Why this exists
Building ramp and bank-linking flows from scratch means a separate KYC review per provider, per-region payment rail integrations, and ongoing institution coverage. Meld consolidates those into one provider. You call the Sumvin Platform API — ramp sessions, linked accounts, institution discovery — and the user stays inside a single hosted widget for every payment and bank-connect flow.What ships today
| Slice | Status | What it covers |
|---|---|---|
| KYC passthrough | Shipped | Your KYC-verified user does not re-verify inside a Meld widget. |
| Bank linking | Shipped | Link a user’s bank account through a hosted Meld institution-connect flow. Linked accounts land on /v0/accounts. |
| Buy and sell | Shipped | Hosted ramp sessions for fiat to crypto and crypto to fiat against a Sumvin user. Launch chains: Sei (1329) and Base (8453). |
| Off-ramp | Shipped | Settle a user’s crypto to a linked fiat account. |
How it composes
- One identity envelope — the user verifies once with Sumvin. Every Meld flow inherits that state, so the widget does not re-collect KYC.
- One account surface — bank accounts linked through Meld appear on
/v0/accountsalongside any other linked accounts. You read balance, status, and transactions from the same endpoints regardless of provider. - One ramp endpoint family — buy, sell, and off-ramp all run through
/v0/ramp/quotesand/v0/ramp/sessions. You always sendfrom_asset,to_asset, andchain_id; direction is inferred from which side is fiat. See the on-ramp quickstart. - Asynchronous settlement — bank linking and ramp settlement are asynchronous. Poll
/v0/accountsor/v0/ramp/transactionsfor the terminal state.
Where to start
| Goal | Start here |
|---|---|
| Ship a buy flow end-to-end | On-ramp quickstart |
| Understand KYC reuse | KYC passthrough |
| Link a bank account | Bank linking |
| Ship sell or off-ramp | Buy and sell, Off-ramp |
| Look up valid currency, country, or payment-method values | Supported values |
| Look up an error code | Reference |
Related
- Ramp sessions — the conceptual model behind sessions and settlement
- KYC and attestation — how the KYC outcome gets reused downstream