> ## Documentation Index > Fetch the complete documentation index at: https://docs.melso.ai/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Melso MCP: https://mcp.melso.ai/mcp (OAuth; one company per connection). Documentation-search MCP: https://docs.melso.ai/mcp; it does not act on customer accounts. > > Use the live tool list and respect company membership. Ask the person to approve the exact invoice or tax return version in the signed-in app. Melso's professionals prepare and file included returns after approval; an AI assistant does not file. A prepared file or an approval is not evidence of filing: only the AEAT's reference and receipt are. Keep credentials out of chat and logs. # Request a certificate > Requests an official certificate for the company, such as being up to date with the AEAT or the TGSS, which lenders and public tenders ask for. **Preview.** A contract we are building with design partners. It is not callable yet, and fields can still change. See [Availability](/api/availability). Melso obtains it under the company's mandate; the certificate carries the administration's CSV (código seguro de verificación) for anyone to verify it. ## OpenAPI ````yaml api/openapi.yaml POST /companies/{company_id}/certificates openapi: 3.1.0 info: title: Melso API version: 1.0.0-preview summary: Spanish tax and labour compliance for the companies on your platform. description: | The Melso API lets an HR, payroll, banking or ERP platform run the Spanish tax and labour obligations of the companies it serves: invoices, books, tax returns, Social Security and employment notifications. Melso calculates and prepares. A person at the company approves the exact version. Melso's professionals file under the company's representation, and the filing is proven only by the administration's reference and receipt. Every operation states its availability in `x-melso-status`: - `live`: Melso runs this capability in production today. Partner keys reach it once a partner account is enabled. - `preview`: a contract proposed to design partners. Not callable yet. `x-melso-actor: person` marks a decision a signed-in person makes in Melso; a partner sends them the approval link instead. contact: name: Melso partnerships email: hello@melso.ai url: https://docs.melso.ai/api/overview servers: - url: https://api.melso.ai/v1 description: API. Keys and access are issued per partner. security: - partnerKey: [] tags: - name: Companies description: The companies you operate for, their fiscal profile and hosted onboarding. - name: Mandates description: >- The company's representation of Melso before the AEAT, the TGSS and the SEPE. - name: Webhook endpoints description: Where Melso sends signed events about your companies. - name: Invoicing setup description: Registration of the company as a VERI*FACTU or TicketBAI invoice issuer. - name: Customers description: The company's invoice customers. - name: Invoices description: >- Drafts, approval, legal registration, delivery and payment of the company's invoices. - name: Expenses description: >- Purchase invoices and receipts, with their AEAT category and deductibility. - name: Income description: Income invoiced outside Melso. - name: Documents description: >- Files the company gives Melso, and Melso's structured reading of an invoice or receipt. - name: Banking description: >- Bank accounts, movements, statements and reconciliation with invoices and expenses. - name: Accounting description: Journal, imported books and the company's financial statements. - name: Tax calendar description: The forms the company must file, with their periods and deadlines. - name: Tax returns description: The returns Melso calculates, their approval and their filing. - name: Corporate tax description: The year's corporate tax (modelo 200) and its instalments (modelo 202). - name: Tax estimates description: What the company should set aside for taxes, as of today. - name: Cases description: Gestiones, the procedures Melso's professionals carry out for the company. - name: Administration notifications description: Electronic notifications from the administration to the company. - name: Certificates description: >- Official certificates such as being up to date with the AEAT or the Social Security. - name: Employees description: The people the company employs. - name: Payroll runs description: >- The payroll results your platform calculated, for Melso to settle and declare. - name: Social Security description: >- Affiliation (altas, bajas and variaciones) and monthly contribution settlements. - name: Employment notifications description: >- Contrat@ contract notifications and Certific@2 company certificates to the SEPE. paths: /companies/{company_id}/certificates: parameters: - $ref: '#/components/parameters/CompanyId' post: tags: - Certificates summary: Request a certificate description: | Requests an official certificate for the company, such as being up to date with tax obligations (AEAT) or with the Social Security (TGSS), which lenders and public tenders ask for. Melso obtains it under the company's mandate; the certificate carries the administration's CSV (código seguro de verificación) for anyone to verify it. operationId: requestCertificate parameters: - $ref: '#/components/parameters/IdempotencyKey' requestBody: required: true content: application/json: schema: type: object required: - type additionalProperties: false properties: type: $ref: '#/components/schemas/CertificateType' purpose: type: string description: >- Why it is needed, when the administration asks for it, such as `public_procurement` or `subsidy`. responses: '201': description: The request, `pending` until the administration issues it. content: application/json: schema: $ref: '#/components/schemas/Certificate' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '409': $ref: '#/components/responses/Conflict' components: parameters: CompanyId: name: company_id in: path required: true description: >- The company's ID. Every company-scoped call works in exactly this company. schema: type: string format: uuid IdempotencyKey: name: Idempotency-Key in: header description: >- A unique key, such as a UUID, that makes a retried create safe. Reusing a key with a different body is refused. schema: type: string maxLength: 255 schemas: CertificateType: type: string enum: - aeat_tax_compliance - tgss_compliance - aeat_census_status - aeat_vat_registration description: >- `aeat_tax_compliance`: up to date with tax obligations. `tgss_compliance`: up to date with the Social Security. `aeat_census_status`: census situation. `aeat_vat_registration`: registration in the register of exporters and intra-community operators (ROI). Certificate: type: object required: - id - type - status - requested_at properties: id: type: string format: uuid type: $ref: '#/components/schemas/CertificateType' status: type: string enum: - pending - issued - negative - failed description: >- `negative`: the administration issued it as not up to date; `findings` says why. csv: type: - string - 'null' description: The código seguro de verificación. issued_at: type: - string - 'null' format: date-time findings: type: array items: type: string document: oneOf: - $ref: '#/components/schemas/Document' - type: 'null' requested_at: type: string format: date-time Document: type: object properties: id: type: string format: uuid filename: type: string content_type: type: string size_bytes: type: integer url: type: string format: uri description: A short-lived download URL. Error: type: object required: - error properties: error: type: string description: What went wrong, for a person to read. code: type: string description: >- A stable code to branch on, such as `invoicing_not_ready` or `version_conflict`. request_id: type: string description: Quote it when you contact Melso. responses: BadRequest: description: >- The request is malformed or a field is invalid. Unknown fields are refused. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: lines[0].vat_rate must be 21, 10, 4 or 0 code: invalid_invoice request_id: req_01JAB3K9X2 Unauthorized: description: The key is missing, revoked or invalid. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: invalid token code: unauthorized request_id: req_01JAB3K9X2 Conflict: description: >- The object changed or is not in a state that allows this. Read it again and decide. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: The tax return changed or is not ready for approval code: version_conflict request_id: req_01JAB3K9X2 securitySchemes: partnerKey: type: http scheme: bearer description: | Your partner secret key, `mk_live_…` for real companies or `mk_test_…` for test companies. Keep it on your servers. See [Authentication](/api/authentication). ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.