meta_list_custom_conversions

List the custom conversions of a Meta advertiser.

Ask which custom conversion an ad set can optimize for. A custom conversion is a rule on the events of a Pixel, such as a trial start on your welcome page.

Which custom conversions does Northwind have, and which ones still receive events?

The agent calls meta_list_custom_conversions. A long list comes one part at a time. The agent reads each part. You see each custom conversion with its Pixel, its rule and the time of its last event. An archived custom conversion, and one that Meta made unavailable, cannot serve an ad set. The agent does not propose them. Change what runs on Meta shows where this step comes in the job.

Reference

Available on:

List the custom conversions of a Meta ad account. A custom conversion is a rule on the events of a Pixel, such as a StartTrial event on a URL that contains /welcome. Its id is the customConversionId of meta_create_adset. Returns { id, name, customEventType, pixelId, rule, lastFiredTime, usable } per custom conversion. Pick one that is usable and that fired recently. When no answer holds a custom conversion, up to the answer with no nextCursor, the account has none. The answer holds at most limit rows (default 100, maximum 500). When it carries nextCursor, more rows exist: call this tool again with the same arguments and cursor set to that value. When it carries no nextCursor, you have every row.

Input

Argument	Type	Required	Description
`advertiserId`	string	yes	Advertiser account ID (`acc_<id>`). Must belong to the active organization — find one with `list_advertisers`.
`cursor`	string, at least 1 character	no	The `nextCursor` of the previous page. Omit it to get the first page. Send it with no change, and with the same filters as the request that answered it: a cursor from a different query gets a 400 `invalid_cursor`. Do not build or change a cursor.
`limit`	integer, 1 to 500	no	The greatest number of rows on the page, from 1 to 500. The default is 100. A greater value gets a 400, with `error` of `invalid_request`. Default: `100`.

Output

A successful call returns this object in structuredContent.

Field	Type	Always present	Description
`customConversions`	array of object	yes	The custom conversions of the advertiser, in the order of Meta. The list can be empty when `nextCursor` is present. Then more custom conversions can exist.
`customConversions[].customEventType`	string or null	yes	The standard event that the custom conversion counts as, in the words of Meta: `START_TRIAL`, `LEAD`. Null when Meta sends none.
`customConversions[].id`	string	yes	The Meta id of the custom conversion. It is the `customConversionId` of `meta_create_adset`, to optimize an ad set for this custom conversion.
`customConversions[].lastFiredTime`	string or null	yes	The time of the last event that matched the rule, as Meta writes it (ISO 8601). Null for a custom conversion that never fired.
`customConversions[].name`	string	yes	The name of the custom conversion in Meta.
`customConversions[].pixelId`	string or null	yes	The Meta id of the Pixel whose events the rule reads. Null for a custom conversion of another source.
`customConversions[].rule`	string or null	yes	The rule of the custom conversion: the JSON of Meta, as a string. Null when Meta sends none.
`customConversions[].usable`	boolean	yes	False when Meta archived the custom conversion or made it unavailable. Do not optimize an ad set for a custom conversion that is not usable.
`nextCursor`	string	no	Send this value as `cursor` to get the next page. It is absent on the last page.

Failure codes

A failed call has isError set, and structuredContent.error holds one of these codes. Errors describes the shape of a failed call.

not_found
provider_not_connected
provider_error
invalid_cursor
organization_unentitled
forbidden
invalid_request
internal_error

Scope

The token must hold observe:read. Auth & scopes lists each scope.

Annotations

A client reads these hints. A hint that the tool does not declare has the default value of the MCP specification.

Read-only. The tool changes nothing.
Open world. The tool reaches a system outside AdCrunch, such as an ad platform.

Example

The arguments:

{
  "advertiserId": "acc_1485443900032333",
  "limit": 2
}

The result, in structuredContent:

{
  "customConversions": [
    {
      "customEventType": "START_TRIAL",
      "id": "901234567890123",
      "lastFiredTime": "2026-09-24T07:58:40+0000",
      "name": "Trial started",
      "pixelId": "812345678901234",
      "rule": "{\"and\":[{\"event\":{\"eq\":\"StartTrial\"}},{\"url\":{\"i_contains\":\"/welcome\"}}]}",
      "usable": true
    },
    {
      "customEventType": "LEAD",
      "id": "901234567890124",
      "lastFiredTime": null,
      "name": "Old lead form",
      "pixelId": "812345678901234",
      "rule": "{\"and\":[{\"event\":{\"eq\":\"Lead\"}}]}",
      "usable": false
    }
  ]
}