Documents

Submit Thai tax documents (tax invoice receipts, credit notes, debit notes) for PDF generation and INET e-Tax submission.

Document Types

`docType`	Description
`TAX_INVOICE_RECEIPT`	Combined tax invoice and receipt
`FULL_TAX_INVOICE`	Full tax invoice only
`CREDIT_NOTE`	Credit adjustment (requires original document fields)
`DEBIT_NOTE`	Debit adjustment (requires original document fields)

POST /api/v1/documents

Submit a new tax document.

POST /api/v1/documents

Headers

Header	Required	Description
`X-API-Key`	✓	Your API key
`X-Idempotency-Key`	✓	Unique key per request
`Content-Type`	✓	`application/json`

Request Body

Field	Type	Required	Description
`sourceId`	string	✓	Your source code (e.g. `TESTSRC`)
`docType`	enum	✓	One of the document types above
`documentNo`	string	✓	Your unique document number
`documentDate`	string	✓	Date in `YYYY-MM-DD` format
`pdfBase64`	string	—	Pre-generated PDF as base64. Omit to let the server generate from template
`metadata`	object	✓	See Metadata fields below

Metadata Fields

Field	Type	Required	Notes
`sellerTaxId`	string	✓	13-digit Thai tax ID
`sellerName`	string	✓	—
`sellerBranchCode`	string	✓	5-digit branch code
`sellerAddress`	string	✓	—
`buyerTaxId`	string	✓	13-digit Thai tax ID
`buyerName`	string	✓	—
`buyerBranchCode`	string	✓	5-digit branch code
`buyerAddress`	string	✓	—
`currency`	string	—	Default: `THB`
`amountExVat`	number	—	Amount excluding VAT
`vatAmount`	number	—	VAT amount
`totalAmount`	number	—	Must equal `amountExVat + vatAmount`
`lineItems`	array	—	Array of line item objects
`phone`	string	—	Buyer phone
`email`	string	—	Buyer email (valid email format)
`originalDocumentNo`	string	Credit/Debit only	Required for `CREDIT_NOTE` / `DEBIT_NOTE`
`originalDocumentDate`	string	Credit/Debit only	`YYYY-MM-DD`
`originalDocumentType`	enum	Credit/Debit only	One of the document types above
`adjustmentReason`	string	Credit/Debit only	—
`adjustedAmountExVat`	number	Credit/Debit only	—
`adjustedVatAmount`	number	Credit/Debit only	—
`adjustedTotalAmount`	number	Credit/Debit only	—

Example Request

curl -X POST https://dev-etax.siamprop.app/api/v1/documents \
  -H "X-API-Key: sk_etax_your_key" \
  -H "X-Idempotency-Key: idem-inv-2026-001" \
  -H "Content-Type: application/json" \
  -d '{
    "sourceId": "TESTSRC",
    "docType": "TAX_INVOICE_RECEIPT",
    "documentNo": "INV-2026-001",
    "documentDate": "2026-03-09",
    "metadata": {
      "sellerTaxId": "0101234567890",
      "sellerName": "ACME Co., Ltd.",
      "sellerBranchCode": "00000",
      "sellerAddress": "99 Sukhumvit Rd, Bangkok 10110",
      "buyerTaxId": "0109876543210",
      "buyerName": "Beta Corp Co., Ltd.",
      "buyerBranchCode": "00001",
      "buyerAddress": "55 Silom Rd, Bangkok 10500",
      "currency": "THB",
      "amountExVat": 1000,
      "vatAmount": 70,
      "totalAmount": 1070,
      "lineItems": [
        { "description": "Software License", "qty": 1, "unitPrice": 1000, "lineTotal": 1000 }
      ]
    }
  }'

Response — 201 Created

{
  "documentId": "01KK9PJ85APR3S0AWMCNDY6Y6Y",
  "status": "RECEIVED"
}

Response — 200 OK (idempotency replay)

Returns the same body as the original 201 response.

Error Cases

errorCode	HTTP	Cause
`UNAUTHORIZED`	401	Invalid or missing API key
`VALIDATION_ERROR`	422	Missing required fields or invalid format
`DUPLICATE_DOCUMENT`	409	`documentNo` already exists for this source
`IDEMPOTENCY_CONFLICT`	409	Same idempotency key, different request body
`PDF_GENERATION_FAILED`	422	Server-side PDF generation failed
`TEMPLATE_NOT_FOUND`	422	No active template for this `docType`

GET /api/v1/documents/:id

Retrieve a single document by its ID.

GET /api/v1/documents/{documentId}

Headers

Header	Required	Description
`X-API-Key`	✓	Your API key

Example Request

curl https://dev-etax.siamprop.app/api/v1/documents/01KK9PJ85APR3S0AWMCNDY6Y6Y \
  -H "X-API-Key: sk_etax_your_key"

Response — 200 OK

{
  "documentId": "01KK9PJ85APR3S0AWMCNDY6Y6Y",
  "sourceId": "TESTSRC",
  "docType": "TAX_INVOICE_RECEIPT",
  "documentNo": "INV-2026-001",
  "documentDate": "2026-03-09",
  "status": "ACKNOWLEDGED",
  "inetReference": "INET-REF-12345",
  "receivedAt": "2026-03-09T10:00:00.000Z",
  "acknowledgedAt": "2026-03-09T10:01:30.000Z"
}

GET /api/v1/documents

List documents for your source.

GET /api/v1/documents?sourceId=TESTSRC&page=1&limit=20

Query Parameters

Parameter	Required	Default	Description
`sourceId`	✓	—	Your source code
`status`	—	all	Filter by document status
`documentNo`	—	—	Filter by document number
`page`	—	`1`	Page number
`limit`	—	`20`	Items per page (max 100)

Response — 200 OK

{
  "items": [
    {
      "documentId": "01KK9PJ85APR3S0AWMCNDY6Y6Y",
      "docType": "TAX_INVOICE_RECEIPT",
      "documentNo": "INV-2026-001",
      "documentDate": "2026-03-09",
      "status": "ACKNOWLEDGED"
    }
  ],
  "pagination": {
    "page": 1,
    "limit": 20,
    "total": 1
  }
}