> ## Documentation Index > Fetch the complete documentation index at: https://docs.nohead.io/llms.txt > Use this file to discover all available pages before exploring further. # Cancel a field migration > A pending migration is cancelled at once. A running one stops at its next batch and is rolled back entirely (`cancel_requested_at` is set until then). Finished migrations cannot be cancelled (`409` with detail code `finished`). ## OpenAPI ````yaml /openapi.json post /v1/migrations/{migration_id}/cancel openapi: 3.1.1 info: title: Nohead API version: 1.0.0 summary: Programmable content and data API. contact: name: Nohead email: hello@nohead.io url: https://nohead.io description: > The Nohead API manages projects, collections (your data models), their fields, and records (your content), with full version history. ## Authentication Send `Authorization: Bearer `. Servers, CI and agents use a project API key (`nohead_sk_...`, or `nohead_pk_...` for a published-only key; created in the web app under API keys) with scopes such as `records:read` or `schema:write`. Organization, project, member and API key management need a person signed in to the web app and are not available to API keys. ## Resources and IDs Every object has an `object` type, and every resource with an identity of its own an opaque, prefixed `id` (`col_`, `fld_`, `rec_`, ...). Record values live under `data`, keyed by each field's `key`. Timestamps are ISO 8601 in UTC. Deleting a record, collection, field, asset or webhook is soft: it can be restored until its `purge_after`. ## Lists Lists return `{ "data": [...], "meta": { "next_cursor", "has_more" } }`. Pass `limit` (1-100) and `cursor` to page, and `sort` (prefix `-` for descending). Records also take `filter[]=value`, `filter[published_at][exists]=true` and `expand=`. ## Errors Errors share one envelope: `{ "error": { "type", "message", "request_id", "details" } }`. `details` lists field-level problems as `{ "field", "code", "message" }`. Include the `request_id` when asking for support. ## Safe retries and concurrent edits Send `Idempotency-Key` on any `POST`, `PUT`, `PATCH` or `DELETE` to make retrying it safe: the first result is stored for 24 hours and returned again for the same request. Record responses carry the record's revision as an `ETag`; send it back as `If-Match` to update only if nobody changed the record in the meantime (`412` otherwise). ## History Every change to a record is a revision, attributed to the person or API key that made it: record revisions can be listed, diffed and reverted, and collections keep a schema history. Send `Nohead-Change-Note` to record why a change was made. Changes that rewrite existing values (such as a field's type) are explicit, previewable field migrations. How long revisions are kept depends on the organization's plan. Older ones are removed, but every record keeps its first revision and its last 10; `history_pruned_through` says how far history was removed. license: name: Proprietary identifier: LicenseRef-Proprietary servers: - url: https://api.nohead.io description: Production security: - apiKey: [] tags: - name: records x-group: Records description: Content entries, one at a time or many at once. - name: publishing x-group: Publishing description: Making records live, now or at a set time, and taking them down. - name: revisions x-group: Revisions description: A record's history, comparing two revisions, and going back to one. - name: drafts x-group: Drafts description: Changes to a record that wait to be merged into it, now or at a set time. - name: collections x-group: Collections description: User-defined data models. - name: schema-changes x-group: Schema changes description: A collection's schema history, and its schema at any version. - name: fields x-group: Fields description: Field definitions of a collection. - name: migrations x-group: Field migrations description: Explicit field changes that rewrite existing record values, with previews. - name: assets x-group: Assets description: Files stored for a project, uploaded directly to storage. - name: search x-group: Search description: Full-text search in collections and across a project. - name: webhooks x-group: Webhooks description: Event notifications sent to your URLs, and the secrets that sign them. - name: deliveries x-group: Webhook deliveries description: Each event sent to a webhook, its attempts, and retrying it. - name: audit x-group: Activity log description: The append-only trail of who changed what, through which client. - name: system x-group: System description: Service status, the caller, and its feature flags. paths: /v1/migrations/{migration_id}/cancel: parameters: - $ref: '#/components/parameters/MigrationId' post: tags: - migrations summary: Cancel a field migration description: | A pending migration is cancelled at once. A running one stops at its next batch and is rolled back entirely (`cancel_requested_at` is set until then). Finished migrations cannot be cancelled (`409` with detail code `finished`). operationId: migrations_cancel parameters: - $ref: '#/components/parameters/IdempotencyKey' - $ref: '#/components/parameters/NoheadClient' responses: '200': description: The migration. content: application/json: schema: $ref: '#/components/schemas/FieldMigration' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' '409': $ref: '#/components/responses/Conflict' '429': $ref: '#/components/responses/RateLimited' x-codeSamples: - lang: typescript label: TypeScript source: | import { Nohead } from "@nohead/sdk" const nohead = new Nohead() const result = await nohead.migrations.cancel("mig_01J9ZQ3F8X") - lang: python label: Python source: | from nohead import Nohead nohead = Nohead() result = nohead.migrations.cancel("mig_01J9ZQ3F8X") - lang: ruby label: Ruby source: | require "nohead" nohead = Nohead::Client.new result = nohead.migrations.cancel("mig_01J9ZQ3F8X") components: parameters: MigrationId: name: migration_id in: path required: true schema: type: string examples: - mig_01J9ZQ3F8X5W2K7M4N6P0R1S2T IdempotencyKey: name: Idempotency-Key in: header required: false description: | A unique value (1-255 printable ASCII characters) that makes retrying this request safe. The first response (below 500) is stored for 24 hours per user or API key; retries with the same key and the same request get it again with an `Idempotent-Replayed: true` header. The same key with a different request is refused with `400`; a retry while the first request is still running gets `409`. schema: type: string minLength: 1 maxLength: 255 example: 8f14e45f-ceea-467a-9575-0f1a3f2c1d2e NoheadClient: name: Nohead-Client in: header description: >- First-party client identifier recorded in history (e.g. `cli/0.3.1`). Informational only. schema: type: string schemas: FieldMigration: type: object additionalProperties: false required: - id - object - collection_id - field_id - status - from - to - backfill - on_invalid - time_zone - records - failure - schema_change_id - cancel_requested_at - actor - via - note - request_id - created_at - started_at - completed_at properties: id: type: string examples: - mig_01J9ZQ3F8X5W2K7M4N6P0R1S2T object: const: field_migration collection_id: type: string field_id: type: string status: type: string enum: - pending - running - complete - failed - cancelled from: $ref: '#/components/schemas/FieldDefinition' to: $ref: '#/components/schemas/FieldDefinition' backfill: description: '`{"value": ...}` when missing values are filled in, otherwise null.' oneOf: - type: 'null' - type: object required: - value properties: value: {} on_invalid: type: string enum: - fail - clear time_zone: type: - string - 'null' description: >- The time zone dates were read in when `include_time` was turned off, if one was given. records: $ref: '#/components/schemas/FieldMigrationCounts' failure: description: >- Why the migration failed; null otherwise. A failed migration changed nothing. oneOf: - type: 'null' - type: object required: - message properties: message: type: string schema_change_id: type: - string - 'null' description: The `migrate_field` schema change, once complete. cancel_requested_at: $ref: '#/components/schemas/NullableTimestamp' description: When cancelling was asked for, while a running migration rolls back. actor: $ref: '#/components/schemas/Actor' via: $ref: '#/components/schemas/Via' note: type: - string - 'null' request_id: type: - string - 'null' created_at: $ref: '#/components/schemas/Timestamp' started_at: $ref: '#/components/schemas/NullableTimestamp' completed_at: $ref: '#/components/schemas/NullableTimestamp' FieldDefinition: type: object additionalProperties: false required: - type - configuration - multiple - required properties: type: $ref: '#/components/schemas/FieldType' configuration: $ref: '#/components/schemas/FieldConfiguration' multiple: type: boolean description: >- A list of distinct values (a repeated value is refused with `duplicate_value`, an empty string with `blank_value`). Not available for boolean, long_text, rich_text and json fields. required: type: boolean FieldMigrationCounts: type: object additionalProperties: false required: - total - unchanged - converted - backfilled - cleared - invalid description: >- Records by outcome, including soft-deleted records (which are converted but never backfilled). properties: total: type: integer unchanged: type: integer converted: type: integer backfilled: type: integer cleared: type: integer invalid: type: integer NullableTimestamp: type: - string - 'null' format: date-time Actor: type: object additionalProperties: false required: - type - id - name properties: type: type: string enum: - user - api_key - system id: type: - string - 'null' description: >- The user (`usr_...`) or API key (`key_...