Merge pull request #11 from Permissionless-Software-Foundation/dh-new-facilitators

feat(x402): Integrated payai facilitator

.env-example

@@ -34,16 +34,24 @@ export X402_PRICE_USDC=0.1
 # Use 'eip155:84532' for Base Sepolia (testnet)
 export x402_NETWORK=eip155:8453
 
-# Primary Facilitator
-# Options: 'cdp' (Coinbase) or 'dexter' (Dexter.cash - no API keys required)
-export PRIMARY_FACILITATOR=cdp
+# Primary Facilitator (used when ACTIVE_FACILITATORS is unset — single-facilitator mode)
+# Options: 'cdp' (Coinbase), 'dexter' (Dexter.cash), or 'payai' (PayAI)
+export PRIMARY_FACILITATOR=dexter
 
-# Facilitator URLs
-# For Coinbase CDP (recommended): https://api.cdp.coinbase.com/platform/v2/x402
-# For Dexter (no API keys):https://x402.dexter.cash
-# URL are not used when PRIMARY_FACILITATOR is set
+# Multi-facilitator (x402 v2): comma-separated *additional* facilitators; PRIMARY_FACILITATOR is always first (precedence).
+# x402_FACILITATOR_URL applies only in single-facilitator mode.
+# export ACTIVE_FACILITATORS=dexter,payai
+
+# Bazaar discovery extension on 402 payment requirements (default on). Set false to omit.
+# export X402_BAZAAR_ENABLED=true
+
+# Facilitator URL override (optional). If set, this URL is used regardless of PRIMARY_FACILITATOR.
+# Otherwise the URL is chosen from PRIMARY_FACILITATOR (built-in defaults per provider).
 # export x402_FACILITATOR_URL=https://api.cdp.coinbase.com/platform/v2/x402
 
+# PayAI only: optional custom facilitator host (default https://facilitator.payai.network)
+# export PAYAI_FACILITATOR_URL=https://facilitator.payai.network
+
 # CDP API Credentials (required when using CDP facilitator)
 # Get these from https://cdp.coinbase.com - API Keys section
 # Not required for Dexter facilitator

README.md

@@ -14,6 +14,8 @@ The API surface remains focused on BCH infrastructure (BCH full node, Fulcrum, a
 - Pricing is configured in `X402_PRICE_USDC` (USDC amount), not BCH satoshis.
 - x402 network is configured using CAIP-2 format (for example `eip155:8453` for Base mainnet and `eip155:84532` for Base Sepolia).
 - Facilitator auth headers are generated using Coinbase CDP JWT auth (`FACILITATOR_KEY_ID` and `FACILITATOR_SECRET_KEY`) when using CDP endpoints.
+- Optional facilitators: **Dexter** (`PRIMARY_FACILITATOR=dexter`) and **PayAI** (`PRIMARY_FACILITATOR=payai`, default URL `https://facilitator.payai.network`, no API keys).
+- **Bazaar** discovery metadata on payment requirements via `@x402/extensions/bazaar`, and optional **multi-facilitator** mode (`ACTIVE_FACILITATORS=cdp,dexter,payai`) so clients can verify/settle through CDP, Dexter, or PayAI (`@x402/core` picks a matching facilitator).
 
 ## Architecture
 
@@ -85,7 +87,11 @@ All configuration is loaded from environment variables (typically from `.env`).
 - `SERVER_BASE_ADDRESS` (EVM address receiving x402 settlements)
 - `X402_PRICE_USDC` (USDC charged per request)
 - `x402_NETWORK` (CAIP-2 chain ID; e.g. `eip155:8453` or `eip155:84532`)
-- `x402_FACILITATOR_URL` (default: `https://api.cdp.coinbase.com/platform/v2/x402`)
+- `PRIMARY_FACILITATOR` (default: `cdp`) — one of `cdp`, `dexter`, or `payai`. Used for **single-facilitator** mode when `ACTIVE_FACILITATORS` is unset; selects the default facilitator base URL unless `x402_FACILITATOR_URL` is set.
+- `ACTIVE_FACILITATORS` — optional comma-separated list (e.g. `dexter,payai`). When set with multi-facilitator mode, the server registers **multiple** `HTTPFacilitatorClient` instances. **`PRIMARY_FACILITATOR` is always first** in that list (x402 gives earlier facilitators precedence); remaining names follow in the order listed, deduped. Each facilitator uses its default base URL (`x402_FACILITATOR_URL` applies only in **single-facilitator** mode).
+- `X402_BAZAAR_ENABLED` (default: `true`) — attach Bazaar **discovery** extension to protected route payment requirements (for facilitator catalogs). Set `false` to disable.
+- `x402_FACILITATOR_URL` — optional override for the facilitator HTTP base URL (must expose `/verify`, `/settle`, and `/supported` like the x402 reference facilitator). When unset, the URL is derived from `PRIMARY_FACILITATOR`. **Ignored per-facilitator when `ACTIVE_FACILITATORS` lists more than one entry** (each entry uses its provider URL).
+- `PAYAI_FACILITATOR_URL` — optional; when `PRIMARY_FACILITATOR=payai` and `x402_FACILITATOR_URL` is unset, defaults to `https://facilitator.payai.network`.
 - `FACILITATOR_KEY_ID` (required for CDP facilitator auth)
 - `FACILITATOR_SECRET_KEY` (required for CDP facilitator auth)
 
