> This is the Markdown of https://backed.giving/developers/reference/milestones, a page of the Backed developer documentation. Every page is listed at https://backed.giving/developers/llms.txt.
# Milestones
Milestones with their deliverables. 4 operations: parameters, request body and answers, with examples.
- [GET /api/v2/milestones](#listMilestones) — List milestones.
- [POST /api/v2/milestones](#createMilestone) — Create a milestone on a funding application.
- [GET /api/v2/milestones/{id}](#getMilestone) — Get one milestone.
- [POST /api/v2/milestones/{id}/approve](#approveMilestone) — Approve a milestone.
## GET /api/v2/milestones
**List milestones.**
Every milestone of the Organisation (application, contract and standalone) in ascending id order, at most 50 a page, each with its deliverables entry. Every filter is ANDed; any other `filters[…]` key is 400.
- Operation ID: `listMilestones`
- Authentication: A Bearer token from a credential holding the `read` scope.
- Also served at `/funding_system/api/v2/milestones`, the documented product’s alias path.
Example request:
```bash
curl "https://your-org.backed.giving/api/v2/milestones" \
-H "Authorization: Bearer $BACKED_TOKEN"
```
### Parameters
Parameters of GET /api/v2/milestones:
| Name | In | Required | Type | Description |
| --- | --- | --- | --- | --- |
| `limit` | query | No | `integer` | Results per page (default 50, at most 50; a larger value is read as 50). Not an integer, or below 1: 400. Example: `50`. |
| `gt` | query | No | `integer` | Return records with an id greater than this value. Page forward by passing the last id you received. Example: `1287`. |
| `lt` | query | No | `integer` | Return records with an id less than this value. |
| `filters[deliverables][value]` | query | No | `string` | Match deliverable input values; `%` is a wildcard for partial matching. Example: `%Smith%`. |
| `filters[deliverables][tags][]` | query | No | `array of string` | Filter by the internal\_identifier of deliverable fields. Example: `artist_name, song_title`. |
| `filters[deliverables][tag]` | query | No | `string` | Combine a tag with filters\[deliverables\]\[value\] to search within one field. Example: `artist_name`. |
| `filters[ids][]` | query | No | `array of integer` | Filter by milestone ids. Example: `2210, 2211`. |
### 200 response
A JSON array of milestones.
Fields of Milestone:
| Field | Type | Required | Notes |
| --- | --- | --- | --- |
| `id` | `integer` | Yes | |
| `created_at` | `string` | Yes | |
| `updated_at` | `string` | Yes | |
| `title` | `string` | Yes | |
| `contract_id` | `integer \| null` | Yes | |
| `funding_amount` | `string` | Yes | |
| `description` | `string \| null` | Yes | |
| `state` | `string` | Yes | One of `not_submitted`, `pending_review`, `submitted_to_verifier`, `submitted`, `resubmission_requested`, `approved`, `finance_approved`. |
| `paid_at` | `string \| null` | Yes | |
| `decline_reason` | `string \| null` | Yes | |
| `due_date` | `string` | Yes | |
| `contract` | `object \| null` | Yes | |
| `lock_version` | `integer` | Yes | |
| `deliverables_template_entry` | `object` | Yes | |
Example 200 response:
```json
[
{
"id": 2210,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-06-18T03:40:11.000Z",
"title": "Final report",
"contract_id": 640,
"funding_amount": "4500.0",
"description": "A report on the outcomes the project achieved.",
"state": "submitted",
"paid_at": null,
"decline_reason": null,
"due_date": "2027-06-30",
"contract": {
"id": 640,
"title": "Funding agreement: Te Awa river restoration"
},
"lock_version": 2,
"deliverables_template_entry": {
"id": 9310,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-06-18T03:40:11.000Z",
"inputs": [
{
"id": 77001,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-06-18T03:40:11.000Z",
"value": "final-report.pdf",
"file": {
"filename": "final-report.pdf",
"content_type": "application/pdf",
"byte_size": 482113
},
"tahua_file_url": "https://your-org.backed.giving/api/v2/file_inputs/77001",
"field": {
"id": 950,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-03-02T21:15:04.000Z",
"internal_identifier": "report"
}
}
]
}
}
]
```
### 400 response
A query parameter is invalid, or a write’s body is not a JSON object.