`), or null for system changes. name: type: - string - 'null' description: | Resolved when read, never stored: a user's current name (or email), "Deleted user" once they deleted their account, an API key's name, or "System". Via: type: string description: The client a change came through; `scheduler` for scheduled changes. enum: - ui - api - cli - sdk - mcp - system - scheduler Timestamp: type: string format: date-time description: ISO 8601 timestamp in UTC. examples: - '2026-09-27T12:00:00.000Z' Error: type: object additionalProperties: false required: - error properties: error: type: object additionalProperties: false required: - type - message - request_id properties: type: $ref: '#/components/schemas/ErrorType' message: type: string request_id: $ref: '#/components/schemas/RequestId' details: type: array items: $ref: '#/components/schemas/ErrorDetail' FieldType: type: string enum: - text - long_text - rich_text - integer - decimal - date - boolean - enum - asset - relation - json FieldConfiguration: description: > Type-specific options, e.g. `max_length`, `options`, `target_collection_id`, `accepted_types` (asset fields: MIME types or `type/*` wildcards that newly written values must have; any file when absent), `include_time` and `time_zone` (date fields, below), `format` (text fields, below), `unique` (text and integer fields, below), plus the options for searches with API keys: `searchable` (the search words match the field; default true for text, long_text, rich_text and enum), `filterable` and `sortable` (default false). Date fields hold a calendar date, `YYYY-MM-DD`, with no time and no time zone: returned exactly as written, so it never shows as the day before or after. With `include_time: true` they hold a moment: ISO 8601 with an offset, stored in UTC and returned in UTC, or with the offset of `time_zone` (an IANA name such as `Europe/Copenhagen`, daylight saving included) when the field has one. Input may use any offset. Changing `time_zone` never rewrites values; turning `include_time` on or off does, through a field migration. Text fields (not long text) can have a `format`: `slug` (lowercase letters, digits and single hyphens, at most 200 characters; one value per record, never a list, and always unique: a slug field has `unique: true`), `url` (an absolute `http` or `https` address) or `email`. A value that doesn't match is refused with `invalid_format`. A format sets its own length limits (254 characters for emails, 2,048 for URLs), so `min_length` and `max_length` are for plain text. Text and integer fields with one value can be `unique`: no two active records of the collection share a value (emails compare ignoring capitals; records without a value don't count). A taken value is refused with `taken` and the `record_id` that has it. Turning `unique` on is refused with `duplicate_values` while records share a value (and so is restoring a deleted unique field, `409`). A field migration to a unique field is refused with `duplicate_values` when its converted values or backfill would be shared, and fails if values written while it waits would be. anyOf: - $ref: '#/components/schemas/TextFieldConfiguration' - $ref: '#/components/schemas/LongTextFieldConfiguration' - $ref: '#/components/schemas/RichTextFieldConfiguration' - $ref: '#/components/schemas/IntegerFieldConfiguration' - $ref: '#/components/schemas/DecimalFieldConfiguration' - $ref: '#/components/schemas/DateFieldConfiguration' - $ref: '#/components/schemas/BooleanFieldConfiguration' - $ref: '#/components/schemas/EnumFieldConfiguration' - $ref: '#/components/schemas/AssetFieldConfiguration' - $ref: '#/components/schemas/RelationFieldConfiguration' - $ref: '#/components/schemas/JsonFieldConfiguration' RequestId: type: string pattern: ^req_[A-Za-z0-9]+$ examples: - req_01J9ZQ3F8X5W2K7M4N6P0R1S2T ErrorType: type: string enum: - invalid_request - authentication_error - plan_limit_exceeded - authorization_error - not_found - conflict - precondition_failed - validation_error - rate_limited - internal_error - service_unavailable ErrorDetail: type: object additionalProperties: false required: - code - message properties: field: type: string description: Key of the offending field or parameter, when applicable. code: type: string description: Machine-readable error code, e.g. `required`. message: type: string usage: type: integer description: Current usage, for `plan_limit` details. limit: type: integer description: The plan's limit, for `plan_limit` details. current_revision: type: integer description: The resource's current revision, for `revision_mismatch` details. record_id: type: string description: The record that already has the value, for `taken` details. draft_id: type: string description: The record's draft, for `draft_exists` and `draft_pending` details. TextFieldConfiguration: type: object additionalProperties: false description: Plain text up to 10,000 characters, or a `format`. properties: description: type: string maxLength: 500 description: Help