@@ -123,17 +129,30 @@ Authorization: Bearer my-secret-token
 
 ### 3) x402 Payments on Base (USDC)
 
+**Coinbase CDP facilitator**
+
 ```bash
 X402_ENABLED=true
 USE_BASIC_AUTH=false
 SERVER_BASE_ADDRESS=0xYourBaseAddress
 X402_PRICE_USDC=0.1
 x402_NETWORK=eip155:8453
-x402_FACILITATOR_URL=https://api.cdp.coinbase.com/platform/v2/x402
+PRIMARY_FACILITATOR=cdp
 FACILITATOR_KEY_ID=your_key_id
 FACILITATOR_SECRET_KEY=your_secret
 ```
 
+**PayAI facilitator** (no CDP keys; default URL `https://facilitator.payai.network`)
+
+```bash
+X402_ENABLED=true
+USE_BASIC_AUTH=false
+SERVER_BASE_ADDRESS=0xYourBaseAddress
+X402_PRICE_USDC=0.1
+x402_NETWORK=eip155:8453
+PRIMARY_FACILITATOR=payai
+```
+
 Protected endpoints return `402 Payment Required` when no valid payment is attached. x402-capable clients can pay and retry automatically.
 
 ### 4) x402 + Bearer Bypass

bin/server.js

@@ -18,7 +18,7 @@ import { dirname, join } from 'path'
 import config from '../src/config/index.js'
 import Controllers from '../src/controllers/index.js'
 import wlogger from '../src/adapters/wlogger.js'
-import { buildX402Routes, getX402Settings, getBasicAuthSettings, createAuthHeader, getFacilitatorConfig } from '../src/config/x402.js'
+import { buildX402Routes, getX402Settings, getBasicAuthSettings, createAuthHeader, getFacilitatorConnectionOptions } from '../src/config/x402.js'
 import { basicAuthMiddleware } from '../src/middleware/basic-auth.js'
 import DiscoveryRouter from '../src/controllers/discovery/router.js'
 
@@ -126,19 +126,17 @@ class Server {
         // X402_ENABLED=true AND USE_BASIC_AUTH=true: Apply x402 conditionally
         const routes = buildX402Routes(this.config.apiPrefix)
 
-        const primaryFacilitator = x402Settings.primaryFacilitator || 'cdp'
-        const facilitatorConfig = getFacilitatorConfig(primaryFacilitator)
-        const facilitatorOptions = {
-          url: facilitatorConfig.url,
-          createAuthHeaders: facilitatorConfig.requiresAuth ? createAuthHeader : null
-        }
+        const connectionOpts = getFacilitatorConnectionOptions()
+        const facilitatorClients = connectionOpts.map(o => new HTTPFacilitatorClient({
+          url: o.url,
+          createAuthHeaders: o.requiresAuth ? createAuthHeader : null
+        }))
 
-        wlogger.info(`x402 v2 middleware enabled with basic auth bypass; enforcing ${x402Settings.priceUSDC} USDC per request (unless basic auth provided) [facilitator: ${facilitatorConfig.name}]`)
+        wlogger.info(`x402 v2 middleware enabled with basic auth bypass; enforcing ${x402Settings.priceUSDC} USDC per request (unless basic auth provided) [facilitators: ${connectionOpts.map(o => o.name).join(', ')}]`)
 
-        const facilitatorClient = new HTTPFacilitatorClient(facilitatorOptions)
         // x402 v2 exports use lowercase class names (x402ResourceServer).
         // eslint-disable-next-line new-cap
-        const resourceServer = new x402ResourceServer(facilitatorClient)
+        const resourceServer = new x402ResourceServer(facilitatorClients)
         registerExactEvmScheme(resourceServer, {})
         const x402Mw = x402PaymentMiddleware(routes, resourceServer)
 
