---
title: Merge a fault into another
description: Merges the fault in the path into the fault named by target_fault_id.
url: https://docs.honeybadger.io/api/v3/faults/merge-faults/
---

API v3 is in preview

Endpoints and response shapes [can change before general availability](https://docs.honeybadger.io/api/v3/#preview). API v2 is unchanged.

POST `https://app.honeybadger.io/v3/projects/{project_id}/faults/{fault_id}/merge`

[Required scope](https://docs.honeybadger.io/api/v3/authentication/#scopes) `faults:write`

Merges the fault in the path into the fault named by `target_fault_id`. Its notices, comments, tickets, notification opt-outs, Actions runs and merge history move to the target, and its tags, assignee and resolved or ignored state are dropped.

The merge runs in the background, so the response is 202. Until it finishes, the merged fault can still be read and written; once it’s done, a GET on it redirects (301) to the target. The redirect lasts about as long as the project’s retention, and then the old ID returns 404.

Example request

```sh
curl -X POST "https://app.honeybadger.io/v3/projects/$PROJECT_ID/faults/$FAULT_ID/merge" \
  -H "Authorization: Bearer $HONEYBADGER_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
  "target_fault_id": "12345"
}'
```

## Parameters

### Path parameters

| Field | Type | Description |
| - | - | - |
| `project_id` required | string | Project ID. |
| `fault_id` required | string | Fault ID. |

## Request body

Names the fault to merge into

| Field | Type | Description |
| - | - | - |
| `target_fault_id` required | string | ID of the fault to keep. The fault in the path is merged into it. |

## Responses

### 202 Merge accepted and queued

Example payload

```json
{
  "data": {
    "batch_id": "WksB67FpRY3bZQ",
    "source_id": "12345",
    "target_id": "67890"
  },
  "meta": {
    "request_id": "6f1c2b0e-8d4a-4f6e-9b2a-3c5d7e9f1a2b"
  }
}
```

Response schema

| Field | Type | Description |
| - | - | - |
| `data` required | object | A queued merge. |
| `data.batch_id` required | string | Identifies the background merge. |
| `data.source_id` required | string | ID of the fault being merged, from the path. |
| `data.target_id` required | string | ID of the fault kept. |
| `meta` | object | |
| `meta.request_id` | string | Unique identifier for the request, for correlating with support. |

## Errors

### 401 Unauthorized

The credential is missing, invalid, expired or revoked (`unauthorized`), or was sent in a way v3 doesn’t accept (see the examples).

Example payload: unauthorized (Missing, malformed, expired or revoked credential)

```json
{
  "error": {
    "code": "unauthorized",
    "message": "Access denied"
  },
  "meta": {
    "request_id": "abc123"
  }
}
```

Example payload: unsupported\_auth\_scheme (Sent as HTTP basic, which v3 does not accept)

```json
{
  "error": {
    "code": "unsupported_auth_scheme",
    "message": "Send the credential as `Authorization: Bearer <token>`; v3 does not accept HTTP basic"
  },
  "meta": {
    "request_id": "abc123"
  }
}
```

Example payload: credential\_in\_query (Sent as the \`auth\_token\` query parameter)

```json
{
  "error": {
    "code": "credential_in_query",
    "message": "Credentials must be sent in the Authorization header"
  },
  "meta": {
    "request_id": "abc123"
  }
}
```