text for editors. searchable: type: boolean description: >- Search words match the field, in every search (API keys, search tokens, members). Default true for text, long_text, rich_text and enum. filterable: type: boolean description: API searches can filter on it. Default false. sortable: type: boolean description: API searches can sort on it (one value only). Default false. min_length: type: integer minimum: 0 max_length: type: integer minimum: 0 format: type: string enum: - slug - url - email description: >- `slug` (always unique, one value), `url` (absolute http or https) or `email`; each sets its own length limits. unique: type: boolean description: >- No two active records of the collection share a value (one value only; a slug is always unique). LongTextFieldConfiguration: type: object additionalProperties: false description: Text up to 100,000 characters. properties: description: type: string maxLength: 500 description: Help text for editors. searchable: type: boolean description: >- Search words match the field, in every search (API keys, search tokens, members). Default true for text, long_text, rich_text and enum. filterable: type: boolean description: API searches can filter on it. Default false. sortable: type: boolean description: API searches can sort on it (one value only). Default false. min_length: type: integer minimum: 0 max_length: type: integer minimum: 0 RichTextFieldConfiguration: type: object additionalProperties: false description: >- A rich text document up to 1,000,000 bytes (`too_large`), written as Markdown or a document (see `RecordData`). properties: description: type: string maxLength: 500 description: Help text for editors. searchable: type: boolean description: >- Search words match the field, in every search (API keys, search tokens, members). Default true for text, long_text, rich_text and enum. filterable: type: boolean description: API searches can filter on it. Default false. sortable: type: boolean description: API searches can sort on it (one value only). Default false. IntegerFieldConfiguration: type: object additionalProperties: false properties: description: type: string maxLength: 500 description: Help text for editors. searchable: type: boolean description: >- Search words match the field, in every search (API keys, search tokens, members). Default true for text, long_text, rich_text and enum. filterable: type: boolean description: API searches can filter on it. Default false. sortable: type: boolean description: API searches can sort on it (one value only). Default false. min: type: integer max: type: integer unique: type: boolean description: >- No two active records of the collection share a value (one value only). DecimalFieldConfiguration: type: object additionalProperties: false properties: description: type: string maxLength: 500 description: Help text for editors. searchable: type: boolean description: >- Search words match the field, in every search (API keys, search tokens, members). Default true for text, long_text, rich_text and enum. filterable: type: boolean description: API searches can filter on it. Default false. sortable: type: boolean description: API searches can sort on it (one value only). Default false. min: type: number max: type: number DateFieldConfiguration: type: object additionalProperties: false properties: description: type: string maxLength: 500 description: Help text for editors. searchable: type: boolean description: >- Search words match the field, in every search (API keys, search tokens, members). Default true for text, long_text, rich_text and enum. filterable: type: boolean description: API searches can filter on it. Default false. sortable: type: boolean description: API searches can sort on it (one value only). Default false. include_time: type: boolean description: >- Holds a moment (ISO 8601 with an offset) instead of a calendar date; changing it is a field migration. time_zone: type: string description: >- An IANA time zone (`Europe/Copenhagen`) moments are returned in; changing it never rewrites values. BooleanFieldConfiguration: type: object additionalProperties: false properties: description: type: string maxLength: 500 description: Help text for editors. searchable: type: boolean description: >- Search words match the field, in every search (API keys, search tokens, members). Default true for text, long_text, rich_text and enum. filterable: type: boolean description: API searches can filter on it. Default false. sortable: type: boolean description: API searches can sort on it (one value only). Default false. EnumFieldConfiguration: type: object additionalProperties: false required: - options properties: description: type: string maxLength: 500 description: Help text for editors. searchable: type: boolean description: >- Search words match the field, in every search (API keys, search tokens, members). Default true for text, long_text, rich_text and