> ## Documentation Index > Fetch the complete documentation index at: https://vexioncards.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Delete a custom field > Deletes a field definition - only when nothing references it (`usage_count` must be 0, otherwise `409 custom_field_in_use`; detach it from every card's `form_builder` first). Scope: `custom_fields:write`. What happens to data: - Stored customer values under this key are PRESERVED on the customer records (history) but stop validating and stop rendering - The `key` becomes available again; re-creating it with a DIFFERENT type is allowed - old stored values simply fail validation on their next write (no silent coercion) ## OpenAPI ````yaml /openapi.json delete /v1/custom_fields/{id} openapi: 3.1.0 info: title: VEXiON cards Public API description: >- ## Rate limiting Two independent layers, checked in this order: 1. **Per-IP throttle (pre-authentication).** Applied to every `/v1` request BEFORE the API key is checked, keyed on the caller's IP address: - **600 requests/minute** per IP - a flood ceiling, `429 rate_limit_error` / `rate_limited`. - **20 failed authentications per 15 minutes** per IP - a key-guessing ceiling. Only responses that are `401` (missing/invalid/revoked key) count against this ceiling; a `403` from a valid key that simply lacks a scope does not. `429 rate_limit_error` / `too_many_failed_attempts`. Both ceilings send `Retry-After` (seconds). 2. **Per-key, per-bucket limiter (post-authentication).** Documented per endpoint (see each operation's `429` response and the `rate_limit` field on the API Key resource) - e.g. 60/min default, 120/min for transactions, plus the notification-broadcast and lookup-filter buckets described on their own endpoints. ### Rate-limit response headers Every rate-limited response carries the legacy `X-RateLimit-Limit` / `X-RateLimit-Remaining` / `X-RateLimit-Reset` family (the last is an **epoch timestamp**) AND the IETF standards-track headers, side by side: - `RateLimit-Policy: "";q=;w=` - the static policy for the bucket that was hit. - `RateLimit: "";r=;t=` - live state. **`t` is a DURATION (seconds remaining), not the epoch timestamp `X-RateLimit-Reset` carries - the two are never the same value.** version: 1.0.0 servers: - url: https://api.vexioncards.one description: Production - url: https://migration.api.vexioncards.one description: Sandbox security: - apiKey: [] tags: - name: Customers - name: Cards - name: Transactions - name: Notifications - name: Locations - name: Products - name: API keys - name: Organization - name: Webhook endpoints - name: Events - name: Custom fields - name: Team members - name: Icons paths: /v1/custom_fields/{id}: delete: tags: - Custom fields summary: Delete a custom field description: >- Deletes a field definition - only when nothing references it (`usage_count` must be 0, otherwise `409 custom_field_in_use`; detach it from every card's `form_builder` first). Scope: `custom_fields:write`. What happens to data: - Stored customer values under this key are PRESERVED on the customer records (history) but stop validating and stop rendering - The `key` becomes available again; re-creating it with a DIFFERENT type is allowed - old stored values simply fail validation on their next write (no silent coercion) operationId: deleteCustomField parameters: - name: id in: path description: Custom field identifier (`cf_` prefix). required: true example: cf_jlgwnmefr6tum774axsvz677py schema: type: string pattern: ^cf_[A-Za-z0-9]+$ - name: Idempotency-Key in: header description: Recommended on PATCH and DELETE for safe retries. required: false example: 8d37b133-db25-412b-9ae3-4c84e142591c schema: type: string responses: '200': description: >- Deletion confirmed. Stored customer values under this key are preserved (see the endpoint description). content: application/json: schema: type: object required: - id - object - deleted properties: id: type: string description: The id of the deleted resource. example: cf_wrxiel4memql2norlmv6teauji object: type: string const: custom_field description: Always `"custom_field"`. deleted: type: boolean const: true description: Always true - the deletion confirmation marker. examples: Deleted: summary: Deletion confirmation value: id: cf_wrxiel4memql2norlmv6teauji object: custom_field deleted: true '401': description: Unauthorized content: application/json: schema: $ref: '#/components/schemas/Error' headers: {} '403': description: Forbidden content: application/json: schema: $ref: '#/components/schemas/Error' headers: {} '404': description: Not found content: application/json: schema: $ref: '#/components/schemas/Error' headers: {} '409': description: Conflict (custom field still referenced by a card) content: application/json: schema: $ref: '#/components/schemas/Error' headers: {} '429': description: Rate limited - respect Retry-After. content: application/json: schema: $ref: '#/components/schemas/Error' '500': description: Server error. Retry-safe on idempotent calls. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: type: api_error code: internal_error message: >- An internal error occurred. The request may be retried with the same Idempotency-Key. doc_url: >- https://vexioncards.mintlify.site/api-reference/errors#internal_error request_id: req_5f8b2c4a9e1d3 examples: Http 500 default: summary: Http 500 default value: error: type: api_error code: internal_error message: >- An internal error occurred. The request may be retried with the same Idempotency-Key. doc_url: >- https://vexioncards.mintlify.site/api-reference/errors#internal_error request_id: req_5f8b2c4a9e1d3 headers: {} deprecated: false components: schemas: Error: type: object required: - error properties: error: type: object required: - type - code - message properties: type: type: string enum: - invalid_request_error - authentication_error - permission_error - not_found_error - rate_limit_error - idempotency_error - api_error code: type: string message: type: string retry_after: type: integer description: >- Seconds to wait before retrying. Present on rate-limit (429) and idempotency-key-in-use (409) errors; mirrors the `Retry-After` HTTP header. Absent on error types that carry no retry guidance. example: 5 param: type: - string - 'null' request_id: type: string doc_url: type: string format: uri field_errors: type: array description: >- Per-field errors on a 422. At most 100 entries: a request with more errors gets the first 100. items: type: object properties: param: type: string code: type: string message: type: string expected_currency: type: string description: >- On `currency_mismatch`: the business currency the request must use. Absent on every other field error. description: >- The error payload: type (category), code (machine-readable), message (human-readable), retry_after (seconds, on rate-limit/idempotency-in-use errors only), param (offending field), request_id, doc_url, field_errors[]. description: >- Standard error envelope. Branch on `error.code`; include `error.request_id` in support requests. See the Errors guide. securitySchemes: apiKey: type: http scheme: bearer description: >- Your secret API key as a Bearer token: `Authorization: Bearer vxn_sk_...`. Keys are created and scoped in the dashboard - see [Authentication](/api-reference/introduction#authentication). ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.