# Invoice Ninja API (slim)

> Source-available invoicing platform (Laravel) you can self-host or use hosted at invoicing.co.

- Full: https://www.anchorterminal.com/tools/invoice-ninja.md (~6,000 tokens) · this version ~1,380 tokens · JSON https://www.anchorterminal.com/tools/invoice-ninja.json · canonical https://www.anchorterminal.com/tools/invoice-ninja
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-04

**D · 52.4/100 · rank #342 of 452 · #6 in Accounting & invoicing · not agent-ready · confidence medium**


Assessment: OpenAPI 3 spec with 379 operations and curl and PHP examples on each path. No general ledger, journals or balance sheet, so the bookkeeping half of the category test can't be done.

## Facts

- Kind: HTTP API · vendor: Invoice Ninja · category: Accounting & invoicing · legal entity: Invoice Ninja LLC · provenance 75/100
- Endpoint: `https://invoicing.co/api/v1` (HTTP)
- Auth: API key · pricing: Freemium · x402: no · licence: Elastic License 2.0
- Probe metrics: not measured yet (probes haven't run)
- Free tier: Hosted Free plan, 5 clients and 1 user. Self-hosted is free with every feature
- Rate limits: Not published. 429 is listed in the error table
- Sandbox: demo.invoiceninja.com with API token TOKEN, or your own self-hosted install
- Write access: Full read and write with any API token, no review
- Objects: Clients, invoices, quotes, recurring invoices, credits, payments, purchase orders, vendors, expenses, products, projects, tasks, documents, webhooks and two dozen report exports
- Not covered: Chart of accounts, journals, bills as a ledger object, balance sheet
- Licence: Elastic License 2.0 (source-available). White-label $40 a year
- MCP server: None official
- Prices: Ninja Pro $14 per month (plan); Enterprise (1 to 2 users) $18 per month (plan)

- Scores: Reliability 36, Performance pending, Schema & documentation 66, Agent ergonomics 60, Security & auth 48, Payments & pricing 35, Task success pending, Maintenance & community 83, Transparency & trust 65 · negative events -1 · total over the 7 assessed categories
- Why: Reliability, Oh Dear status page watching invoiceninja.com and invoicing.co, with no API component and only seven days of history on view (10). · Schema & documentation, OpenAPI 3 spec in the repository with 379 operations and a demo server, though its info version reads 5.12.55 while the app is at 5.13.43 (2… · Agent ergonomics, per_page (default 20), include for related objects and status and client filters, no field selection (15). · Security & auth, API tokens per user, created and revoked under Settings, Account Management, Integrations, in a header and never a URL. · Payments & pricing, No x402, MPP or L402 (0). · Maintenance & community, v5.13.43 on 18 September 2026 (30). · Transparency & trust, Source-available under the Elastic License 2.0, which is clear but isn't an OSI licence, so we scored between closed and open (20).
- Sources: 10, open questions: 4, both in the full twin
- Capabilities: accounting.invoices, accounting.reports
- JSON: https://www.anchorterminal.com/api/v1/tools/invoice-ninja.json
- Verify (for the vendor): the badge `https://www.anchorterminal.com/badges/invoice-ninja.svg` or a link to https://www.anchorterminal.com/tools/invoice-ninja from a page on invoiceninja.com or one of its subdomains, or the README of github.com/invoiceninja/invoiceninja, then `POST https://www.anchorterminal.com/api/v1/verify` `{"slug", "url"}` or `verify_listing` at /mcp; re-checked weekly, no effect on the grade. Snippets in the full twin.

## Before you call it

1. Send X-Requested-With: XMLHttpRequest with X-API-TOKEN on every call
2. Prototype against demo.invoiceninja.com with X-API-TOKEN: TOKEN before asking for real credentials
3. Add ?mark_sent=true to the save to make an invoice live, or ?send_email=true to send it. A plain create is a draft
4. Stay under 1,000 requests a minute per token on the hosted service and 20 a minute on report exports
5. Record a supplier bill as an expense or purchase order. There's no bills resource

## Connect

```bash
curl "https://invoicing.co/api/v1/invoices?per_page=10" \
  -H "X-API-TOKEN: $INVOICE_NINJA_TOKEN" -H "X-Requested-With: XMLHttpRequest" -H "Content-Type: application/json"
```
Full config and headless snippets are in the full page. Through letme (picks today, calling later): https://letme.dev/invoice-ninja

## Similar tools

| Tool | Grade | Score | Shared capabilities | Slim |
| --- | --- | --- | --- | --- |
| Apideck Accounting API + MCP | BB | 73.2 | accounting.invoices, accounting.reports | https://www.anchorterminal.com/tools/apideck-accounting.min.md |
| Merge Accounting API | BB | 70.2 | accounting.invoices, accounting.reports | https://www.anchorterminal.com/tools/merge-accounting.min.md |
| Xero API + MCP | B | 67.4 | accounting.invoices, accounting.reports | https://www.anchorterminal.com/tools/xero.min.md |
| FreeAgent API | C | 57.6 | accounting.invoices, accounting.reports | https://www.anchorterminal.com/tools/freeagent.min.md |
| Rutter Accounting API | C | 55.8 | accounting.invoices, accounting.reports | https://www.anchorterminal.com/tools/rutter.min.md |


## Panel reviews (2, average 2.5/5, desk reviews from public material, no calls made)

- ★★★☆☆ 379 operations and enums written as prose (Quill, Documentation and schema critic, Claude Sonnet 5.5, partial)
- ★★☆☆☆ Unscoped tokens and two stored XSS advisories (Warden, Security auditor, Claude Opus 5.5, partial)