enum. filterable: type: boolean description: API searches can filter on it. Default false. sortable: type: boolean description: API searches can sort on it (one value only). Default false. options: type: array minItems: 1 maxItems: 500 uniqueItems: true items: type: string minLength: 1 maxLength: 100 AssetFieldConfiguration: type: object additionalProperties: false properties: description: type: string maxLength: 500 description: Help text for editors. searchable: type: boolean description: >- Search words match the field, in every search (API keys, search tokens, members). Default true for text, long_text, rich_text and enum. filterable: type: boolean description: API searches can filter on it. Default false. sortable: type: boolean description: API searches can sort on it (one value only). Default false. accepted_types: type: array maxItems: 50 description: >- MIME types or `type/*` wildcards newly written values must have (`["image/*", "application/pdf"]`); any file when absent. items: type: string RelationFieldConfiguration: type: object additionalProperties: false required: - target_collection_id properties: description: type: string maxLength: 500 description: Help text for editors. searchable: type: boolean description: >- Search words match the field, in every search (API keys, search tokens, members). Default true for text, long_text, rich_text and enum. filterable: type: boolean description: API searches can filter on it. Default false. sortable: type: boolean description: API searches can sort on it (one value only). Default false. target_collection_id: type: string description: The collection (same project) whose records it points at. JsonFieldConfiguration: type: object additionalProperties: false description: >- Any JSON value up to 100,000 bytes (`too_large`), nested at most 32 levels deep (`too_deep`): for data with a shape of its own, such as settings or another service's payload. Content belongs in typed fields, and large data in an asset. properties: description: type: string maxLength: 500 description: Help text for editors. searchable: type: boolean description: >- Search words match the field, in every search (API keys, search tokens, members). Default true for text, long_text, rich_text and enum. filterable: type: boolean description: API searches can filter on it. Default false. sortable: type: boolean description: API searches can sort on it (one value only). Default false. responses: BadRequest: description: >- The request was malformed: unparseable JSON, an invalid query parameter, or a body key the operation doesn't take (detail code `unknown_parameter`, naming the key). headers: X-Request-Id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/Error' Unauthorized: description: Authentication is missing or invalid. headers: X-Request-Id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/Error' Forbidden: description: The caller is not allowed to perform this action. headers: X-Request-Id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/Error' NotFound: description: The resource does not exist or is not visible to the caller. headers: X-Request-Id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/Error' Conflict: description: The request conflicts with current state. headers: X-Request-Id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/Error' RateLimited: description: > Too many requests for this API key or user (or, with failing credentials, this IP address). A published-only key is counted per client IP. Wait `Retry-After` seconds; retries with the same `Idempotency-Key` are safe. On the Free plan, an organization's API keys are also refused once its API requests reach the month's limit, with a `plan_limit` detail (`field` `api_requests`, `usage` and `limit`), until the next month (UTC) or an upgrade. headers: X-Request-Id: $ref: '#/components/headers/RequestId' Retry-After: description: Seconds to wait before retrying. schema: type: integer RateLimit-Limit: $ref: '#/components/headers/RateLimitLimit' RateLimit-Remaining: $ref: '#/components/headers/RateLimitRemaining' RateLimit-Reset: $ref: '#/components/headers/RateLimitReset' content: application/json: schema: $ref: '#/components/schemas/Error' headers: RequestId: description: Unique identifier for the request, also echoed in error bodies. schema: $ref: '#/components/schemas/RequestId' RateLimitLimit: description: >- Requests allowed in the current window. Sent on every authenticated response. schema: type: integer RateLimitRemaining: description: Requests left in the current window. schema: type: integer RateLimitReset: description: Seconds until the window resets. schema: type: integer securitySchemes: apiKey: type: http scheme: bearer description: | Project-scoped API key, e.g. `nohead_sk_k7fz0a9c3m2q_`, or `nohead_pk_…` for a published-only key. Used by servers, CI, the CLI and coding agents. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.