Summary
Turns Claude into a paying API consumer using USDC on Base L2. Exposes three tools: xenarch_check_gate to inspect if a URL requires payment, xenarch_pay to sign an EIP-3009 transfer and fetch gated content, and xenarch_get_history to review past transactions. The agent wallet only needs USDC, never ETH. Payments settle on-chain directly to the publisher with zero platform fees. Implements the x402 spec for HTTP 402 responses. Reach for this when you want Claude to autonomously pay for paywalled APIs or content without API keys, subscriptions, or manual approval flows. Works with any MCP client including Cursor, LangChain, and CrewAI.
Keep your Mac awake while Claude Code and 40+ AI agents run. Sleeps when they're idle.
One time payment $9 →
Integrate web data into your AI product. One API to scrape website & brand data.
Get API Key Now →
Agent, run crypto. Access onchain data & trade routes via 1inch.
Install now →
On Capafy, your Skill runs online 24/7 as an agent product, and you get paid every time someone uses it.
Start earning →
Tools
Public tool metadata for what this MCP can expose to an agent.
29 tools
xenarch_check_gateCheck if a URL or domain has an x402 payment gate. Returns gate status, accepted payment requirements (price, asset, network), and the seller wallet. Use this before paying to confirm pricing, when a URL returns HTTP 402 Payment Required, or when a user asks whether content is...1 params
Check if a URL or domain has an x402 payment gate. Returns gate status, accepted payment requirements (price, asset, network), and the seller wallet. Use this before paying to confirm pricing, when a URL returns HTTP 402 Payment Required, or when a user asks whether content is...
Parameters* required
urlstringThe URL or domain to check for an x402 payment gate. Accepts a full URL (https://example.com/article) or bare domain (example.com). Returns pricing in USD and payment requirements if gated.
xenarch_payPay an x402-gated URL with USDC on Base L2 and return the gated content. Signs an EIP-3009 transferWithAuthorization, settles on-chain, then re-fetches the resource with proof of payment. Returns the on-chain tx_hash, seller wallet, and the response body. Settles directly to t...1 params
Pay an x402-gated URL with USDC on Base L2 and return the gated content. Signs an EIP-3009 transferWithAuthorization, settles on-chain, then re-fetches the resource with proof of payment. Returns the on-chain tx_hash, seller wallet, and the response body. Settles directly to t...
Parameters* required
urlstringThe URL or domain to pay for. Must have an active x402 payment gate. Payment settles in USDC on Base L2, agent wallet to seller wallet direct. The agent wallet only ever holds USDC; no ETH or other gas coin needed.
xenarch_get_historyList past USDC micropayments made by this wallet through Xenarch. Returns transaction hashes, URLs, domains, amounts in USD, timestamps, total spend, and payment count. Optionally filter by domain. Use this to audit spending, check if you already paid for a resource, or track...2 params
List past USDC micropayments made by this wallet through Xenarch. Returns transaction hashes, URLs, domains, amounts in USD, timestamps, total spend, and payment count. Optionally filter by domain. Use this to audit spending, check if you already paid for a resource, or track...
Parameters* required
limitintegerMaximum number of payment records to return (1-100, default 10). Use higher values to see full spending history.default: 10
domainstringFilter payment history by domain (e.g. 'example.com'). Omit to return all payments across all domains.
xenarch_agent_loginSign in to the agent control plane using your browser wallet — no CLI needed. First call returns a link; open it, sign in with your wallet on the dashboard, and approve. Call this tool again to finish — the 7-day session is then used by every other xenarch_agent_* tool. Use th...
Sign in to the agent control plane using your browser wallet — no CLI needed. First call returns a link; open it, sign in with your wallet on the dashboard, and approve. Call this tool again to finish — the 7-day session is then used by every other xenarch_agent_* tool. Use th...
No parameter schema in public metadata yet.
xenarch_agent_statusShow the operator's agent profile (name, paused state) and spend summary for a period. Read-only. Needs a SIWE session from `xenarch agent login`.1 params
Show the operator's agent profile (name, paused state) and spend summary for a period. Read-only. Needs a SIWE session from `xenarch agent login`.
Parameters* required
periodstringSpend-summary window.one of
24h · 7d · 30d · alldefault: 24hxenarch_agent_get_capsRead the agent's spending caps (per-transaction, daily, monthly) and remaining headroom. Read-only.
