> ## Documentation Index > Fetch the complete documentation index at: https://invoiceapi.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Serve a how-to guide as markdown. ## OpenAPI ````yaml /api-reference/openapi.json get /docs/guides/{slug} openapi: 3.1.0 info: title: Invoice API description: >- Mexican CFDI 4.0 invoicing API. Versioned via the Invoice-Version header; current: 2026-07-15. See GET /v1/versions. version: 0.1.0 servers: - url: https://api.newinvoice.dev description: Production - url: http://localhost:3000 description: Local development security: - bearerAuth: [] tags: - name: api_keys description: Platform API-key lifecycle (create, list, revoke) - name: accounts description: 'Connect: platform-owned connected accounts (multi-tenant)' - name: fiscal_profiles description: Emitter RFC + CSD/FIEL registration - name: invoices description: Create, stamp, cancel CFDI 4.0 invoices - name: validations description: Validate arbitrary CFDI XML - name: downloads description: SAT descarga masiva jobs - name: webhook_endpoints description: HMAC-signed event delivery - name: events description: Event log - name: balance description: Remaining stamp credits - name: usage description: Metered usage records (stamps consumed) - name: catalogs description: SAT reference catalogs (uso CFDI, payment forms/methods, tax regimes, …) - name: docs description: Served documentation (error catalog + guides) paths: /docs/guides/{slug}: get: tags: - docs summary: Serve a how-to guide as markdown. parameters: - schema: type: string in: path name: slug required: true responses: '200': description: Default Response headers: Request-Id: $ref: '#/components/headers/RequestId' Invoice-Version: $ref: '#/components/headers/InvoiceVersionResponse' traceparent: $ref: '#/components/headers/Traceparent' '401': description: Missing or invalid API key. content: application/problem+json: schema: $ref: '#/components/schemas/Problem' example: type: https://errors.invoiceapi.mx/auth_unauthorized title: Authentication required status: 401 code: auth.unauthorized detail: Missing or invalid API key. remediation: >- Send `Authorization: Bearer sk_test_...` (or sk_live_...) with a valid API key. doc_url: /docs/errors#auth-unauthorized request_id: req_2P9K3sample headers: Request-Id: $ref: '#/components/headers/RequestId' Invoice-Version: $ref: '#/components/headers/InvoiceVersionResponse' traceparent: $ref: '#/components/headers/Traceparent' '404': description: Resource not found in this org + mode. content: application/problem+json: schema: $ref: '#/components/schemas/Problem' example: type: https://errors.invoiceapi.mx/resource_not_found title: Resource not found status: 404 code: resource.not_found detail: No such id in this org + mode. remediation: >- Verify the id and that the key mode (test/live) matches the id. doc_url: /docs/errors#resource-not_found request_id: req_2P9K3sample headers: Request-Id: $ref: '#/components/headers/RequestId' Invoice-Version: $ref: '#/components/headers/InvoiceVersionResponse' traceparent: $ref: '#/components/headers/Traceparent' '422': description: Request validation failed. content: application/problem+json: schema: $ref: '#/components/schemas/Problem' example: type: https://errors.invoiceapi.mx/request_validation_failed title: Request validation failed status: 422 code: request.validation_failed detail: One or more fields did not satisfy the schema. remediation: Fix the fields listed in `errors` and resubmit. doc_url: /docs/errors#request-validation_failed request_id: req_2P9K3sample headers: Request-Id: $ref: '#/components/headers/RequestId' Invoice-Version: $ref: '#/components/headers/InvoiceVersionResponse' traceparent: $ref: '#/components/headers/Traceparent' '500': description: Internal server error. content: application/problem+json: schema: $ref: '#/components/schemas/Problem' example: type: https://errors.invoiceapi.mx/internal_error title: Internal server error status: 500 code: internal.error detail: An unexpected error occurred. remediation: >- Retry later; contact support with the request_id if it persists. doc_url: /docs/errors#internal-error request_id: req_2P9K3sample headers: Request-Id: $ref: '#/components/headers/RequestId' Invoice-Version: $ref: '#/components/headers/InvoiceVersionResponse' traceparent: $ref: '#/components/headers/Traceparent' security: [] components: headers: RequestId: description: >- Unique id for this request. Also the `request_id` in every error body — log it and quote it to support; idempotency keys off it too. schema: type: string example: req_2P9K3sample InvoiceVersionResponse: description: >- The dated API version resolved for this request (request header → key pin → current). Echoed on every response. schema: type: string example: '2026-07-15' Traceparent: description: >- W3C Trace Context. When you send a valid `traceparent`, the response continues the trace (same trace-id, a fresh span-id, sampled flag). schema: type: string example: 00-0af7651916cd43dd8448eb211c80319c-b7ad6b7169203331-01 schemas: Problem: type: object description: RFC 9457 problem+json error with agent-first extensions. properties: type: type: string format: uri title: type: string status: type: integer code: type: string description: Stable dotted machine code to switch on. detail: type: string remediation: type: string description: Actionable next step for a human or agent. request_id: type: string pac: type: object properties: provider: type: string codigo: type: string mensaje: type: string errors: type: array items: type: object properties: field: type: string message: type: string required: - type - title - status - code - request_id securitySchemes: bearerAuth: type: http scheme: bearer description: 'API key: `Authorization: Bearer sk_test_...` or `sk_live_...`.' ````