---
title: "T254 · ISO 20022 Cross-Rail Message Compatibility Checker — AINumbers.co"
method: POST
path: "/v1/tools/iso20022_cross_rail_compatibility"
---

# T254 · ISO 20022 Cross-Rail Message Compatibility Checker — AINumbers.co

`POST /v1/tools/iso20022_cross_rail_compatibility`

## Request

- Base URL: `https://ainumbers.co`
- URL: `https://ainumbers.co/v1/tools/iso20022_cross_rail_compatibility`
- Auth: none declared

Check ISO 20022 message compatibility across real-time payment rail implementations: FedNow, RTP/TCH, SEPA Instant, Faster Payments, PIX, PayNow. Field-level diff report and Policy Mandate routing policy. Client-side. Works offline. Zero PII.

**Tool URL:** https://ainumbers.co/tools/254-iso20022-cross-rail-compatibility.html
**AP2/Policy Mandate export:** yes

## Request body

- object
  - `message_type` 'pacs.008' | 'pacs.002' | 'pacs.004' | 'camt.056', required: ISO 20022 message type to check compatibility for
  - `source_rail` 'fednow' | 'rtp' | 'sepa_inst' | 'fps' | 'pix' | 'paynow', required: Originating real-time payment rail
  - `target_rails` string[], required: One to four destination rails to check compatibility against

## Response `200`

Successful tool execution result

- object
  - `fields_checked` integer, required
  - `fields_fully_compatible` integer
  - `fields_overlay_required` integer
  - `fields_partial` integer
  - `fields_absent` integer
  - `compatibility_pct` number, required
  - `high_severity_differences` integer
  - `high_diff_fields` string[]
  - `routing_recommendation` string, required
  - `agent_instructions` string[], required
  - `ap2_mandate` object, required

---

[API](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite.md) · [All operations](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/llms.txt) · [OpenAPI document](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/revisions/b462e4f5bb28?raw)