@@ -152,22 +150,19 @@ class Server {
 
         app.use(conditionalX402Middleware)
 
-        // Display facilitator running url
-        console.log(`Facilitator running on: ${facilitatorOptions.url}`)
+        console.log(`Facilitator(s): ${connectionOpts.map(o => `${o.name} → ${o.url}`).join(' | ')}`)
       } else if (x402Settings.enabled && !basicAuthSettings.enabled) {
         const routes = buildX402Routes(this.config.apiPrefix)
-        const primaryFacilitator = x402Settings.primaryFacilitator || 'cdp'
-        const facilitatorConfig = getFacilitatorConfig(primaryFacilitator)
-        const facilitatorOptions = {
-          url: facilitatorConfig.url,
-          createAuthHeaders: facilitatorConfig.requiresAuth ? createAuthHeader : null
-        }
+        const connectionOpts = getFacilitatorConnectionOptions()
+        const facilitatorClients = connectionOpts.map(o => new HTTPFacilitatorClient({
+          url: o.url,
+          createAuthHeaders: o.requiresAuth ? createAuthHeader : null
+        }))
 
-        wlogger.info(`x402 v2 middleware enabled (basic auth disabled); enforcing ${x402Settings.priceUSDC} USDC per request [facilitator: ${facilitatorConfig.name}]`)
+        wlogger.info(`x402 v2 middleware enabled (basic auth disabled); enforcing ${x402Settings.priceUSDC} USDC per request [facilitators: ${connectionOpts.map(o => o.name).join(', ')}]`)
 
-        const facilitatorClient = new HTTPFacilitatorClient(facilitatorOptions)
         // eslint-disable-next-line new-cap
-        const resourceServer = new x402ResourceServer(facilitatorClient)
+        const resourceServer = new x402ResourceServer(facilitatorClients)
         registerExactEvmScheme(resourceServer, {})
         app.use(x402PaymentMiddleware(routes, resourceServer))
       } else if (basicAuthSettings.enabled && !x402Settings.enabled) {

package-lock.json

@@ -15,6 +15,7 @@
         "@x402/core": "2.6.0",
         "@x402/evm": "2.6.0",
         "@x402/express": "2.6.0",
+        "@x402/extensions": "2.6.0",
         "axios": "1.7.7",
         "cors": "2.8.5",
         "dotenv": "16.3.1",

package.json

@@ -23,6 +23,7 @@
     "@x402/core": "2.6.0",
     "@x402/evm": "2.6.0",
     "@x402/express": "2.6.0",
+    "@x402/extensions": "2.6.0",
     "axios": "1.7.7",
     "cors": "2.8.5",
     "dotenv": "16.3.1",

production/docker/.env-example

@@ -30,9 +30,23 @@ export X402_ENABLED=true
 export SERVER_BASE_ADDRESS=0xd32585CE60815654C50CAf350e18de8096061e63
 export X402_PRICE_USDC=0.1
 export x402_NETWORK=base
+export ACTIVE_FACILITATORS=dexter,payai
+export X402_BAZAAR_ENABLED=true
+export PRIMARY_FACILITATOR=cdp
 
-# Coinbase CDP Facilitator (for Bazaar registration)
-export x402_FACILITATOR_URL=https://api.cdp.coinbase.com/platform/v2/x402
+# Facilitator: cdp (default) | dexter | payai. Default base URL follows PRIMARY_FACILITATOR unless x402_FACILITATOR_URL is set.
+# export PRIMARY_FACILITATOR=payai
+# Multi-facilitator (CDP + Dexter + PayAI): unset x402_FACILITATOR_URL or use single-facilitator mode only.
+# export ACTIVE_FACILITATORS=cdp,dexter,payai
+# Bazaar discovery on 402 responses (default on)
+# export X402_BAZAAR_ENABLED=true
+# Optional PayAI host override (default https://facilitator.payai.network)
+# export PAYAI_FACILITATOR_URL=https://facilitator.payai.network
+
+# Optional: force a specific facilitator base URL (overrides PRIMARY_FACILITATOR URL resolution)
+# export x402_FACILITATOR_URL=https://api.cdp.coinbase.com/platform/v2/x402
+
+# CDP JWT credentials (required only when using Coinbase CDP)
 export FACILITATOR_KEY_ID=your_key_id_here
 export FACILITATOR_SECRET_KEY=your_secret_key_here
 

src/config/env/common.js

@@ -48,16 +48,36 @@ const x402NetworkRaw =
   'eip155:8453'
 const x402Network = toV2Caip2Network(x402NetworkRaw)
 
