docs: add Stellar payment method

src/components/cards.tsx

@@ -242,6 +242,39 @@ export function LightningSessionCard() {
   );
 }
 
+export function StellarMethodCard() {
+  return (
+    <Card
+      description="Smart contract payments on Stellar"
+      icon="simple-icons:stellar"
+      title="Stellar"
+      to="/payment-methods/stellar"
+    />
+  );
+}
+
+export function StellarChargeCard() {
+  return (
+    <Card
+      description="One-time SAC token transfers settled on-chain"
+      icon="simple-icons:stellar"
+      title="Stellar charge"
+      to="/payment-methods/stellar/charge"
+    />
+  );
+}
+
+export function StellarChannelCard() {
+  return (
+    <Card
+      description="Pay-as-you-go payments over one-way payment channels"
+      icon="simple-icons:stellar"
+      title="Stellar channel"
+      to="/payment-methods/stellar/session"
+    />
+  );
+}
+
 export function SolanaMethodCard() {
   return (
     <Card

src/pages.gen.ts

@@ -88,7 +88,6 @@ type Page =
 | { path: '/quickstart/server'; render: 'static' }
 | { path: '/protocol/challenges'; render: 'static' }
 | { path: '/protocol/credentials'; render: 'static' }
-| { path: '/protocol/discovery'; render: 'static' }
 | { path: '/protocol/http-402'; render: 'static' }
 | { path: '/protocol'; render: 'static' }
 | { path: '/protocol/receipts'; render: 'static' }
@@ -102,6 +101,9 @@ type Page =
 | { path: '/payment-methods/tempo/session'; render: 'static' }
 | { path: '/payment-methods/stripe/charge'; render: 'static' }
 | { path: '/payment-methods/stripe'; render: 'static' }
+| { path: '/payment-methods/stellar/charge'; render: 'static' }
+| { path: '/payment-methods/stellar'; render: 'static' }
+| { path: '/payment-methods/stellar/session'; render: 'static' }
 | { path: '/payment-methods/solana/charge'; render: 'static' }
 | { path: '/payment-methods/solana'; render: 'static' }
 | { path: '/payment-methods/lightning/charge'; render: 'static' }
@@ -114,7 +116,12 @@ type Page =
 | { path: '/guides/multiple-payment-methods'; render: 'static' }
 | { path: '/guides/one-time-payments'; render: 'static' }
 | { path: '/guides/pay-as-you-go'; render: 'static' }
+| { path: '/guides/proxy-existing-service'; render: 'static' }
+| { path: '/guides/split-payments'; render: 'static' }
 | { path: '/guides/streamed-payments'; render: 'static' }
+| { path: '/advanced/discovery'; render: 'static' }
+| { path: '/advanced/identity'; render: 'static' }
+| { path: '/advanced/refunds'; render: 'static' }
 | { path: '/_api/api/og'; render: 'static' };
 
 // prettier-ignore

src/pages/payment-methods/index.mdx

@@ -3,7 +3,7 @@ imageDescription: "Choose a payment method for your service"
 ---
 
 import { Cards, Tab, Tabs } from 'vocs'
-import { TempoMethodCard, CardMethodCard, LightningMethodCard, SolanaMethodCard, StripeMethodCard, CustomMethodCard } from '../../components/cards'
+import { TempoMethodCard, CardMethodCard, LightningMethodCard, StellarMethodCard, SolanaMethodCard, StripeMethodCard, CustomMethodCard } from '../../components/cards'
 
 # Payment methods [Available methods and how to choose one]
 
@@ -42,6 +42,12 @@ WWW-Authenticate: Payment method="lightning", intent="charge", ...
 ```http
 HTTP/1.1 402 Payment Required
 WWW-Authenticate: Payment method="solana", intent="charge", ...
+```
+  </Tab>
+  <Tab title="Stellar">
+```http
+HTTP/1.1 402 Payment Required
+WWW-Authenticate: Payment method="stellar", intent="charge", ...
 ```
   </Tab>
 </Tabs>
@@ -54,5 +60,6 @@ WWW-Authenticate: Payment method="solana", intent="charge", ...
   <CardMethodCard />
   <LightningMethodCard />
   <SolanaMethodCard />
+  <StellarMethodCard />
   <CustomMethodCard />
 </Cards>

