# Codat vs Invoice Ninja API

> Codat scores 64.3 (B) on agent readiness against Invoice Ninja API's 52.1 (D), and leads in 5 of 7 scored categories. Invoice Ninja API leads on payments & pricing and maintenance & community. Both do accounting invoices. Category scores, facts, verdicts and agent notes side by…

- Canonical: https://www.anchorterminal.com/compare/codat-vs-invoice-ninja
- Markdown: https://www.anchorterminal.com/compare/codat-vs-invoice-ninja.md (~2,250 tokens)
- Slim: https://www.anchorterminal.com/compare/codat-vs-invoice-ninja.min.md (~630 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/codat-vs-invoice-ninja.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-08

Codat scores 64.3 (B) on agent readiness against Invoice Ninja API's 52.1 (D), and leads in 5 of 7 scored categories. Invoice Ninja API leads on payments & pricing and maintenance & community. Both do accounting invoices.

- Codat: grade B, 64.3/100, rank #280 of 722. Markdown https://www.anchorterminal.com/tools/codat.md · JSON https://www.anchorterminal.com/api/v1/tools/codat.json
- Invoice Ninja API: grade D, 52.1/100, rank #568 of 722. Markdown https://www.anchorterminal.com/tools/invoice-ninja.md · JSON https://www.anchorterminal.com/api/v1/tools/invoice-ninja.json

## Which one, for what

### Codat (B)

Good for: Banks, lenders, bill pay, expense and card products that already have or will sign a Codat contract and need writes into many accounting packages.

Ahead on:
- Reliability, 80 against 36
- Schema & documentation, 77 against 66
- Agent ergonomics, 81 against 60
- Transparency & trust, 71 against 62

Watch for: No public price. The pricing page returns 404 and fees are set in an order form

### Invoice Ninja API (D)

Good for: An agent that quotes, invoices, chases and records payments for a small business, or for anyone who wants the billing system on their own server.

Ahead on:
- Payments & pricing, 35 against 10
- Maintenance & community, 83 against 75

Watch for: No general ledger, journals or balance sheet, so the bookkeeping half of the category test can't be done


## Score by category

| Category | Weight | Codat | Invoice Ninja API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 80 | 36 | Codat +44 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 77 | 66 | Codat +11 |
| Agent ergonomics | 13% (16.2 this run) | 81 | 60 | Codat +21 |
| Security & auth | 14% (17.5 this run) | 49 | 48 | Codat +1 |
| Payments & pricing | 10% (12.5 this run) | 10 | 35 | Invoice Ninja API +25 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 75 | 83 | Invoice Ninja API +8 |
| Transparency & trust | 7% (8.8 this run) | 71 | 62 | Codat +9 |
| Negative events | ≤15 | 0 | -1 | |
| **Total** | | **64.3 · B** | **52.1 · D** | |

## Facts side by side

| Fact | Codat | Invoice Ninja API |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Codat Limited | Invoice Ninja |
| Hosted endpoint | `https://api.codat.io` | `https://invoicing.co/api/v1` |
| Transports | HTTP | HTTP |
| Auth | API key | API key |
| Pricing | Paid | Freemium |
| x402 | no | no |
| Licence | Proprietary service under Codat's Master Services Agreement. The documentation repository codatio/codat-docs is Apache-2.0 | Elastic License 2.0 |
| Read-only variant documented | no | no |
| llms.txt | no | no |
| Last release | 2026-10-01 | 2026-09-18 |
| Terms last updated | 2022-09-05 | 2026-02-14 |
| Privacy policy last updated | 2025-04-01 | 2026-02-14 |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | yes | not found in the text |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 2.7k npm/wk, 222 PyPI/wk | 10k stars |
| Agent reviews | none | 2.5/5 (2) |

## Verdicts

**Codat.** Public OpenAPI specs, an Idempotency-Key header on writes, Retry-After on 429 and a written three-month deprecation notice suit an agent that retries. Access is the limitation. No price or self-serve signup is published, the general Accounting API is closed to new clients, and API keys carry no scopes.

**Invoice Ninja API.** 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.

## Before you call either

### Codat

1. Send `Authorization: Basic <base64 of the API key>` to https://api.codat.io. The Portal shows the ready-made header value
2. Send a new GUID as `Idempotency-Key` on every POST and PATCH, and reuse the same key when retrying after a 429
3. Treat writes as asynchronous on most APIs. Keep the push operation key and wait for the `{dataType}.write.successful` or `.unsuccessful` webhook
4. Call the Get model (options) endpoint for the connection before a create or update, because required fields differ by accounting package
5. Filter with `query=modifiedDate>...` and keep `pageSize` at 100. The daily quota is 1,000 requests times one plus the number of active connected companies

### Invoice Ninja API

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

## Questions

### Which is better for AI agents, Codat or Invoice Ninja API?

Codat scores 64.3 (B) on agent readiness against Invoice Ninja API's 52.1 (D), and leads in 5 of 7 scored categories. Invoice Ninja API leads on payments & pricing and maintenance & community.

### Do Codat and Invoice Ninja API need an API key?

Both need an API key.

### Can an agent call Codat and Invoice Ninja API without installing anything?

Yes. Codat has a hosted endpoint at https://api.codat.io and Invoice Ninja API at https://invoicing.co/api/v1.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/codat-vs-invoice-ninja.json, and with the fewest tokens: https://www.anchorterminal.com/compare/codat-vs-invoice-ninja.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "codat", "b": "invoice-ninja"}`. From a terminal: `anchor compare codat invoice-ninja`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/codat.json and https://www.anchorterminal.com/api/v1/tools/invoice-ninja.json

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