+const primaryFacilitatorRaw = (process.env.PRIMARY_FACILITATOR || 'cdp').trim().toLowerCase()
+const x402PrimaryKeys = new Set(['cdp', 'dexter', 'payai'])
+const primaryFacilitator = x402PrimaryKeys.has(primaryFacilitatorRaw)
+  ? primaryFacilitatorRaw
+  : 'cdp'
+
+function resolveX402FacilitatorUrl () {
+  const explicit = (process.env.x402_FACILITATOR_URL || '').trim()
+  if (explicit) return explicit.replace(/\/$/, '')
+
+  if (primaryFacilitator === 'dexter') return 'https://x402.dexter.cash'
+  if (primaryFacilitator === 'payai') {
+    return (process.env.PAYAI_FACILITATOR_URL || 'https://facilitator.payai.network')
+      .trim()
+      .replace(/\/$/, '')
+  }
+  return 'https://api.cdp.coinbase.com/platform/v2/x402'
+}
+
 const x402Defaults = {
   enabled: normalizeBoolean(process.env.X402_ENABLED, true),
-  // CDP Facilitator: https://api.cdp.coinbase.com/platform/v2/x402
-  // Custom/Local Facilitator: http://localhost:4022
-  facilitatorUrl: process.env.x402_FACILITATOR_URL || 'https://api.cdp.coinbase.com/platform/v2/x402',
+  // Bazaar discovery extension on payment requirements (for facilitator catalogs). @x402/express loads @x402/extensions/bazaar when enabled.
+  bazaarEnabled: normalizeBoolean(process.env.X402_BAZAAR_ENABLED, true),
+  // Resolved from PRIMARY_FACILITATOR unless x402_FACILITATOR_URL is set (see resolveX402FacilitatorUrl).
+  facilitatorUrl: resolveX402FacilitatorUrl(),
   // EVM 0x… address for USDC settlement; required for x402 exact scheme (no legacy BCH default).
   serverAddress: (process.env.SERVER_BASE_ADDRESS || '').trim(),
   facilitatorKeyId: process.env.FACILITATOR_KEY_ID || '',
   facilitatorSecretKey: process.env.FACILITATOR_SECRET_KEY || '',
-  primaryFacilitator: process.env.PRIMARY_FACILITATOR || 'cdp',
+  primaryFacilitator,
   network: x402Network,
   priceUSDC,
   // Optional: USDC token contract (0x…). If unset, Base / Base Sepolia use built-in USDC addresses.

src/config/x402.js

@@ -1,5 +1,6 @@
 import config from './index.js'
 import { generateJwt } from '@coinbase/cdp-sdk/auth'
+import { declareDiscoveryExtension } from '@x402/extensions/bazaar'
 
 const DEFAULT_DESCRIPTION = 'Access to protected psf-bch-api resources'
 const DEFAULT_TIMEOUT_SECONDS = 120
@@ -20,6 +21,12 @@ const FACILITATORS = {
     url: 'https://x402.dexter.cash',
     requiresAuth: false,
     authType: 'none'
+  },
+  payai: {
+    name: 'PayAI',
+    url: 'https://facilitator.payai.network',
+    requiresAuth: false,
+    authType: 'none'
   }
 }
 
@@ -54,26 +61,114 @@ export function buildX402Routes (apiPrefix = '/v6') {
   if (!payTo) throw new Error('SERVER_BASE_ADDRESS is required for x402 v2 payTo.')
   assertEvmPayTo(payTo)
 