Example 400 response:
```json
{
"error": "invalid_request",
"error_description": "limit is invalid"
}
```
### 401 response
The token is missing, invalid, expired or revoked, of another Organisation, or API access is not Full. Ask for a new token.
Headers: `WWW-Authenticate`.
Example 401 response:
```json
{
"error": "invalid_token",
"error_description": "The access token is invalid or has expired"
}
```
### 403 response
The request was sent over plain HTTP and was not processed.
Example 403 response:
```json
{
"error": "https_required"
}
```
### 404 response
An unknown host or path, or an id that is unknown, deleted or of another Organisation.
Example 404 response:
```json
{
"error": "not_found"
}
```
### 429 response
A rate limit was exceeded: 120 requests a minute per credential, 30 token requests a minute per client\_id.
Headers: `Retry-After`.
Example 429 response:
```json
{
"error": "rate_limited",
"error_description": "Too many requests"
}
```
### 500 response
An unexpected server error.
Example 500 response:
```json
{
"error": "server_error"
}
```
### 503 response
The Organisation’s API access cannot be determined, or a dependency is unavailable. Retry after the given seconds.
Headers: `Retry-After`.
Example 503 response:
```json
{
"error": "temporarily_unavailable"
}
```
## POST /api/v2/milestones
**Create a milestone on a funding application.**
`Create Singular` as the run-as Administrator (`milestones.create`). Needs the Contracts module.
- Operation ID: `createMilestone`
- Authentication: A Bearer token from a credential holding the `write:post_award` scope. Runs as the credential’s Administrator, and needs an `Idempotency-Key` header.
Example request:
```bash
curl -X POST "https://your-org.backed.giving/api/v2/milestones" \
-H "Authorization: Bearer $BACKED_TOKEN" \
-H "Idempotency-Key: 7d1f0c2e-5b8a-4f3e-9c61-2a4b8e9d0f13" \
-H "Content-Type: application/json" \
-d '{"funding_application_id":"1287","title":"Progress report","due_date":"2026-12-15","amount":"5000.00","form_template_id":"61","description":"A six-month progress report."}'
```
### Parameters
Parameters of POST /api/v2/milestones:
| Name | In | Required | Type | Description |
| --- | --- | --- | --- | --- |
| `Idempotency-Key` | header | Yes | `string` | A key of 1 to 255 characters, unique per write. A retry with the same key, method, path and body within 24 hours answers the first response again (with `Idempotent-Replayed: true`) and writes nothing. Example: `7d1f0c2e-5b8a-4f3e-9c61-2a4b8e9d0f13`. |
### Request body
`application/json`, the `MilestoneCreate` schema. A milestone on one funding application, with its deliverables form. Ids are decimal strings and `amount` has two decimal places, as the product’s form takes them.
Fields of the MilestoneCreate body:
| Field | Type | Required | Notes |
| --- | --- | --- | --- |
| `funding_application_id` | `string` | Yes | |
| `title` | `string` | Yes | |
| `due_date` | `string` | Yes | |
| `amount` | `string` | Yes | |
| `form_template_id` | `string` | Yes | |
| `milestone_template_id` | `string \| null` | No | |
| `description` | `string \| null` | No | |
| `reviewer_user_ids` | `array of string` | No | |
Example request body:
```json
{
"funding_application_id": "1287",
"title": "Progress report",
"due_date": "2026-12-15",
"amount": "5000.00",
"form_template_id": "61",
"description": "A six-month progress report."
}
```
### 201 response
The milestone as the single read answers it.
Headers: `Idempotent-Replayed`.
