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

# Feature coverage

> Every Buckspay feature mapped to its native Stellar mechanism, SDK surface, runnable example, and guide page.

Every Buckspay feature is an extension of an existing primitive that maps to a **native Stellar
mechanism** - "adding an auth method is an adapter, not a rewrite." This table is the index from
feature -> mechanism -> SDK surface -> runnable example -> guide.

| Feature                | Native Stellar mechanism                                            | SDK surface                                                      | Example                   | Guide                                            |
| ---------------------- | ------------------------------------------------------------------- | ---------------------------------------------------------------- | ------------------------- | ------------------------------------------------ |
| Gasless (sponsored)    | sponsor fee-bump (CAP-15) + sponsored reserves (CAP-33)             | `gas: { mode: "sponsored" }`                                     | `03-gasless-sponsored.ts` | [Gasless modes](/features/gasless-modes)         |
| Passkey smart account  | secp256r1 in `__check_auth` (CAP-51)                                | `@buckspay/accounts/oz-contract` + `passkey`                     | `02b-passkey-account.ts`  | [Account models](/concepts/account-models)       |
| Gas in stablecoin      | token-forwarding contract via relayer (FeeForwarder)                | `gas: { mode: "token", token }`                                  | `09-gas-in-token.ts`      | [Gas in token](/features/gas-in-token)           |
| Atomic batch           | multi-op tx (classic) / Multicall contract (Soroban)                | `sendCalls([...])` / `batch()`                                   | `10-batch.ts`             | [Atomic batch](/features/atomic-batch)           |
| Sessions               | policy signers in `__check_auth` (spend limit + allowlist on-chain) | `grantSession` / `revokeSession`                                 | `11-sessions.ts`          | [Sessions overview](/features/sessions/overview) |
| Parallel (transparent) | channel-account pool + non-sequential nonces (Protocol 23)          | none (facilitator throughput)                                    | -                         | [Atomic batch](/features/atomic-batch)           |
| Social login           | external provider -> ed25519 key -> smart-account signer            | `socialSigner({ provider: "web3auth" })`                         | `12-social-login.ts`      | [Social login](/signers/social-login)            |
| Email/SMS login        | external provider -> derived ed25519 key                            | `emailSigner({ proxyUrl })`                                      | `16-email-login.ts`       | [Social login](/signers/social-login)            |
| Mobile (React Native)  | native passkey (WebAuthn) + secure storage                          | `@buckspay/react-native` `nativePasskey`                         | `13-react-native.tsx`     | [React Native](/platforms/react-native)          |
| Server bindings (BFF)  | server-side relay + signer proxy                                    | `@buckspay/nextjs` `createRelayRoute` / `createSignerProxyRoute` | `15-nextjs-bff.ts`        | [Next.js BFF](/platforms/nextjs-bff)             |
| Swaps (optional)       | native DEX / Soroswap (reuses the facilitator `/swap/*` rail)       | `quoteSwap` / `swap`                                             | `14-swap.ts`              | [Swaps](/features/swaps)                         |

> **Swaps is optional** - the first surface deferred if the cycle tightens. The core (connect,
> gasless pay, gas-in-token, batch, sessions, social/email login, React Native) does not depend on
> it.

## Swaps - cut decision

**The EVM/Stellar seam.** The facilitator's existing `/swap/*` rail is the EVM Calibur (EIP-7702)
path: `/swap/submit` consumes an EIP-712 `batchSignature` from the payer's **EVM wallet**, not the
SDK's Soroban `BuckspaySigner`. `quoteSwap` is signer-agnostic and ships end-to-end; the `swap`
**submit** leg needs the EVM wallet path (the app BFF -> `/swap/submit`).

> **Decided: KEEP - 2026-06-30**

**As KEPT (current state):**

* `BuckspayClient.quoteSwap` ships end-to-end (delegates to `/swap/quote`, maps to `SwapQuote`).
* `BuckspayClient.swap` enforces the `minOut` floor before submit and fails closed (`SWAP_FAILED`)
  until the EVM wallet submit path (app BFF -> `/swap/submit`) is wired; the full submit leg / a
  native Stellar (Soroswap) rail is the future swap work.
* `buckspayFacilitator({ swapChain })` exposes `quoteSwap`/`swap`; without `swapChain` both are
  omitted. `docs/examples/14-swap.ts` and the gated `swap.e2e.test.ts` cover the quote path.

**If later cut:** revert this surface - the `Receipt.chain` widening, `Relayer.quoteSwap?`/`swap?`,
the `BuckspayClient.quoteSwap`/`swap` methods, the `swapChain` option, `docs/examples/14-swap.ts`,
the gated `swap.e2e.test.ts`, and this section's KEEP detail - and move swaps to a native DEX /
Soroswap rail on the Stellar side (removing the EVM seam).