Powens vs Teller

Powens

Powens documents a REST API with Markdown docs, cursor pagination, date filters and a hard-delete call for connections, under a French payment institution licence. No OpenAPI file, public price, status page, idempotency key or server SDK was found, and live access needs a signed purchase order.

Teller

Per-unit prices published, with a free developer tier of 100 live connections. US only.

Powens

1. Ask the owner for the domain name, client ID and client secret from the console. Every call goes to https://{domain}.biapi.pro/2.0
2. Send limit on every transactions list. It is required, at most 1,000, and the next page comes from _links.next.href used as given
3. Enable an account with POST and {"disabled": false} only after the account holder consents. Accounts arrive disabled with no transactions
4. Store the permanent user token as a secret. It does not expire, and the default webhook sends it in the Authorization header
5. Stay under 30 calls a minute in the sandbox and use webhooks in place of polling, as the fair usage policy asks

Teller

1. In sandbox call https://api.teller.io/accounts with -u "$TELLER_ACCESS_TOKEN:" and no certificate; add the client certificate only for development and production
2. On a 404 enrollment.disconnected.* code, stop and send the user back through Teller Connect in update mode; retrying won't help
3. Pin the Teller-Version header so a dashboard upgrade doesn't change response shapes under you
4. Widen transaction syncs 7 to 10 days past the last sync to catch pending items that change date
5. Send an Idempotency-Key on every payment request; keys are kept for 72 hours