Fields of Milestone:
| Field | Type | Required | Notes |
| --- | --- | --- | --- |
| `id` | `integer` | Yes | |
| `created_at` | `string` | Yes | |
| `updated_at` | `string` | Yes | |
| `title` | `string` | Yes | |
| `contract_id` | `integer \| null` | Yes | |
| `funding_amount` | `string` | Yes | |
| `description` | `string \| null` | Yes | |
| `state` | `string` | Yes | One of `not_submitted`, `pending_review`, `submitted_to_verifier`, `submitted`, `resubmission_requested`, `approved`, `finance_approved`. |
| `paid_at` | `string \| null` | Yes | |
| `decline_reason` | `string \| null` | Yes | |
| `due_date` | `string` | Yes | |
| `contract` | `object \| null` | Yes | |
| `lock_version` | `integer` | Yes | |
| `deliverables_template_entry` | `object` | Yes | |
Example 201 response:
```json
{
"id": 2210,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-06-18T03:40:11.000Z",
"title": "Final report",
"contract_id": 640,
"funding_amount": "4500.0",
"description": "A report on the outcomes the project achieved.",
"state": "submitted",
"paid_at": null,
"decline_reason": null,
"due_date": "2027-06-30",
"contract": {
"id": 640,
"title": "Funding agreement: Te Awa river restoration"
},
"lock_version": 2,
"deliverables_template_entry": {
"id": 9310,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-06-18T03:40:11.000Z",
"inputs": [
{
"id": 77001,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-06-18T03:40:11.000Z",
"value": "final-report.pdf",
"file": {
"filename": "final-report.pdf",
"content_type": "application/pdf",
"byte_size": 482113
},
"tahua_file_url": "https://your-org.backed.giving/api/v2/file_inputs/77001",
"field": {
"id": 950,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-03-02T21:15:04.000Z",
"internal_identifier": "report"
}
}
]
}
}
```
### 400 response
`idempotency_key_required`: The write has no Idempotency-Key header of 1 to 255 characters. `invalid_request`: A query parameter is invalid, or a write’s body is not a JSON object.
Example 400 response: idempotency_key_required:
```json
{
"error": "idempotency_key_required",
"error_description": "A write needs an Idempotency-Key header of 1 to 255 characters"
}
```
Example 400 response: invalid_request:
```json
{
"error": "invalid_request",
"error_description": "limit is invalid"
}
```
### 401 response
The token is missing, invalid, expired or revoked, of another Organisation, or API access is not Full. Ask for a new token.
Headers: `WWW-Authenticate`.
Example 401 response:
```json
{
"error": "invalid_token",
"error_description": "The access token is invalid or has expired"
}
```
### 403 response
`https_required`: The request was sent over plain HTTP and was not processed. `insufficient_scope`: The credential does not hold the scope the route needs. `run_as_disabled`: The credential has no run-as Administrator, or that person is no longer one. `forbidden`: The run-as Administrator lacks the permission, or the record is outside their Data Access Rules.
Headers: `WWW-Authenticate`.
Example 403 response: https_required:
```json
{
"error": "https_required"
}
```
Example 403 response: insufficient_scope:
```json
{
"error": "insufficient_scope",
"error_description": "This credential lacks the write:applications scope"
}
```
Example 403 response: run_as_disabled:
```json
{
"error": "run_as_disabled",
"error_description": "This credential has no enabled run-as Administrator"
}
```
Example 403 response: forbidden:
```json
{
"error": "forbidden",
"error_description": "The run-as Administrator may not do this to this record"
}
```
### 404 response
`not_found`: An unknown host or path, or an id that is unknown, deleted or of another Organisation. `module_disabled`: The Organisation has the module this route belongs to turned off.
Example 404 response: not_found:
```json
{
"error": "not_found"
}
```
Example 404 response: module_disabled:
```json
{
"error": "module_disabled",
"error_description": "This module is not enabled for the Organisation"
}
```
### 409 response
The first request with this Idempotency-Key has not finished. Nothing was written; retry after the given seconds.
Headers: `Retry-After`.
Example 409 response:
```json
{
"error": "idempotency_in_progress",
"error_description": "The first request with this Idempotency-Key has not finished. If this persists it stopped part-way: check whether the record exists before writing again with a new key"
}
```
### 413 response
The body, or the declared file, is larger than the limit that applies.
Example 413 response:
```json
{
"error": "payload_too_large",
"error_description": "The request body is too large"
}
```
### 415 response
The body is not application/json, or the target does not accept the file’s content type.
Example 415 response:
```json
{
"error": "unsupported_media_type",
"error_description": "The request body must be application/json"
}
```
### 422 response
`idempotency_key_reused`: The Idempotency-Key was used in the last 24 hours for a different method, path or body. `unknown_field`: The body has a property the route does not document; the first is named. `validation_failed`: Body values the product’s own form would refuse; `fields` names each.
