API Documentation

The InvoUno API lets you create, manage, and send professional documents programmatically. It follows REST conventions with JSON request and response bodies.

Base URL

https://invouno.com/v1

Authentication

Authenticate by including your API key in the Authorization header as a Bearer token. Get your API key from the Settings page.

curl https://invouno.com/v1/documents \
  -H "Authorization: Bearer pk_live_your_api_key_here"

Security: Never expose your API key in client-side code. Use it only in server-to-server requests.

Documents

GET /v1/documents

Retrieve a paginated list of your documents.

Query Parameters

Parameter	Type	Description
page	integer	Page number (default: 1)
per_page	integer	Items per page (max: 100, default: 25)
type	string	Filter by type: invoice, quote, receipt, purchase_order, estimate
status	string	Filter by status: draft, sent, paid, overdue, cancelled

curl "https://invouno.com/v1/documents?type=invoice&status=paid&page=1" \
  -H "Authorization: Bearer YOUR_API_KEY"

POST /v1/documents

Create a new document.

curl -X POST https://invouno.com/v1/documents \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "type": "invoice",
    "client_id": "cl_abc123",
    "currency": "USD",
    "issued_date": "2026-03-01",
    "due_date": "2026-03-31",
    "items": [
      {"title": "Website Design", "quantity": 1, "rate": 5000},
      {"title": "Hosting (Annual)", "quantity": 1, "rate": 1200}
    ],
    "tax_rate": 10,
    "notes": "Payment due within 30 days",
    "template": "modern"
  }'

GET /v1/documents/:id

Retrieve a single document by ID.

curl https://invouno.com/v1/documents/doc_abc123 \
  -H "Authorization: Bearer YOUR_API_KEY"

PUT /v1/documents/:id

Update an existing document. Only draft documents can be updated.

curl -X PUT https://invouno.com/v1/documents/doc_abc123 \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"status": "sent", "notes": "Updated payment terms"}'

DELETE /v1/documents/:id

Delete a document permanently.

curl -X DELETE https://invouno.com/v1/documents/doc_abc123 \
  -H "Authorization: Bearer YOUR_API_KEY"

GET /v1/documents/:id/pdf

Download a document as PDF.

curl https://invouno.com/v1/documents/doc_abc123/pdf \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -o invoice.pdf

Clients

GET /v1/clients

List all clients.

curl https://invouno.com/v1/clients \
  -H "Authorization: Bearer YOUR_API_KEY"

POST /v1/clients

Create a new client.

curl -X POST https://invouno.com/v1/clients \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Acme Corp",
    "email": "[email protected]",
    "company": "Acme Corporation",
    "country": "United States"
  }'

GET /v1/clients/:id

Retrieve a single client.

PUT /v1/clients/:id

Update a client.

DELETE /v1/clients/:id

Delete a client. This will not delete their documents.

Usage

GET /v1/usage

Get your current billing period usage and limits.

curl https://invouno.com/v1/usage \
  -H "Authorization: Bearer YOUR_API_KEY"

# Response
{
  "plan": "growth",
  "period": {"start": "2026-03-01", "end": "2026-03-31"},
  "documents": {"used": 142, "limit": 1000},
  "api_calls": {"used": 3420, "limit": 10000}
}

Templates

GET /v1/templates

List available document templates.

curl https://invouno.com/v1/templates \
  -H "Authorization: Bearer YOUR_API_KEY"

# Response
{
  "data": [
    {"id": "clean", "name": "Clean", "description": "Minimal and modern"},
    {"id": "modern", "name": "Modern", "description": "Bold with accent colors"},
    {"id": "classic", "name": "Classic", "description": "Traditional business style"},
    {"id": "minimal", "name": "Minimal", "description": "Ultra-clean with lots of whitespace"}
  ]
}

Error Codes

The API uses standard HTTP status codes. Errors include a JSON body with error and message fields.

Code	Meaning	Description
200	OK	Request succeeded
201	Created	Resource created successfully
400	Bad Request	Invalid or missing parameters
401	Unauthorized	Missing or invalid API key
403	Forbidden	Insufficient permissions
404	Not Found	Resource does not exist
422	Unprocessable	Validation failed
429	Rate Limited	Too many requests. Retry after the time in the Retry-After header.
500	Server Error	Internal error. Contact support if persistent.

# Error response format
{
  "error": "validation_error",
  "message": "The type field is required",
  "details": {
    "type": "This field is required"
  }
}