> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sumvin.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Ramps & banking

> What Atomic Money ramps cover, which slices are available today, and where to start.

Atomic Money ramps are how a Sumvin user moves between fiat and crypto, and how they link a bank account, without you handling KYC re-collection, card rails, or bank connectivity.

<Snippet file="product-term-disambiguation.mdx" />

## 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. The ramp surface consolidates those into one place. 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. Ramps are powered by our ramp partner, Meld.

## What's available today

| Slice                                              | Status          | What it covers                                                                                                                   |
| -------------------------------------------------- | --------------- | -------------------------------------------------------------------------------------------------------------------------------- |
| [KYC passthrough](/products/ramps/kyc-passthrough) | live            | Your KYC-verified user does not re-verify inside the ramp widget.                                                                |
| [Bank linking](/products/ramps/bank-linking)       | private preview | Link a user's bank account through a hosted institution-connect flow. Linked accounts land on `/v0/accounts`.                    |
| [Buy and sell](/products/ramps/buy-sell)           | live            | Hosted ramp sessions for fiat to crypto and crypto to fiat against a Sumvin user. Launch chains: Sei (`1329`) and Base (`8453`). |
| [Off-ramp](/products/ramps/off-ramp)               | private preview | Settle a user's crypto to a linked fiat account.                                                                                 |

## How it composes

* **One identity envelope** — the user verifies once with Sumvin. Every ramp flow inherits that state, so the widget does not re-collect KYC.
* **One account surface** — bank accounts linked through the ramp surface appear on `/v0/accounts` alongside 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/quotes` and `/v0/ramp/sessions`. You always send `from_asset`, `to_asset`, and `chain_id`; direction is inferred from which side is fiat. See the [on-ramp quickstart](/guides/quickstarts/onramp-meld).
* **Asynchronous settlement** — bank linking and ramp settlement are asynchronous. Poll `/v0/accounts` or `/v0/ramp/transactions` for the terminal state.

## Where to start

| Goal                                                      | Start here                                                                     |
| --------------------------------------------------------- | ------------------------------------------------------------------------------ |
| Ship a buy flow end-to-end                                | [On-ramp quickstart](/guides/quickstarts/onramp-meld)                          |
| Understand KYC reuse                                      | [KYC passthrough](/products/ramps/kyc-passthrough)                             |
| Link a bank account                                       | [Bank linking](/products/ramps/bank-linking)                                   |
| Ship sell or off-ramp                                     | [Buy and sell](/products/ramps/buy-sell), [Off-ramp](/products/ramps/off-ramp) |
| Look up valid currency, country, or payment-method values | [Supported values](/products/ramps/supported-values)                           |
| Look up an error code                                     | [Reference](/products/ramps/reference)                                         |

## Related

* [Atomic Money](/products/atomic-money/overview) — the product these ramps belong to
* [Ramp sessions](/concepts/ramp-sessions) — the conceptual model behind sessions and settlement
* [KYC and attestation](/concepts/kyc-and-attestation) — how the KYC outcome gets reused downstream