API Overview

The SpeyBooks API is a RESTful API that uses JSON for request and response bodies.

Base URL

https://api.speybooks.com/v1

All endpoints are relative to this base URL.

Core resources

Resource	Description
Invoices	Sales invoices and credit notes
Contacts	Customers and suppliers
Transactions	Ledger entries
Accounts	Chart of accounts
Reports	P&L, Balance Sheet, VAT

Request format

Headers

All requests require:

Authorization: Bearer sk_live_your_api_key
Content-Type: application/json

Amounts

All monetary values are integers in the smallest currency unit:

Currency	Unit	Example
GBP	Pence	150000 = £1,500.00
USD	Cents	150000 = $1,500.00
EUR	Cents	150000 = €1,500.00

Dates

Dates use ISO 8601 format:

2026-01-31           # Date only
2026-01-31T14:30:00Z # Date and time (UTC)

Response format

Success responses

{
  "id": "inv_abc123",
  "number": "INV-0001",
  "status": "draft",
  "total": 150000,
  "created_at": "2026-01-31T14:30:00Z"
}

List responses

{
  "data": [
    { "id": "inv_abc123", ... },
    { "id": "inv_def456", ... }
  ],
  "has_more": true,
  "next_cursor": "inv_def456"
}

Error responses

{
  "error": {
    "code": "validation_error",
    "message": "The 'amount' field must be a positive integer",
    "field": "amount"
  }
}

HTTP methods

Method	Usage
GET	Retrieve resources
POST	Create resources
PUT	Update resources (full replacement)
PATCH	Update resources (partial)
DELETE	Remove resources

Common patterns

Filtering

GET /v1/invoices?status=sent&contact_id=cont_abc123

Sorting

GET /v1/invoices?sort=-created_at  # Descending
GET /v1/invoices?sort=created_at   # Ascending

Pagination

GET /v1/invoices?limit=20&cursor=inv_abc123

See Pagination for details.

Versioning

The API version is included in the URL path (/v1). Breaking changes will be introduced in new versions (/v2).

Non-breaking changes (new fields, new endpoints) may be added to existing versions.

SDKs

Official SDKs are planned for:

• Node.js
• Python
• Go

For now, use any HTTP client with the REST API directly.