Example 422 response: idempotency_key_reused:
```json
{
"error": "idempotency_key_reused",
"error_description": "This Idempotency-Key was used for a different request"
}
```
Example 422 response: unknown_field:
```json
{
"error": "unknown_field",
"error_description": "bank_account_number is not a writable field"
}
```
Example 422 response: validation_failed:
```json
{
"error": "validation_failed",
"error_description": "Invalid fields: due_date",
"fields": [
"due_date"
]
}
```
### 429 response
A rate limit was exceeded: 120 requests a minute per credential, 30 token requests a minute per client\_id.
Headers: `Retry-After`.
Example 429 response:
```json
{
"error": "rate_limited",
"error_description": "Too many requests"
}
```
### 500 response
An unexpected server error.
Example 500 response:
```json
{
"error": "server_error"
}
```
### 503 response
The Organisation’s API access cannot be determined, or a dependency is unavailable. Retry after the given seconds.
Headers: `Retry-After`.
Example 503 response:
```json
{
"error": "temporarily_unavailable"
}
```
## GET /api/v2/milestones/{id}
**Get one milestone.**
Exactly the list item, its deliverables entry included. Filters are ignored.
- Operation ID: `getMilestone`
- Authentication: A Bearer token from a credential holding the `read` scope.
- Also served at `/funding_system/api/v2/milestones/{id}`, the documented product’s alias path.
Example request:
```bash
curl "https://your-org.backed.giving/api/v2/milestones/42" \
-H "Authorization: Bearer $BACKED_TOKEN"
```
### Parameters
Parameters of GET /api/v2/milestones/{id}:
| Name | In | Required | Type | Description |
| --- | --- | --- | --- | --- |
| `id` | path | Yes | `integer` | The record id. Anything but a positive integer is 404. Example: `42`. |
### 200 response
The milestone.
Fields of Milestone:
| Field | Type | Required | Notes |
| --- | --- | --- | --- |
| `id` | `integer` | Yes | |
| `created_at` | `string` | Yes | |
| `updated_at` | `string` | Yes | |
| `title` | `string` | Yes | |
| `contract_id` | `integer \| null` | Yes | |
| `funding_amount` | `string` | Yes | |
| `description` | `string \| null` | Yes | |
| `state` | `string` | Yes | One of `not_submitted`, `pending_review`, `submitted_to_verifier`, `submitted`, `resubmission_requested`, `approved`, `finance_approved`. |
| `paid_at` | `string \| null` | Yes | |
| `decline_reason` | `string \| null` | Yes | |
| `due_date` | `string` | Yes | |
| `contract` | `object \| null` | Yes | |
| `lock_version` | `integer` | Yes | |
| `deliverables_template_entry` | `object` | Yes | |
Example 200 response:
```json
{
"id": 2210,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-06-18T03:40:11.000Z",
"title": "Final report",
"contract_id": 640,
"funding_amount": "4500.0",
"description": "A report on the outcomes the project achieved.",
"state": "submitted",
"paid_at": null,
"decline_reason": null,
"due_date": "2027-06-30",
"contract": {
"id": 640,
"title": "Funding agreement: Te Awa river restoration"
},
"lock_version": 2,
"deliverables_template_entry": {
"id": 9310,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-06-18T03:40:11.000Z",
"inputs": [
{
"id": 77001,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-06-18T03:40:11.000Z",
"value": "final-report.pdf",
"file": {
"filename": "final-report.pdf",
"content_type": "application/pdf",
"byte_size": 482113
},
"tahua_file_url": "https://your-org.backed.giving/api/v2/file_inputs/77001",
"field": {
"id": 950,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-03-02T21:15:04.000Z",
"internal_identifier": "report"
}
}
]
}
}
```
### 401 response
The token is missing, invalid, expired or revoked, of another Organisation, or API access is not Full. Ask for a new token.
Headers: `WWW-Authenticate`.
Example 401 response:
```json
{
"error": "invalid_token",
"error_description": "The access token is invalid or has expired"
}
```
### 403 response
The request was sent over plain HTTP and was not processed.
Example 403 response:
```json
{
"error": "https_required"
}
```
### 404 response
An unknown host or path, or an id that is unknown, deleted or of another Organisation.