Response schema

| Field | Type | Description |
| - | - | - |
| `error` required | object | |
| `error.code` required | string | Machine-readable code. Branch on this, not the message. Allowed values: `unauthorized`, `unsupported_auth_scheme`, `credential_in_query`, `access_denied`, `insufficient_scope`, `requires_user_token`, `project_restricted`, `account_inactive`, `account_parked`, `feature_unavailable`, `not_found`, `validation_error`, `delete_failed`, `limit_reached`, `rate_limit_exceeded`, `concurrent_request`, `streams_provisioning`, `ingestion_key_not_accepted`, `maintenance_mode`, `invalid_parameter`, `forbidden_attributes`, `service_unavailable`, `ambiguous_account`, `fault_merged`. |
| `error.message` required | string | Human-readable explanation. |
| `error.details` | array\<object> \| object | A list of `{field, message}` on `validation_error` and `invalid_parameter`, and on `feature_unavailable` or `limit_reached` when one field caused the refusal; `{required_scope, token_scopes}` on `insufficient_scope`; `{merged_into, location}` on `fault_merged`. Absent when there's nothing to add. |
| `meta` | object | |
| `meta.request_id` | string | Unique identifier for the request, for correlating with support. |

### 403 Forbidden

The credential isn’t allowed to do this. `error.code` says why. An account or project the credential doesn’t cover is 404 `not_found`, not 403.

Example payload: access\_denied (The credential isn't allowed to do this to this record)

```json
{
  "error": {
    "code": "access_denied",
    "message": "Access denied"
  },
  "meta": {
    "request_id": "abc123"
  }
}
```

Example payload: insufficient\_scope (The credential lacks the permission this endpoint requires)

```json
{
  "error": {
    "code": "insufficient_scope",
    "message": "Insufficient scope",
    "details": {
      "required_scope": "faults:write",
      "token_scopes": [
        "faults:read",
        "insights:read"
      ]
    }
  },
  "meta": {
    "request_id": "abc123"
  }
}
```

Example payload: requires\_user\_token (The endpoint records who acted, and an account token has nobody)

```json
{
  "error": {
    "code": "requires_user_token",
    "message": "This endpoint records the person who acted, so it requires a user credential rather than an account token"
  },
  "meta": {
    "request_id": "abc123"
  }
}
```

Example payload: project\_restricted (A project-restricted credential cannot create a project)

```json
{
  "error": {
    "code": "project_restricted",
    "message": "Project-restricted tokens cannot create projects"
  },
  "meta": {
    "request_id": "abc123"
  }
}
```

Response schema

| Field | Type | Description |
| - | - | - |
| `error` required | object | |
| `error.code` required | string | Machine-readable code. Branch on this, not the message. Allowed values: `unauthorized`, `unsupported_auth_scheme`, `credential_in_query`, `access_denied`, `insufficient_scope`, `requires_user_token`, `project_restricted`, `account_inactive`, `account_parked`, `feature_unavailable`, `not_found`, `validation_error`, `delete_failed`, `limit_reached`, `rate_limit_exceeded`, `concurrent_request`, `streams_provisioning`, `ingestion_key_not_accepted`, `maintenance_mode`, `invalid_parameter`, `forbidden_attributes`, `service_unavailable`, `ambiguous_account`, `fault_merged`. |
| `error.message` required | string | Human-readable explanation. |
| `error.details` | array\<object> \| object | A list of `{field, message}` on `validation_error` and `invalid_parameter`, and on `feature_unavailable` or `limit_reached` when one field caused the refusal; `{required_scope, token_scopes}` on `insufficient_scope`; `{merged_into, location}` on `fault_merged`. Absent when there's nothing to add. |
| `meta` | object | |
| `meta.request_id` | string | Unique identifier for the request, for correlating with support. |

### 404 Not Found

Resource not found

Example payload

```json
{
  "error": {
    "code": "not_found",
    "message": "Resource not found"
  },
  "meta": {
    "request_id": "abc123"
  }
}
```

