> ## Documentation Index > Fetch the complete documentation index at: https://docs.lithoblocks.com/llms.txt > Use this file to discover all available pages before exploring further. # Expire a sent message now > The event hook: expire the message at once, e.g. when the incident it announced resolves. It is replaced with the expiry notice (or deleted) before this returns. Expiring a message that already expired succeeds. If Slack refuses for now, the expiry stays due and is retried within minutes; its buttons already do nothing. ## OpenAPI ````yaml /api-reference/openapi.json post /v1/messages/{id}/expire openapi: 3.0.0 info: version: 0.0.1 title: LithoBlocks API description: >- Manage templates, compile and send Slack messages, schedule delivery, build batch digests, and configure interactive workflows. Use /v1 paths and snake_case request fields. Authenticate with an organization-scoped API key in the Authorization: Bearer header. Each operation documents its required scope; a key without it receives 403 and required_scopes. A user's organization role limits which scopes a key can receive. Compiling and sending require messages:create; read access alone does not allow either operation. Create and manage keys in Integrations → API Keys. Store credentials in a secret manager, grant only the scopes needed, and use separate keys for each environment. Resources and credentials do not transfer between environments. Use code and request_id to diagnose API errors. The error field can be a string or a schema-validation object; consult the endpoint response schema for details. Resource list endpoints document their pagination and compatibility fields individually. See the documentation guides for API key lifecycle, the complete scope/role matrix, environment availability, input-schema discovery, and idempotent sending. The endpoint definitions below are the source for request and response contracts. contact: name: LithoBlocks url: https://lithoblocks.com email: support@lithoblocks.com servers: - url: https://api.lithoblocks.com description: Production (paths in this spec are rooted at /v1/...) - url: http://localhost:9999 description: Local dev (paths in this spec are rooted at /v1/...) security: [] paths: /v1/messages/{id}/expire: post: tags: - Messages summary: Expire a sent message now description: >- The event hook: expire the message at once, e.g. when the incident it announced resolves. It is replaced with the expiry notice (or deleted) before this returns. Expiring a message that already expired succeeds. If Slack refuses for now, the expiry stays due and is retried within minutes; its buttons already do nothing. parameters: - schema: type: string format: uuid required: true name: id in: path - schema: type: string minLength: 1 maxLength: 255 description: >- Any unique string (a UUID is fine). Repeating a request with the same key and body within 24 hours replays the original response with `Idempotency-Replayed: true` instead of running again; the same key with a different body is a 409. Incomplete and 5xx outcomes are retained for reconciliation beyond 24 hours. Applies only on the documented endpoints. Never automatically change keys to bypass an uncertain outcome. example: 3f7d2c1a-9b4e-4f0a-8c6d-2e1b5a7c9d10 required: false in: header name: Idempotency-Key requestBody: required: false content: application/json: schema: type: object properties: mode: type: string enum: - replace - delete description: Defaults to the pending expiry's mode, else `replace`. retain_content: type: boolean description: >- Defaults to the pending expiry's choice, else `false`: LithoBlocks' copies are cleared. additionalProperties: false responses: '200': description: The message, expired content: application/json: schema: $ref: '#/components/schemas/SentMessageExpireResult' '400': description: '`invalid_request`: an edit with nothing to change' content: application/json: schema: $ref: '#/components/schemas/ApiError' '401': description: Authentication required content: application/json: schema: $ref: '#/components/schemas/ApiError' '402': description: >- `insufficient_credits` or `overage_limit_exceeded`: a re-render uses one credit content: application/json: schema: $ref: '#/components/schemas/ApiError' '403': description: >- Insufficient scope, or `not_message_sender`: members change only the messages they sent content: application/json: schema: $ref: '#/components/schemas/ApiError' '404': description: Message not found in your organization content: application/json: schema: $ref: '#/components/schemas/ApiError' '409': description: >- `message_not_live`, `expiration_in_progress`, `no_expiration`, `mutation_in_progress` or `reconciliation_required`; also an Idempotency-Key conflict, or `slack_not_connected` content: application/json: schema: $ref: '#/components/schemas/ApiError' '422': description: >- Validation failed, or `expiration_in_past`: an expiry must be at least 60 seconds away content: application/json: schema: anyOf: - $ref: '#/components/schemas/ValidationError' - $ref: '#/components/schemas/ApiError' '429': description: Rate limited content: application/json: schema: $ref: '#/components/schemas/ApiError' '500': description: Internal error content: application/json: schema: $ref: '#/components/schemas/ApiError' '502': description: >- `slack_refused`: Slack refused the change and nothing changed; `details` carries Slack's error content: application/json: schema: $ref: '#/components/schemas/ApiError' '503': description: >- `rate_limited`: Slack is rate limiting changes; retry after the Retry-After header content: application/json: schema: $ref: '#/components/schemas/ApiError' '504': description: >- `slack_outcome_unknown`: the change may or may not have happened; the message now needs reconciliation content: application/json: schema: $ref: '#/components/schemas/ApiError' security: - bearerAuth: - messages:update components: schemas: SentMessageExpireResult: type: object properties: outcome: type: string enum: - expired - already_expired message: $ref: '#/components/schemas/SentMessage' required: - outcome - message ApiError: type: object properties: error: type: string description: Human-readable summary. Not stable; match on `code`. code: $ref: '#/components/schemas/ErrorCode' request_id: type: string description: >- Echoed from the request's X-Request-Id header, or generated. Quote it in support requests. message: type: string