src/pages/payment-methods/stellar/charge.mdx

@@ -0,0 +1,221 @@
+---
+imageDescription: "One-time stablecoin payments on Stellar"
+---
+
+import { Cards, Tab, Tabs } from 'vocs'
+import { MermaidDiagram } from '../../../components/MermaidDiagram'
+
+# Stellar charge [One-time SEP-41 token transfers]
+
+The Stellar implementation of the [charge](/intents/charge) intent.
+
+The client signs a SEP-41 `transfer` invocation, and the server verifies and broadcasts the transaction on-chain. Settlement completes in ~5 seconds with deterministic finality.
+
+Stellar charge supports two credential modes:
+
+- **Pull mode** (default): The client signs Stellar auth entries and sends the transaction XDR. The server broadcasts it. Two variants: sponsored (server holds an envelope signer and optionally wraps with a fee bump) or unsponsored (server broadcasts the transaction as-is, without modification).
+- **Push mode**: The client builds, signs, and broadcasts the transaction itself, then sends the transaction hash. The server polls for confirmation.
+
+This method is best for single API calls, content access, or one-off purchases.
+
+## How it works
+
+<MermaidDiagram chart={`sequenceDiagram
+    participant Client
+    participant Server
+    participant Stellar
+    Client->>Server: (1) GET /resource
+    Server-->>Client: 402 + Challenge (amount, currency, recipient)
+    Client->>Client: (2) Build SEP-41 transfer, sign auth entries
+    Client->>Server: (3) Retry with Credential (signed XDR)
+    Server->>Stellar: (4) Simulate + broadcast transaction
+    Stellar-->>Server: Transaction confirmed
+    Server-->>Client: 200 OK + Receipt
+`} />
+
+## Server
+
+Use `stellar.charge` to gate any endpoint behind a one-time SEP-41 token payment. The method handles Challenge generation, Credential verification, transaction broadcast, and Receipt creation.
+
+```ts
+import express from 'express'
+import { Mppx } from 'mppx/server'
+import { stellar } from '@stellar/mpp/charge/server'
+import { USDC_SAC_TESTNET } from '@stellar/mpp'
+
+const mppx = Mppx.create({
+  secretKey: process.env.MPP_SECRET_KEY,
+  methods: [
+    stellar.charge({
+      recipient: process.env.STELLAR_RECIPIENT,
+      currency: USDC_SAC_TESTNET,
+      network: 'stellar:testnet',
+    }),
+  ],
+})
+
+const app = express()
+
+app.get('/my-service', async (req, res) => {
+  const webReq = new Request(`http://localhost:3000${req.url}`, {
+    method: req.method,
+    headers: new Headers(req.headers as Record<string, string>),
+  })
+
+  const result = await mppx.charge({
+    amount: '0.01',
+    description: 'Premium API access',
+  })(webReq)
+
+  if (result.status === 402) {
+    const challenge = result.challenge
+    challenge.headers.forEach((value, key) => res.setHeader(key, value))
+    return res.status(402).send(await challenge.text())
+  }
+
+  const response = result.withReceipt(
+    Response.json({ message: 'Payment verified' }),
+  )
+  response.headers.forEach((value, key) => res.setHeader(key, value))
+  return res.status(response.status).send(await response.text())
+})
+
+app.listen(3000)
+```
+
+### With fee sponsorship
+
+When `feePayer` is configured, the server adds its own source account and optionally wraps the transaction in a fee bump before broadcasting. The client doesn't need XLM for gas – it signs only the Stellar auth entries.
+
+```ts
+import { Mppx } from 'mppx/server'
+import { stellar } from '@stellar/mpp/charge/server'
+import { USDC_SAC_TESTNET } from '@stellar/mpp'
+import { Keypair } from '@stellar/stellar-sdk'
+
+const mppx = Mppx.create({
+  secretKey: process.env.MPP_SECRET_KEY,
+  methods: [
+    stellar.charge({
+      recipient: process.env.STELLAR_RECIPIENT,
+      currency: USDC_SAC_TESTNET,
+      network: 'stellar:testnet',
+      feePayer: { // [!code hl]
+        envelopeSigner: Keypair.fromSecret(process.env.FEE_PAYER_SECRET), // [!code hl]
