |
| The `Idempotency-Key` was sent before with another operation or other input | [`idempotency-mismatch`](/code/api/errors/idempotency-mismatch) | Send a new key for new input; reuse a key only to retry the same request. | None. |

## When it waits
| Gate | Default |
| --- | --- |
| Decision class | Low: two-way, no delay window |
| [Delay window](/systems/trust-and-governance/controls/one-way-windows) | None: it runs once review passes. |
| Limit | The call [Limit](/business/nouns/limit) of the [Permission](/business/nouns/permission) it runs under. |
| Over the Limit | It waits `pending` for an [Approval](/business/nouns/approval), which a Human answers: the owner of record, or a Human they named to approve for the [Founder](/agents/founding/founder) seat. Approved, it runs; refused, it ends `refused` with [`limit-exceeded`](/code/api/errors/limit-exceeded); unanswered by its deadline, it ends `canceled`. |

## Example

**Ask**

```text
Correct the latest thing.
```

**API**

```bash
curl -X POST https://api.sb/leaseline.app/things/thing_8ds0r9vvRl/correct \
  -H "Authorization: Bearer $SB_TOKEN" \
  -H "Idempotency-Key: leaseline-thing-correct-1" \
  -H "Content-Type: application/json" \
  -d '{"field":"Example field","value":"Example value","reason":"Example reason","evidence":"https://leaseline.app"}'
```

```json
{
  "api": "https://api.sb/leaseline.app",
  "thing": {
    "$id": "https://api.sb/leaseline.app/things/thing_8ds0r9vvRl",
    "$type": "Thing",
    "id": "Example id",
    "type": [
      "noun_v0akLUrXCN"
    ]
  },
  "action": {
    "$id": "https://api.sb/leaseline.app/actions/act_br07HsG8MG",
    "operation": "Thing.correct",
    "status": "done"
  },
  "links": {
    "self": "https://api.sb/leaseline.app/actions/act_br07HsG8MG"
  }
}
```

**CLI**

```bash
npx startup-builder do Thing.correct --data '{"thing":"thing_8ds0r9vvRl","field":"Example field","value":"Example value","reason":"Example reason","evidence":"https://leaseline.app"}' \
  --idempotency-key leaseline-thing-correct-1
```

**MCP**

```json
{
  "name": "do",
  "arguments": {
    "code": "return await $.Thing.correct({ thing: 'thing_8ds0r9vvRl', field: 'Example field', value: 'Example value', reason: 'Example reason', evidence: 'https://leaseline.app' })",
    "idempotencyKey": "leaseline-thing-correct-1"
  }
}
```

**SDK**

```ts
import { $ } from 'startup-builder'

const thing = await $.Thing.correct({ thing: 'thing_8ds0r9vvRl', field: 'Example field', value: 'Example value', reason: 'Example reason', evidence: 'https://leaseline.app' }, { idempotencyKey: 'leaseline-thing-correct-1' })
```

To retry, send the same `Idempotency-Key`: the retry returns the first Action and runs nothing twice. A new key runs the call again.