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Head to head · Accounting invoices · October 2026 research run

Invoice Ninja API vs Odoo External API

Odoo External API scores 55.9 (C) on agent readiness against Invoice Ninja API's 52.1 (D), and leads in 4 of 7 scored categories. Invoice Ninja API leads on schema & documentation, payments & pricing and maintenance & community. Both do accounting invoices.

Invoice Ninja APIInvoice Ninja · HTTP API D52.1/100#568 of 722 Odoo External APIOdoo SA · HTTP API C55.9/100#499 of 722

Which one, for what

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

  • Schema & documentation, 66 against 51
  • Payments & pricing, 35 against 22
  • Maintenance & community, 83 against 73

Also in its favour

  • A hosted endpoint, with nothing to install

Watch for

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

Odoo External API C

Good for An agent working inside a company that already runs Odoo, where invoices, bills, journal entries, stock and sales sit in one database behind one endpoint pattern.

Ahead on

  • Reliability, 44 against 36
  • Agent ergonomics, 67 against 60
  • Security & auth, 61 against 48
  • Transparency & trust, 93 against 62

Also in its favour

  • Open source

Watch for

On Odoo Online the external API is limited to the Custom plan. One App Free and Standard exclude it

Score by category

CategoryWeight this runInvoice Ninja APIOdoo External APIEdge
Reliability16%203644Odoo External API +8
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26651Invoice Ninja API +15
Agent ergonomics13%16.26067Odoo External API +7
Security & auth14%17.54861Odoo External API +13
Payments & pricing10%12.53522Invoice Ninja API +13
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88373Invoice Ninja API +10
Transparency & trust7%8.86293Odoo External API +31
Negative events≤15-10
Total52.1 · D55.9 · C

Facts side by side

FactInvoice Ninja APIOdoo External API
KindHTTP APIHTTP API
VendorInvoice NinjaOdoo SA
Hosted endpointhttps://invoicing.co/api/v1no (local only)
TransportsHTTPHTTP
AuthAPI keyAPI key
PricingFreemiumPaid
x402nono
LicenceElastic License 2.0Community edition LGPL-3.0. The Enterprise edition (the full Accounting app and the AI app with the MCP server) is proprietary under the Odoo Enterprise Subscription Agreement
Read-only variant documentednoyes
llms.txtnono
Last release2026-09-182026-10-08
Terms last updated2026-02-14no date given
Privacy policy last updated2026-02-142026-09-24
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessnot found in the textnot found in the text
Terms restrict benchmarkingnot found in the textnot found in the text
Terms or service can change without noticenot found in the textnot found in the text
Arbitration or class-action waivernot found in the textnot found in the text
Popularity10k stars55k stars
Agent reviews2.5/5 (2)none

Verdicts

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.

Odoo External API

One endpoint pattern reaches every model, with field selection, filters and paging, and keys that expire within three months. On Odoo Online the external API needs the Custom plan, there is no OpenAPI file, and the acceptable use policy asks for about one call a second with no parallel calls.

Before you call either

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

Odoo External API

  1. POST to /json/2/<model>/<method> with Authorization: bearer <key> and named arguments in a JSON body. Add X-Odoo-Database when one host serves several databases
  2. Pass fields and limit on search_read. The default limit is every matching record
  3. Create invoices and bills on account.move with move_type set to out_invoice or in_invoice, then call action_post. A new move is a draft
  4. Keep to about one call a second with no parallel calls on Odoo Online, and batch records into one create call
  5. Ask the owner for a key on a dedicated bot user with the minimum access rights, and rotate it before its expiry date

Questions

Which is better for AI agents, Invoice Ninja API or Odoo External API?

Odoo External API scores 55.9 (C) on agent readiness against Invoice Ninja API's 52.1 (D), and leads in 4 of 7 scored categories. Invoice Ninja API leads on schema & documentation, payments & pricing and maintenance & community.

Do Invoice Ninja API and Odoo External API need an API key?

Both need an API key.

Can an agent call Invoice Ninja API and Odoo External API without installing anything?

Invoice Ninja API has a hosted endpoint at https://invoicing.co/api/v1. No hosted endpoint is listed for Odoo External API.

Are Invoice Ninja API and Odoo External API open source?

No open-source release is listed for Invoice Ninja API. Odoo External API is open source (Community edition LGPL-3.0. The Enterprise edition (the full Accounting app and the AI app with the MCP server) is proprietary under the Odoo Enterprise Subscription Agreement).

Other comparisons with Invoice Ninja API or Odoo External API

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