Build invoicing into anything you ship.
Create clients, generate invoices, send PDFs, mark them paid, all via a clean REST API. Free test mode on every plan, including FREE.
Quickstart
Three curl calls to a working invoice. Replace $KEY with your test key.
curl -X POST https://hisabi.ai/api/v1/clients \
-H "Authorization: Bearer $KEY" \
-H "Content-Type: application/json" \
-d '{
"name": "Acme Inc.",
"email": "billing@acme.com",
"currency": "AED"
}'curl -X POST https://hisabi.ai/api/v1/invoices \
-H "Authorization: Bearer $KEY" \
-H "Content-Type: application/json" \
-d '{
"client_id": "<id from step 1>",
"due_date": "2026-12-01T00:00:00Z",
"currency": "AED",
"line_items": [
{
"description": "Web design",
"quantity": 1,
"unit_price": 500000,
"tax_rate": 5
}
]
}'curl https://hisabi.ai/api/v1/invoices/<id>/pdf \
-H "Authorization: Bearer $KEY"
# Returns: { "data": { "url": "...", "expires_at": "..." } }
# Fetch the URL within 5 minutes for the PDF bytes.curl -X POST https://hisabi.ai/api/v1/invoices/<id>/mark-paid \
-H "Authorization: Bearer $KEY"Keys prefixed hsb_test_ are unlimited and free on every plan. Test invoices are flagged test_mode: true, excluded from billing/analytics, and never email your clients.
Use them for development, demos, CI checks, sandboxes, anything but production.
Test invoices auto-expire and are deleted 30 days after creation. Live invoices are never deleted.
- FREE · 20 req/min, 500/day, 1 key
- STARTER · 60 req/min, 5k/day, 3 keys
- PROFESSIONAL · 120 req/min, 25k/day, 10 keys
- FIRM · 300 req/min, 100k/day, 25 keys
- All responses include
RateLimit-*headers.
Connect Hisabi to your AI assistant
Hisabi speaks the Model Context Protocol. Point any MCP-compatible AI client (Claude Desktop, Cursor, ChatGPT connectors) at https://hisabi.ai/api/mcp with your Bearer API key and the assistant can manage clients and invoices for you. No install required.
{
"hisabi": {
"url": "https://hisabi.ai/api/mcp",
"headers": {
"Authorization": "Bearer hsb_test_…"
}
}
}Use a hsb_test_ key while you wire things up. Test invoices are free, uncapped, and never email your clients, perfect for letting an AI agent experiment.
Each tool is gated by your key's scopes, so a read-only key only exposes read tools.
list_clientsList clients in the workspaceget_clientFetch a single client by idcreate_clientCreate a new clientlist_invoicesList invoices, filter by status / client / test modeget_invoiceFetch a single invoice by idcreate_invoiceCreate an invoice (live or test mode)send_invoiceSend or resend an invoice to its clientmark_invoice_paidMark an invoice as paidget_invoice_pdfReturn a short-lived pre-signed PDF URLbatch_create_invoicesCreate up to 100 invoices, per-row results
FAQ
Developer API questions
Can't find what you're looking for? Contact us
Yes. The Free plan includes API access with 1 active key, 20 requests/min, and 500 requests/day, plus unlimited free test-mode keys for development, demos, and CI. Paid plans simply lift the rate limits and key count, the API itself is free to use on every tier.
Hisabi.ai ships a stable REST API at /api/v1 with bearer-key authentication, OpenAPI 3.1 spec, snake_case JSON, integer money fields in smallest currency units, IETF rate-limit headers, request IDs on every response, and an interactive Scalar reference at /developers. Workspace-scoped keys with granular scopes (clients:read, invoices:write, brand:write, etc.) and unlimited free test mode (hsb_test_* keys) let developers build, demo, and run CI without ever burning a real invoice.
Yes. Stripe Invoicing charges 0.4% per invoice plus standard Stripe processing fees. Hisabi.ai charges nothing per invoice on the API, only the flat plan price (Free, Starter, Professional, or Firm), and the Free plan already includes production API access. For non-US businesses, Hisabi.ai is significantly cheaper than Stripe Invoicing, QuickBooks Online API, Xero API, or FreshBooks API.
Send Authorization: Bearer hsb_(live|test)_<32 hex>. Generate a key in Settings → API Keys; the raw key is shown to you once and stored only as a SHA-256 hash. The hsb_live_ / hsb_test_ prefix is a Stripe-style convention so GitHub secret scanning detects leaks automatically.
Keys prefixed hsb_test_ are unlimited and free on every plan. They produce real Invoice rows flagged test_mode: true, but those invoices are excluded from analytics, the monthly invoice cap, and outbound emails. Test mode is the recommended way to develop, demo, and run integration tests.
Test invoices auto-expire 30 days after creation. A daily cleanup job deletes them along with their line items and audit log rows. Live (production) invoices are never deleted. This keeps the FREE tier sustainable: developers get unlimited test mode, but storage growth stays bounded.
Any ISO-4217 currency. Pass currency: 'AED' / 'USD' / 'EUR' / 'GBP' / 'SAR' / 'INR' / etc. on the invoice. Money fields are integers in the smallest unit of the currency (fils for AED, cents for USD). Multi-currency invoices include automatic base-currency conversion at post time.
Yes. The full OpenAPI 3.1 spec is publicly available at https://hisabi.ai/api/v1/openapi.json and renders interactively at https://hisabi.ai/developers via Scalar. You can import it into Postman, Insomnia, Bruno, or auto-generate SDKs in any language using openapi-generator, Stainless, or Speakeasy.
Yes. Any HTTP-capable automation tool works today: Zapier 'Webhooks by Zapier', Make 'HTTP' module, n8n 'HTTP Request' node, Pipedream. Native first-party integrations for Zapier and Make are on the v1.1 roadmap.
Yes. Hisabi.ai exposes a remote Model Context Protocol (MCP) server at https://hisabi.ai/api/mcp using Streamable HTTP. Point any MCP-compatible AI client (Claude Desktop, Cursor, ChatGPT connectors) at that URL with your Bearer API key and the assistant can list and create clients, create/send/mark-paid invoices, fetch PDF URLs, and batch-create, all gated by the key's scopes. No install required. Use a hsb_test_ key to let the AI experiment safely.
API reference
Full reference rendered from the OpenAPI 3.1 spec. Try requests directly from the browser using a test key.