details: type: string error_details: type: string success: type: boolean enum: - false valid: type: boolean enum: - false required_scopes: type: array items: type: string user_scopes: type: array items: type: string required: - error - code - request_id ValidationError: type: object properties: success: type: boolean enum: - false error: type: object properties: issues: type: array items: type: object properties: code: type: string path: type: array items: anyOf: - type: string - type: number message: type: string required: - code - path - message name: type: string required: - issues - name message: type: string description: >- The issues as one line, `path: message; path: message`, for callers that show a string (form builders such as Make) code: type: string enum: - validation_failed request_id: type: string required: - success - error - message - code - request_id SentMessage: type: object properties: id: type: string format: uuid description: >- LithoBlocks' id for the message; send responses return it as `message_id`. template_id: type: string nullable: true format: uuid description: Null once the template has been deleted. template_name: type: string nullable: true description: The template's name when the message was sent. template_version_id: type: string nullable: true format: uuid workspace_id: type: string description: The Slack workspace (team) id. channel_id: type: string nullable: true description: The resolved channel; a `D…` id for a direct message. channel_name: type: string nullable: true description: >- The channel's name when the message was sent, without the #. Null for direct messages, private channels and messages sent before 2026-10-22. message_ts: type: string description: Slack's timestamp for the message. recipient_email: type: string nullable: true recipient_slack_id: type: string nullable: true sent_at: type: string sent_by: type: string format: uuid description: The user the send is attributed to; for an API key, the key's owner. sender_api_key_id: type: string nullable: true format: uuid sender_client_id: type: string nullable: true description: The OAuth client a session token was issued to, e.g. an MCP client. source: type: string nullable: true enum: - api - api_bulk - web - scheduled - digest - slash description: How it was sent. Null for messages sent before 2026-10-22. reference: type: string nullable: true description: The caller's own handle for the message, if it gave one. lifecycle: type: string enum: - live - deleted - expired description: What has happened to the message in Slack since it was sent. revision: type: integer description: >- Increments with every change; a change names the revision it was made against. edited_at: type: string nullable: true deleted_at: type: string nullable: true expired_at: type: string nullable: true change_state: type: string enum: - idle - in_progress - needs_reconciliation description: >- `needs_reconciliation`: Slack's answer to a change was lost, and a person must say whether it went through before anything else can change. pending_action: type: string nullable: true enum: - edit - rerender - interaction_update - delete - expire fallback_text: type: string nullable: true description: The notification text sent with the blocks. text_editable: type: boolean description: >- Whether the stored blocks are exactly what Slack holds, so the text can be corrected in place. expiration: $ref: '#/components/schemas/SentMessageExpiration' required: - id - template_id - template_name - template_version_id - workspace_id - channel_id - channel_name - message_ts - recipient_email - recipient_slack_id - sent_at - sent_by - sender_api_key_id - sender_client_id - source - reference - lifecycle - revision - edited_at - deleted_at - expired_at - change_state - pending_action - fallback_text - text_editable - expiration ErrorCode: type: string enum: - unauthenticated - invalid_token - insufficient_scope - access_denied - validation_failed - invalid_request - invalid_data - invalid_destination - invalid_search_query - not_found - template_not_found - version_not_found - organization_not_found - entity_not_found - field_not_found - user_not_found - profile_not_found - credits_not_found - insufficient_credits - overage_limit_exceeded - credit_deduction_failed - compilation_failed - no_blocks_to_send - slack_not_connected - slack_user_not_found - slack_dm_failed - slack_token_decrypt_failed - slack_api_error - already_exists - invitation_pending - idempotency_conflict - idempotency_in_progress - rate_limited - tier_limit - invalid_state - template_archived - template_in_use - template_not_activated - current_version_changed - message_not_found - not_message_sender - revision_conflict - message_not_live - mutation_in_progress - reconciliation_required - nothing_to_reconcile - text_not_editable - slack_refused - slack_outcome_unknown - expiration_in_past - expiration_in_progress - no_expiration - expiration_exceeds_maximum - maintenance - misconfigured - internal_error description: >- Machine-readable reason for the failure. Match on this, not on `error`. New codes may be added; existing ones are stable. SentMessageExpiration: type: object nullable: true properties: expires_at: type: string mode: type: string enum: - replace - delete description: >- `replace` (default): the message is replaced with a notice that it expired, and its buttons stop working. `delete`: it is deleted from Slack. state: type: string enum: - scheduled - processing - completed - failed - cancelled description: >- `failed`: the expiry gave up after its retries (see `last_error`); the message's buttons still do nothing after the deadline. retain_content: type: boolean description: >- Whether LithoBlocks keeps its copies of what the message said after it expires. attempts: type: integer last_error: type: string nullable: true completed_at: type: string nullable: true required: - expires_at - mode - state - retain_content - attempts - last_error - completed_at description: The message's expiry, if one was ever set. securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: API Key description: >- LithoBlocks API key obtained from your organization dashboard. The LithoBlocks MCP server also presents a Supabase-issued user session token here on the user's behalf; such a token acts as that user with the scopes their organization role allows. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.