Belvo vs Teller

Belvo

Belvo publishes a 146-operation OpenAPI file, an llms.txt with a Markdown twin of each docs page, and list endpoints with field selection and pages of up to 1,000. Production access needs a sales meeting, a certification call and a paid plan from 1,000 USD a month, and no changelog or maintained SDK was found.

Teller

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

Belvo

1. Send HTTP Basic with secretId as username and secretPassword as password to https://sandbox.belvo.com, and switch to https://api.belvo.com only with production keys
2. Create links through the Hosted Widget with a token from POST /api/token/, which expires after 10 minutes
3. Read stored data with GET list calls. Each POST retrieval in Brazil counts against monthly Open Finance limits, such as 8 a month per CPF for owners and accounts
4. Retry 50x responses up to five times from a 3 second base with a factor of two, and don't retry 40x apart from too_many_sessions
5. Send Belvo-Idempotency-Key with a UUID when creating a payment intent, and X-Belvo-Request-Mode: async on link deletion to avoid the limit of 5 deletions a minute

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