Example 404 response:
```json
{
"error": "not_found"
}
```
### 429 response
A rate limit was exceeded: 120 requests a minute per credential, 30 token requests a minute per client\_id.
Headers: `Retry-After`.
Example 429 response:
```json
{
"error": "rate_limited",
"error_description": "Too many requests"
}
```
### 500 response
An unexpected server error.
Example 500 response:
```json
{
"error": "server_error"
}
```
### 503 response
The Organisation’s API access cannot be determined, or a dependency is unavailable. Retry after the given seconds.
Headers: `Retry-After`.
Example 503 response:
```json
{
"error": "temporarily_unavailable"
}
```
## POST /api/v2/milestones/{id}/approve
**Approve a milestone.**
`Approve Milestone` at its current version (`milestones.approve`), within the run-as Administrator’s Milestone Approval Limit. No body. Needs the Contracts module.
- Operation ID: `approveMilestone`
- Authentication: A Bearer token from a credential holding the `write:post_award` scope. Runs as the credential’s Administrator, and needs an `Idempotency-Key` header.
Example request:
```bash
curl -X POST "https://your-org.backed.giving/api/v2/milestones/42/approve" \
-H "Authorization: Bearer $BACKED_TOKEN" \
-H "Idempotency-Key: 7d1f0c2e-5b8a-4f3e-9c61-2a4b8e9d0f13"
```
### Parameters
Parameters of POST /api/v2/milestones/{id}/approve:
| Name | In | Required | Type | Description |
| --- | --- | --- | --- | --- |
| `id` | path | Yes | `integer` | The record id. Anything but a positive integer is 404. Example: `42`. |
| `Idempotency-Key` | header | Yes | `string` | A key of 1 to 255 characters, unique per write. A retry with the same key, method, path and body within 24 hours answers the first response again (with `Idempotent-Replayed: true`) and writes nothing. Example: `7d1f0c2e-5b8a-4f3e-9c61-2a4b8e9d0f13`. |
### 200 response
The milestone as the single read answers it.
Headers: `Idempotent-Replayed`.
Fields of Milestone:
| Field | Type | Required | Notes |
| --- | --- | --- | --- |
| `id` | `integer` | Yes | |
| `created_at` | `string` | Yes | |
| `updated_at` | `string` | Yes | |
| `title` | `string` | Yes | |
| `contract_id` | `integer \| null` | Yes | |
| `funding_amount` | `string` | Yes | |
| `description` | `string \| null` | Yes | |
| `state` | `string` | Yes | One of `not_submitted`, `pending_review`, `submitted_to_verifier`, `submitted`, `resubmission_requested`, `approved`, `finance_approved`. |
| `paid_at` | `string \| null` | Yes | |
| `decline_reason` | `string \| null` | Yes | |
| `due_date` | `string` | Yes | |
| `contract` | `object \| null` | Yes | |
| `lock_version` | `integer` | Yes | |
| `deliverables_template_entry` | `object` | Yes | |
Example 200 response:
```json
{
"id": 2210,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-06-18T03:40:11.000Z",
"title": "Final report",
"contract_id": 640,
"funding_amount": "4500.0",
"description": "A report on the outcomes the project achieved.",
"state": "submitted",
"paid_at": null,
"decline_reason": null,
"due_date": "2027-06-30",
"contract": {
"id": 640,
"title": "Funding agreement: Te Awa river restoration"
},
"lock_version": 2,
"deliverables_template_entry": {
"id": 9310,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-06-18T03:40:11.000Z",
"inputs": [
{
"id": 77001,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-06-18T03:40:11.000Z",
"value": "final-report.pdf",
"file": {
"filename": "final-report.pdf",
"content_type": "application/pdf",
"byte_size": 482113
},
"tahua_file_url": "https://your-org.backed.giving/api/v2/file_inputs/77001",
"field": {
"id": 950,
"created_at": "2026-03-02T21:15:04.000Z",
"updated_at": "2026-03-02T21:15:04.000Z",
"internal_identifier": "report"
}
}
]
}
}
```
### 400 response
`idempotency_key_required`: The write has no Idempotency-Key header of 1 to 255 characters. `invalid_request`: A query parameter is invalid, or a write’s body is not a JSON object.
