> ## Documentation Index > Fetch the complete documentation index at: https://docs.sync2books.com/llms.txt > Use this file to discover all available pages before exploring further. # Resend the result callback > Delivers the latest result of this sale to its `callbackUrl` once, now. Use it when your endpoint was down for longer than the automatic retries last. The response says how the attempt went. It is a `404` if the sale was created without a `callbackUrl` and a `409` if the sale has no result yet. Required scope: `sales:write`. ## OpenAPI ````yaml /openapi/etims.json post /v1/sales/{id}/callback/resend openapi: 3.1.0 info: title: Sync2Books Compliance API (eTIMS) version: 1.0.0 description: >- Register items, issue sales and credit notes, record stock and read supplier invoices for a Kenyan business, with every fiscal document signed by KRA eTIMS. Authenticate with an API key from the compliance dashboard, sent in the `x-api-key` header or as a bearer token. A `cmp_sk_test_...` key acts on sandbox businesses and a `cmp_sk_live_...` key on production ones; both use the same base URL. New here? Start with the [eTIMS quickstart](/etims-quickstart). The conventions every endpoint shares are in [Authentication & API keys](/etims-authentication), [Errors & Troubleshooting](/etims-errors), [Idempotency](/etims-idempotency) and [Rate limits](/etims-rate-limits). This is a separate product from the [Accounting API](/api-reference), with its own keys. servers: - url: https://sync2books-compliance-api.apps.kintro.money description: >- Sync2Books Compliance API. The key you use decides whether a call reaches the KRA sandbox or production. security: - ApiKeyAuth: [] - BearerAuth: [] tags: - name: Identity description: Check what a key can do. - name: Businesses description: The businesses and branches a key can act for. - name: Items description: >- Create items and register them with KRA. An item must be registered before it can be sold. - name: Stock description: Record stock movements and report them to KRA. - name: Sales description: Issue sales, read them back and download KRA-signed receipts. - name: Credit notes description: Reverse an accepted sale in full. - name: Purchases description: Supplier invoices KRA holds against the business. - name: Lookups description: KRA code lists and item classifications. paths: /v1/sales/{id}/callback/resend: post: tags: - Sales summary: Resend the result callback description: >- Delivers the latest result of this sale to its `callbackUrl` once, now. Use it when your endpoint was down for longer than the automatic retries last. The response says how the attempt went. It is a `404` if the sale was created without a `callbackUrl` and a `409` if the sale has no result yet. Required scope: `sales:write`. operationId: resendCallback parameters: - $ref: '#/components/parameters/SaleId' - $ref: '#/components/parameters/BusinessId' responses: '200': description: The delivery state after the attempt. headers: X-RateLimit-Limit: $ref: '#/components/headers/RateLimitLimit' X-RateLimit-Remaining: $ref: '#/components/headers/RateLimitRemaining' X-RateLimit-Reset: $ref: '#/components/headers/RateLimitReset' content: application/json: schema: type: object required: - data properties: data: type: object properties: callback: $ref: '#/components/schemas/Callback' example: data: callback: url: https://example.com/hooks/sync2books status: delivered event: sale.completed attempts: 1 lastAttemptAt: '2026-10-02T10:16:00.000Z' lastResponseStatus: 200 lastError: null deliveredAt: '2026-10-02T10:16:00.000Z' nextAttemptAt: null '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' '409': description: The sale has no result from KRA yet. content: application/json: schema: $ref: '#/components/schemas/Error' examples: conflict: summary: conflict value: error: code: conflict message: >- This sale has no result from KRA yet; its callback is sent when it does. '429': $ref: '#/components/responses/RateLimited' components: parameters: SaleId: name: id in: path required: true description: The id of a sale or credit note, as returned in `data.sale.id`. schema: type: string BusinessId: name: businessId in: query required: false description: >- The business to act for. Required for organisation-wide keys; omit it for a business-bound key. List the ids you can use with `GET /v1/businesses`. schema: type: string headers: RateLimitLimit: description: Requests allowed per minute for your application. schema: type: integer RateLimitRemaining: description: Requests left in the current one-minute window. schema: type: integer RateLimitReset: description: >- Seconds until the current window resets. This is a number of seconds, not a Unix timestamp. schema: type: integer schemas: Callback: type: - object - 'null' description: >- Delivery state of the result callback. `null` when the sale was created without a `callbackUrl`. properties: url: type: string status: type: string enum: - awaiting_outcome - pending - delivered - failed event: type: - string - 'null' enum: - sale.completed - sale.failed - null attempts: type: integer lastAttemptAt: type: - string - 'null' format: date-time lastResponseStatus: type: - integer - 'null' lastError: type: - string - 'null' deliveredAt: type: - string - 'null' format: date-time nextAttemptAt: type: - string - 'null' format: date-time Error: type: object required: - error properties: error: type: object required: - code - message additionalProperties: true properties: code: type: string description: >- A stable, machine-readable code. Branch on this. See [Errors & Troubleshooting](/etims-errors) for the full list. examples: - invalid_request - kra_rejected - already_credited message: type: string description: >- A human-readable explanation. The wording can change; do not parse it. description: >- Some errors carry extra fields next to `code` and `message`, for example `sale`, `item`, `errors`, `creditNoteId` or `branches`. responses: Unauthorized: description: >- The key is missing, malformed, revoked, expired or belongs to a suspended application. The response never says which. content: application/json: schema: $ref: '#/components/schemas/Error' examples: invalid_api_key: summary: invalid_api_key value: error: code: invalid_api_key message: Invalid API key Forbidden: description: >- The key is valid but may not do this: a missing scope, a business the key is not limited to, or a test key used against a production business (or the reverse). content: application/json: schema: $ref: '#/components/schemas/Error' examples: missing_scope: summary: missing_scope value: error: code: forbidden message: This API key is missing the sales:write scope other_business: summary: other_business value: error: code: forbidden message: >- This API key is limited to a single business and cannot act for another one. environment_mismatch: summary: environment_mismatch value: error: code: forbidden message: >- This is a test API key and Example Business Ltd is a production business. Use the key for that environment. NotFound: description: >- The id does not exist, or belongs to another business. The two cases are deliberately indistinguishable. content: application/json: schema: $ref: '#/components/schemas/Error' examples: not_found: summary: not_found value: error: code: not_found message: Sale sale_example_9 not found RateLimited: description: >- The application has used its requests for this minute. Wait `Retry-After` seconds. headers: X-RateLimit-Limit: $ref: '#/components/headers/RateLimitLimit' X-RateLimit-Remaining: $ref: '#/components/headers/RateLimitRemaining' X-RateLimit-Reset: $ref: '#/components/headers/RateLimitReset' Retry-After: description: Seconds to wait before trying again. schema: type: integer content: application/json: schema: $ref: '#/components/schemas/Error' examples: rate_limited: summary: rate_limited value: error: code: rate_limited message: >- Rate limit of 120 requests per minute exceeded. Retry in 23s. securitySchemes: ApiKeyAuth: type: apiKey in: header name: x-api-key description: >- Your API key, for example `cmp_sk_test_xxxxxxxxxxxxxxxxxxxxxxxx`. Create one on the Integrations page of the compliance dashboard. BearerAuth: type: http scheme: bearer bearerFormat: cmp_sk_... description: >- The same key, sent as `Authorization: Bearer `. Use this if your HTTP client makes custom headers awkward. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.