-  return {
-    [routeKey]: {
-      accepts: [
-        {
-          scheme: 'exact',
-          payTo,
-          price: config.x402.priceUSDC,
-          network,
-          maxTimeoutSeconds: DEFAULT_TIMEOUT_SECONDS
-        }
-      ],
-      description: `${DEFAULT_DESCRIPTION} (${config.x402.priceUSDC} USDC)`,
-      mimeType: 'application/json'
-    }
+  const entry = {
+    accepts: [
+      {
+        scheme: 'exact',
+        payTo,
+        price: config.x402.priceUSDC,
+        network,
+        maxTimeoutSeconds: DEFAULT_TIMEOUT_SECONDS
+      }
+    ],
+    description: `${DEFAULT_DESCRIPTION} (${config.x402.priceUSDC} USDC)`,
+    mimeType: 'application/json'
   }
+
+  if (config.x402.bazaarEnabled) {
+    entry.extensions = declareDiscoveryExtension({
+      output: {
+        example: {
+          service: 'psf-bch-api',
+          apiPrefix: prefixWithSlash,
+          description: 'Bitcoin Cash full node, Fulcrum, and SLP indexer REST proxy (x402 USDC on Base)'
+        }
+      }
+    })
+  }
+
+  return {
+    [routeKey]: entry
+  }
+}
+
+/**
+ * Default facilitator order when ACTIVE_FACILITATORS lists CDP, Dexter, and PayAI (Bazaar-friendly multi-facilitator).
+ */
+export const DEFAULT_MULTI_FACILITATORS = ['cdp', 'dexter', 'payai']
+
+/**
+ * Per-facilitator HTTP base URL (no trailing slash). Used when multiple facilitators are active.
+ * @param {string} key
+ */
+export function getFacilitatorHttpUrl (key) {
+  const k = String(key || 'cdp').trim().toLowerCase()
+  if (k === 'dexter') return 'https://x402.dexter.cash'
+  if (k === 'payai') {
+    return (process.env.PAYAI_FACILITATOR_URL || 'https://facilitator.payai.network')
+      .trim()
+      .replace(/\/$/, '')
+  }
+  return 'https://api.cdp.coinbase.com/platform/v2/x402'
+}
+
+/**
+ * Resolved primary facilitator key (env PRIMARY_FACILITATOR, then config, then cdp).
+ * @returns {string}
+ */
+export function resolvePrimaryFacilitatorKey () {
+  const primaryRaw = (
+    process.env.PRIMARY_FACILITATOR ||
+    config.x402?.primaryFacilitator ||
+    'cdp'
+  ).trim().toLowerCase()
+  return FACILITATORS[primaryRaw] ? primaryRaw : 'cdp'
+}
+
+/**
+ * Active facilitator keys: PRIMARY_FACILITATOR is always first (x402 core gives earlier
+ * facilitator clients precedence). Remaining keys follow ACTIVE_FACILITATORS order, deduped.
+ * @returns {string[]}
+ */
+export function getActiveFacilitatorKeys () {
+  const primary = resolvePrimaryFacilitatorKey()
+  const raw = (process.env.ACTIVE_FACILITATORS || '').trim()
+  if (!raw) {
+    return [primary]
+  }
+  const fromEnv = raw.split(',').map(s => s.trim().toLowerCase()).filter(k => FACILITATORS[k])
+  if (fromEnv.length === 0) {
+    return [primary]
+  }
+  const rest = fromEnv.filter(k => k !== primary)
+  return [primary, ...rest]
+}
+
+/**
+ * Options for constructing one {@link import('@x402/core/server').HTTPFacilitatorClient} per facilitator.
+ * When only one facilitator is active, `url` is `config.x402.facilitatorUrl` so `x402_FACILITATOR_URL` still applies.
+ * @returns {{ key: string, name: string, url: string, requiresAuth: boolean }[]}
+ */
+export function getFacilitatorConnectionOptions () {
+  const keys = getActiveFacilitatorKeys()
+  return keys.map(key => {
+    const cfg = getFacilitatorConfig(key)
+    const url =
+      keys.length === 1 ? config.x402.facilitatorUrl : getFacilitatorHttpUrl(key)
+    return {
+      key,
+      name: cfg.name,
+      url,
+      requiresAuth: Boolean(cfg.requiresAuth)
+    }
+  })
 }
 
 export function getX402Settings () {
   return {
     enabled: Boolean(config.x402?.enabled),
+    bazaarEnabled: Boolean(config.x402?.bazaarEnabled),
+    activeFacilitatorKeys: getActiveFacilitatorKeys(),
     facilitatorUrl: config.x402?.facilitatorUrl,
     facilitatorKeyId: config.x402?.facilitatorKeyId,
     facilitatorSecretKey: config.x402?.facilitatorSecretKey,
@@ -214,11 +309,12 @@ export async function createAuthHeader () {
 
 /**
  * Get facilitator configuration by name
- * @param {string} name - Facilitator name ('cdp' or 'dexter')
+ * @param {string} name - Facilitator name (`cdp`, `dexter`, or `payai`)
  * @returns {Object} Facilitator config
  */
 export function getFacilitatorConfig (name = 'cdp') {
-  return FACILITATORS[name] || FACILITATORS.cdp
+  const key = String(name || 'cdp').trim().toLowerCase()
+  return FACILITATORS[key] || FACILITATORS.cdp
 }
 
