Build with Free Invoice Maker

20 MCP tools. Invoice DSL. OCR, AI extraction, brand detection as microservices. Free reads, pay-per-call writes.

Quick start

Discover

curl https://freeinvoicemaker.app/.well-known/mcp.json

Read (no auth)

curl -X POST https://freeinvoicemaker.app/api/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"templates.query","params":{}}'

Create (with auth)

curl -X POST https://freeinvoicemaker.app/api/mcp \
  -H "Authorization: Bearer iv_..." \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"invoices.create","params":{"...":"..."}}'

Authentication

Method	Use case
None	Read tools: `templates.query`, `invoices.query`, `entities.query`, `iv.capabilities`
Bearer API key (`iv_...`)	Write tools. Get a key at /settings
OAuth 2.1 + PKCE	User-facing agents that act on behalf of a user
x402 USDC	Pay-per-call for compute-heavy endpoints (OCR, AI extract)

MCP tools (20)

Invoice lifecycle (8)

Tool	Auth	Description
`invoices.create`	Key	Create a new invoice
`invoices.query`	None	List and filter invoices
`invoices.mutate`	Key	Update an existing invoice
`invoices.export`	No	Export to PDF, DOCX, CSV
`invoices.send`	Key	Send invoice via email or link
`invoices.finalize`	Key	Lock invoice, assign number
`invoices.duplicate`	Key	Clone an existing invoice
`invoices.createFromDsl`	Key	Create from Invoice DSL string

AI-native (3)

Tool	Auth	Description
`invoices.summarize`	No	Natural-language invoice summary
`invoices.suggest`	Key	Smart field suggestions from context
`invoices.analytics`	Key	Revenue analytics and trends

Templates and entities (5)

Tool	Auth	Description
`templates.query`	None	List available templates
`templates.mutate`	Key	Create or update custom templates
`templates.apply`	Key	Apply template to an invoice
`entities.query`	None	List saved clients and businesses
`entities.mutate`	Key	Create or update entities

Platform (4)

Tool	Auth	Description
`import`	Key	Import from DOCX, Excel, CSV, PDF
`invoices.automate`	Key	Set up recurring invoices
`iv.capabilities`	None	List available features and limits
`iv.feedback`	No	Submit feedback programmatically

Invoice DSL

The Invoice DSL is a compact text format for describing invoices. It uses ~100 tokens compared to ~400 for equivalent JSON, making it ideal for LLM-generated invoices.

INVOICE #INV-0042
FROM: Acme Corp | acme@example.com
TO: Globex Inc | globex@example.com
DATE: 2026-04-08
DUE: Net 30

Website redesign    | 1 | $4,200
Brand assets        | 1 | $1,800
Hosting (annual)    | 1 | $480

TAX: 10%
NOTE: Payment via wire transfer preferred.

Pass this string to invoices.createFromDsl to create a complete invoice in a single call.

Paid microservices (x402)

Compute-heavy endpoints use the x402 payment protocol. Pay per call with USDC on Base.

Service	Price	Description
OCR	$0.005	Extract text from invoice images
AI extract	$0.01	Structured data extraction from documents
Brand extract	$0.01	Logo, colors, fonts from a URL or image
PDF render	$0.005	Server-side PDF generation

Network: Base (USDC). Facilitator: x402.org.

Integration recipes

Create, send, get paid — 3-call workflow: invoices.create → invoices.send → client pays via hosted link
Import and extract — 2-call workflow: import (DOCX/PDF) → invoices.create
Chain with Zapier MCP Client — connect iv to 7,000+ apps via Zapier MCP Client
Chain with Stripe MCP — payment reconciliation via Stripe MCP Server
Chain with QuickBooks MCP — sync invoices via QuickBooks Online MCP Server

SDKs and tools

Endpoint	URL	Notes
MCP	`/api/mcp`	JSON-RPC 2.0, full tool catalog
SSE streaming	`/api/mcp/stream`	Server-sent events for long-running ops
REST API	`/api/openapi.json`	OpenAPI 3.1 spec
WebMCP bridge	`window.postMessage`	For browser-based agents

Rate limits

Tier	Burst	Sustained	Daily
Anonymous	10/min	60/hr	200
Free	30/min	300/hr	1,000
Pro	120/min	2,000/hr	20,000
Team	300/min	5,000/hr	50,000
Business	600/min	10,000/hr	100,000