+        feeBumpSigner: Keypair.fromSecret(process.env.FEE_BUMP_SECRET), // optional // [!code hl]
+      }, // [!code hl]
+    }),
+  ],
+})
+```
+
+### Server configuration
+
+| Parameter | Type | Default | Description |
+|---|---|---|---|
+| `currency` | `string` | – | SEP-41 token contract address |
+| `decimals` | `number` | `7` | Token decimal precision |
+| `feePayer` | `object` | – | Fee sponsorship configuration |
+| `maxFeeBumpStroops` | `number` | `10,000,000` | Maximum fee bump amount in stroops |
+| `network` | `string` | – | `'stellar:testnet'` or `'stellar:pubnet'` |
+| `pollDelayMs` | `number` | `1,000` | Delay between transaction poll attempts |
+| `pollMaxAttempts` | `number` | `30` | Maximum transaction poll attempts |
+| `pollTimeoutMs` | `number` | `30,000` | Total poll timeout |
+| `recipient` | `string` | – | Stellar public key (`G...`) or contract (`C...`) |
+| `rpcUrl` | `string` | – | Stellar RPC endpoint |
+| `simulationTimeoutMs` | `number` | `10,000` | Simulation timeout |
+| `store` | `Store` | – | State store for replay protection |
+
+## Client
+
+Use `stellar.charge` with `Mppx.create` to automatically handle `402` responses. The client signs SEP-41 transfer auth entries and retries with the Credential.
+
+```ts
+import { Keypair } from '@stellar/stellar-sdk'
+import { Mppx } from 'mppx/client'
+import { stellar } from '@stellar/mpp/charge/client'
+
+Mppx.create({
+  methods: [
+    stellar.charge({
+      keypair: Keypair.fromSecret('S...'),
+      mode: 'pull',
+      onProgress(event) {
+        console.log(event.type) // challenge → signing → signed → paying → confirming → paid
+      },
+    }),
+  ],
+})
+
+const response = await fetch('http://localhost:3000/my-service')
+const data = await response.json()
+```
+
+### Push mode
+
+In push mode, the client broadcasts the transaction and sends the hash for server verification:
+
+```ts
+import { Keypair } from '@stellar/stellar-sdk'
+import { Mppx } from 'mppx/client'
+import { stellar } from '@stellar/mpp/charge/client'
+
+Mppx.create({
+  methods: [
+    stellar.charge({
+      keypair: Keypair.fromSecret('S...'),
+      mode: 'push', // [!code hl]
+    }),
+  ],
+})
+```
+
+### Without polyfill
+
+If you don't want to patch `globalThis.fetch`, use `mppx.fetch` directly:
+
+```ts
+import { Keypair } from '@stellar/stellar-sdk'
+import { Mppx } from 'mppx/client'
+import { stellar } from '@stellar/mpp/charge/client'
+
+const mppx = Mppx.create({
+  methods: [
+    stellar.charge({
+      keypair: Keypair.fromSecret('S...'),
+    }),
+  ],
+  polyfill: false,
+})
+
+const response = await mppx.fetch('http://localhost:3000/my-service')
+```
+
+### Client configuration
+
+| Parameter | Type | Default | Description |
+|---|---|---|---|
+| `decimals` | `number` | `7` | Token decimal precision |
+| `keypair` | `Keypair` | – | Stellar keypair for signing |
+| `mode` | `'pull' \| 'push'` | `'pull'` | Credential mode |
+| `onProgress` | `function` | – | Lifecycle event callback |
+| `pollDelayMs` | `number` | `1,000` | Delay between poll attempts (push mode) |
+| `pollMaxAttempts` | `number` | `30` | Maximum poll attempts (push mode) |
+| `pollTimeoutMs` | `number` | `30,000` | Total poll timeout (push mode) |
+| `rpcUrl` | `string` | – | Stellar RPC endpoint |
+| `secretKey` | `string` | – | Stellar secret key (alternative to `keypair`) |
+| `simulationTimeoutMs` | `number` | `10,000` | Simulation timeout |
+| `timeout` | `number` | `180` | Transaction timeout in seconds |
+
+### Progress events
+
+The `onProgress` callback fires at each stage of the charge flow:
+
+| Event | Description |
+|---|---|
+| `challenge` | Challenge received from server |
+| `signing` | Building and signing SEP-41 transfer |
+| `signed` | Transaction signed |
+| `paying` | Sending Credential to server |
+| `confirming` | Waiting for on-chain confirmation (push mode) |
+| `paid` | Payment confirmed, Receipt received |