 /**
@@ -227,6 +323,7 @@ export function getFacilitatorConfig (name = 'cdp') {
  * @returns {boolean}
  */
 export function facilitatorRequiresAuth (name = 'cdp') {
-  const cfg = FACILITATORS[name]
+  const key = String(name || 'cdp').trim().toLowerCase()
+  const cfg = FACILITATORS[key]
   return cfg ? cfg.requiresAuth : false
 }

test/unit/config/x402-facilitators-unit.js

@@ -0,0 +1,30 @@
+/*
+  Unit tests for x402 facilitator registry (PayAI, Dexter, CDP).
+*/
+
+import { assert } from 'chai'
+
+import {
+  getFacilitatorConfig,
+  facilitatorRequiresAuth
+} from '../../../src/config/x402.js'
+
+describe('#x402 facilitators', () => {
+  it('should register PayAI without auth', () => {
+    assert.equal(facilitatorRequiresAuth('payai'), false)
+    const cfg = getFacilitatorConfig('payai')
+    assert.equal(cfg.name, 'PayAI')
+    assert.equal(cfg.url, 'https://facilitator.payai.network')
+    assert.equal(cfg.requiresAuth, false)
+  })
+
+  it('should normalize facilitator key case', () => {
+    const cfg = getFacilitatorConfig('PAYAI')
+    assert.equal(cfg.name, 'PayAI')
+  })
+
+  it('should require auth for CDP only', () => {
+    assert.equal(facilitatorRequiresAuth('cdp'), true)
+    assert.equal(facilitatorRequiresAuth('dexter'), false)
+  })
+})

test/unit/config/x402-multifac-bazaar-unit.js

@@ -0,0 +1,51 @@
+/*
+  Multi-facilitator and Bazaar route config (env-dependent helpers).
+*/
+
+import { assert } from 'chai'
+
+import {
+  getActiveFacilitatorKeys,
+  getFacilitatorHttpUrl
+} from '../../../src/config/x402.js'
+
+describe('#x402 multi-facilitator + bazaar helpers', () => {
+  const saved = {}
+
+  beforeEach(() => {
+    saved.ACTIVE_FACILITATORS = process.env.ACTIVE_FACILITATORS
+    saved.PRIMARY_FACILITATOR = process.env.PRIMARY_FACILITATOR
+    delete process.env.ACTIVE_FACILITATORS
+    process.env.PRIMARY_FACILITATOR = 'cdp'
+  })
+
+  afterEach(() => {
+    if (saved.ACTIVE_FACILITATORS === undefined) delete process.env.ACTIVE_FACILITATORS
+    else process.env.ACTIVE_FACILITATORS = saved.ACTIVE_FACILITATORS
+    if (saved.PRIMARY_FACILITATOR === undefined) delete process.env.PRIMARY_FACILITATOR
+    else process.env.PRIMARY_FACILITATOR = saved.PRIMARY_FACILITATOR
+  })
+
+  it('getActiveFacilitatorKeys puts PRIMARY_FACILITATOR first, then ACTIVE_FACILITATORS', () => {
+    process.env.PRIMARY_FACILITATOR = 'cdp'
+    process.env.ACTIVE_FACILITATORS = 'payai,cdp,dexter'
+    assert.deepEqual(getActiveFacilitatorKeys(), ['cdp', 'payai', 'dexter'])
+  })
+
+  it('getActiveFacilitatorKeys prepends primary when not listed in ACTIVE_FACILITATORS', () => {
+    process.env.PRIMARY_FACILITATOR = 'cdp'
+    process.env.ACTIVE_FACILITATORS = 'dexter,payai'
+    assert.deepEqual(getActiveFacilitatorKeys(), ['cdp', 'dexter', 'payai'])
+  })
+
+  it('getActiveFacilitatorKeys falls back to PRIMARY_FACILITATOR', () => {
+    process.env.PRIMARY_FACILITATOR = 'dexter'
+    assert.deepEqual(getActiveFacilitatorKeys(), ['dexter'])
+  })
+
+  it('getFacilitatorHttpUrl returns known bases', () => {
+    assert.include(getFacilitatorHttpUrl('cdp'), 'cdp.coinbase.com')
+    assert.equal(getFacilitatorHttpUrl('dexter'), 'https://x402.dexter.cash')
+    assert.equal(getFacilitatorHttpUrl('payai'), 'https://facilitator.payai.network')
+  })
+})