Response schema

| Field | Type | Description |
| - | - | - |
| `error` required | object | |
| `error.code` required | string | Machine-readable code. Branch on this, not the message. Allowed values: `unauthorized`, `unsupported_auth_scheme`, `credential_in_query`, `access_denied`, `insufficient_scope`, `requires_user_token`, `project_restricted`, `account_inactive`, `account_parked`, `feature_unavailable`, `not_found`, `validation_error`, `delete_failed`, `limit_reached`, `rate_limit_exceeded`, `concurrent_request`, `streams_provisioning`, `ingestion_key_not_accepted`, `maintenance_mode`, `invalid_parameter`, `forbidden_attributes`, `service_unavailable`, `ambiguous_account`, `fault_merged`. |
| `error.message` required | string | Human-readable explanation. |
| `error.details` | array\<object> \| object | A list of `{field, message}` on `validation_error` and `invalid_parameter`, and on `feature_unavailable` or `limit_reached` when one field caused the refusal; `{required_scope, token_scopes}` on `insufficient_scope`; `{merged_into, location}` on `fault_merged`. Absent when there's nothing to add. |
| `meta` | object | |
| `meta.request_id` | string | Unique identifier for the request, for correlating with support. |

### 409 Conflict

This fault was merged into another, so the write wasn’t applied. `error.details` names the fault it was merged into.

Example payload

```json
{
  "error": {
    "code": "fault_merged",
    "message": "This fault was merged into fault 12345",
    "details": {
      "merged_into": "12345",
      "location": "https://app.honeybadger.io/v3/projects/Xk9mZp/faults/12345"
    }
  },
  "meta": {
    "request_id": "abc123"
  }
}
```

Response schema

| Field | Type | Description |
| - | - | - |
| `error` required | object | |
| `error.code` required | string | Machine-readable code. Branch on this, not the message. Allowed values: `unauthorized`, `unsupported_auth_scheme`, `credential_in_query`, `access_denied`, `insufficient_scope`, `requires_user_token`, `project_restricted`, `account_inactive`, `account_parked`, `feature_unavailable`, `not_found`, `validation_error`, `delete_failed`, `limit_reached`, `rate_limit_exceeded`, `concurrent_request`, `streams_provisioning`, `ingestion_key_not_accepted`, `maintenance_mode`, `invalid_parameter`, `forbidden_attributes`, `service_unavailable`, `ambiguous_account`, `fault_merged`. |
| `error.message` required | string | Human-readable explanation. |
| `error.details` | array\<object> \| object | A list of `{field, message}` on `validation_error` and `invalid_parameter`, and on `feature_unavailable` or `limit_reached` when one field caused the refusal; `{required_scope, token_scopes}` on `insufficient_scope`; `{merged_into, location}` on `fault_merged`. Absent when there's nothing to add. |
| `meta` | object | |
| `meta.request_id` | string | Unique identifier for the request, for correlating with support. |

### 422 Unprocessable Content

Validation error

Example payload

```json
{
  "error": {
    "code": "validation_error",
    "message": "Name can't be blank",
    "details": [
      {
        "field": "name",
        "message": "can't be blank"
      }
    ]
  },
  "meta": {
    "request_id": "abc123"
  }
}
```

Response schema

| Field | Type | Description |
| - | - | - |
| `error` required | object | |
| `error.code` required | string | Machine-readable code. Branch on this, not the message. Allowed values: `unauthorized`, `unsupported_auth_scheme`, `credential_in_query`, `access_denied`, `insufficient_scope`, `requires_user_token`, `project_restricted`, `account_inactive`, `account_parked`, `feature_unavailable`, `not_found`, `validation_error`, `delete_failed`, `limit_reached`, `rate_limit_exceeded`, `concurrent_request`, `streams_provisioning`, `ingestion_key_not_accepted`, `maintenance_mode`, `invalid_parameter`, `forbidden_attributes`, `service_unavailable`, `ambiguous_account`, `fault_merged`. |
| `error.message` required | string | Human-readable explanation. |
| `error.details` | array\<object> \| object | A list of `{field, message}` on `validation_error` and `invalid_parameter`, and on `feature_unavailable` or `limit_reached` when one field caused the refusal; `{required_scope, token_scopes}` on `insufficient_scope`; `{merged_into, location}` on `fault_merged`. Absent when there's nothing to add. |
| `meta` | object | |
| `meta.request_id` | string | Unique identifier for the request, for correlating with support. |

---

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