Example 400 response: idempotency_key_required:
```json
{
"error": "idempotency_key_required",
"error_description": "A write needs an Idempotency-Key header of 1 to 255 characters"
}
```
Example 400 response: invalid_request:
```json
{
"error": "invalid_request",
"error_description": "limit is invalid"
}
```
### 401 response
The token is missing, invalid, expired or revoked, of another Organisation, or API access is not Full. Ask for a new token.
Headers: `WWW-Authenticate`.
Example 401 response:
```json
{
"error": "invalid_token",
"error_description": "The access token is invalid or has expired"
}
```
### 403 response
`https_required`: The request was sent over plain HTTP and was not processed. `insufficient_scope`: The credential does not hold the scope the route needs. `run_as_disabled`: The credential has no run-as Administrator, or that person is no longer one. `forbidden`: The run-as Administrator lacks the permission, or the record is outside their Data Access Rules. `approval_limit_exceeded`: The amount is above the run-as Administrator’s approval limit.
Headers: `WWW-Authenticate`.
Example 403 response: https_required:
```json
{
"error": "https_required"
}
```
Example 403 response: insufficient_scope:
```json
{
"error": "insufficient_scope",
"error_description": "This credential lacks the write:applications scope"
}
```
Example 403 response: run_as_disabled:
```json
{
"error": "run_as_disabled",
"error_description": "This credential has no enabled run-as Administrator"
}
```
Example 403 response: forbidden:
```json
{
"error": "forbidden",
"error_description": "The run-as Administrator may not do this to this record"
}
```
Example 403 response: approval_limit_exceeded:
```json
{
"error": "approval_limit_exceeded",
"error_description": "The amount is above the run-as Administrator’s approval limit"
}
```
### 404 response
`not_found`: An unknown host or path, or an id that is unknown, deleted or of another Organisation. `module_disabled`: The Organisation has the module this route belongs to turned off.
Example 404 response: not_found:
```json
{
"error": "not_found"
}
```
Example 404 response: module_disabled:
```json
{
"error": "module_disabled",
"error_description": "This module is not enabled for the Organisation"
}
```
### 409 response
`idempotency_in_progress`: The first request with this Idempotency-Key has not finished. Nothing was written; retry after the given seconds. `invalid_transition`: The move is not open from where the record stands; `current_status` says where that is. `invalid_state`: The record is not in a state that admits this write.
Headers: `Retry-After`.
Example 409 response: idempotency_in_progress:
```json
{
"error": "idempotency_in_progress",
"error_description": "The first request with this Idempotency-Key has not finished. If this persists it stopped part-way: check whether the record exists before writing again with a new key"
}
```
Example 409 response: invalid_transition:
```json
{
"error": "invalid_transition",
"error_description": "The record cannot make this move from approved",
"current_status": "approved"
}
```
Example 409 response: invalid_state:
```json
{
"error": "invalid_state",
"error_description": "The target does not take files in its current state"
}
```
### 413 response
The body, or the declared file, is larger than the limit that applies.
Example 413 response:
```json
{
"error": "payload_too_large",
"error_description": "The request body is too large"
}
```
### 415 response
The body is not application/json, or the target does not accept the file’s content type.
Example 415 response:
```json
{
"error": "unsupported_media_type",
"error_description": "The request body must be application/json"
}
```
### 422 response
`idempotency_key_reused`: The Idempotency-Key was used in the last 24 hours for a different method, path or body. `unknown_field`: The body has a property the route does not document; the first is named.
Example 422 response: idempotency_key_reused:
```json
{
"error": "idempotency_key_reused",
"error_description": "This Idempotency-Key was used for a different request"
}
```
Example 422 response: unknown_field:
```json
{
"error": "unknown_field",
"error_description": "bank_account_number is not a writable field"
}
```
### 429 response
A rate limit was exceeded: 120 requests a minute per credential, 30 token requests a minute per client\_id.
Headers: `Retry-After`.
Example 429 response:
```json
{
"error": "rate_limited",
"error_description": "Too many requests"
}
```
### 500 response
An unexpected server error.
Example 500 response:
```json
{
"error": "server_error"
}
```
### 503 response
The Organisation’s API access cannot be determined, or a dependency is unavailable. Retry after the given seconds.
Headers: `Retry-After`.
Example 503 response:
```json
{
"error": "temporarily_unavailable"
}
```