Documentation Index
Fetch the complete documentation index at: /llms.txt
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Reference for OpenCard HTTP status codes, validation errors, webhook delivery retries, and common integration gotchas when building on the EMS API.
| Code | Meaning | Fix |
|---|---|---|
400 | Bad request / validation | Check field formats (org numbers, country codes) |
401 | Invalid token | Refresh OAuth token |
403 | Missing scope | Add scope to OAuth client |
404 | Not found | Check IDs, or no access |
409 | Conflict | Duplicate (e.g. issuer transaction state ID) |
422 | Business rule | e.g. delete signed signatory |
GET .../webhooks/{id}/events200 fast| Issue | Cause | Fix |
|---|---|---|
| HTML login page instead of JSON error | Missing Accept: application/json | Send Accept: application/json on every API call |
Webhook active=false | Challenge failed | Implement HMAC challenge handler |
| No transactions | TPA not activated | Wait for issuer card confirmation |
| No transactions | PDPC not signed | Cardholder must sign consent |
| Duplicate txs | Same transaction received twice | Upsert by transaction id |
| Wrong VAT on tx | Network VAT, not merchant | Subscribe to transaction.true.vat |