Read the agent's spending caps (per-transaction, daily, monthly) and remaining headroom. Read-only.
No parameter schema in public metadata yet.
xenarch_agent_set_capsSet spending caps. Pass per_tx/daily/monthly in USD ('none' disables an axis); omit an axis to leave it unchanged. RAISING or REMOVING a cap requires confirm: true (returns needs_confirmation otherwise). Tightening is free.4 params
Set spending caps. Pass per_tx/daily/monthly in USD ('none' disables an axis); omit an axis to leave it unchanged. RAISING or REMOVING a cap requires confirm: true (returns needs_confirmation otherwise). Tightening is free.
Parameters* required
dailystringDaily cap in USD, or 'none' to disable. Omit to leave unchanged.
per_txstringPer-transaction cap in USD, or 'none' to disable. Omit to leave unchanged.
confirmbooleanRequired true to RAISE or REMOVE a cap (a loosening change).default: false
monthlystringMonthly cap in USD, or 'none' to disable. Omit to leave unchanged.
xenarch_agent_reset_day_capReset today's daily-spend counter back to the full daily cap (recovery from accidental mid-day exhaustion).
Reset today's daily-spend counter back to the full daily cap (recovery from accidental mid-day exhaustion).
No parameter schema in public metadata yet.
xenarch_agent_get_scopeRead the agent's scope: default posture (allow/deny) and the allow/deny rule list. Read-only.
Read the agent's scope: default posture (allow/deny) and the allow/deny rule list. Read-only.
No parameter schema in public metadata yet.
xenarch_agent_add_scope_ruleAdd an allow/deny scope rule. A 'deny' rule tightens (free); an 'allow' rule loosens and requires confirm: true.4 params
Add an allow/deny scope rule. A 'deny' rule tightens (free); an 'allow' rule loosens and requires confirm: true.
Parameters* required
modestring'deny' blocks (tightens); 'allow' permits (loosens — needs confirm).one of
allow · denylabelstringOptional human label for the rule.
confirmbooleanRequired true for an 'allow' rule (loosens scope).default: false
patternstringURL/domain glob the rule matches, e.g. 'api.example.com/*'.
xenarch_agent_remove_scope_ruleRemove a scope rule by id (full UUID or unambiguous prefix). Removing a DENY rule loosens scope and requires confirm: true.2 params
Remove a scope rule by id (full UUID or unambiguous prefix). Removing a DENY rule loosens scope and requires confirm: true.
Parameters* required
idstringScope rule id (full UUID or unambiguous prefix from get_scope).
confirmbooleanRequired true when removing a DENY rule (loosens scope).default: false
xenarch_agent_set_default_scopeSet the default scope posture for unmatched URLs. 'deny' tightens (free); 'allow' loosens and requires confirm: true.2 params
Set the default scope posture for unmatched URLs. 'deny' tightens (free); 'allow' loosens and requires confirm: true.
Parameters* required
modestringDefault posture for unmatched URLs. 'allow' loosens — needs confirm.one of
allow · denyconfirmbooleanRequired true to switch the default to 'allow'.default: false
xenarch_agent_pauseKill switch: pause the agent so all of its payments are blocked immediately. Tightening, so no confirm needed.
Kill switch: pause the agent so all of its payments are blocked immediately. Tightening, so no confirm needed.
No parameter schema in public metadata yet.
xenarch_agent_resumeLift the pause so the agent can spend again (subject to caps + scope). Requires confirm: true.1 params
Lift the pause so the agent can spend again (subject to caps + scope). Requires confirm: true.
Parameters* required
confirmbooleanRequired true: resuming re-enables the agent's spending.default: false
xenarch_agent_list_keysList the agent's xa_live_ API keys (id, label, last-used, revoked state). Never returns plaintext. Read-only.
List the agent's xa_live_ API keys (id, label, last-used, revoked state). Never returns plaintext. Read-only.
No parameter schema in public metadata yet.
xenarch_agent_create_keyIssue a new xa_live_ API key (plaintext returned once). Issues a live spending credential — requires confirm: true.2 params
Issue a new xa_live_ API key (plaintext returned once). Issues a live spending credential — requires confirm: true.
Parameters* required
labelstringOptional label for the new key.
confirmbooleanRequired true: issues a live xa_live_ spending credential.default: false
xenarch_agent_rotate_keyRotate an API key by id (full UUID or prefix) — invalidates the old secret, returns a new one once. Requires confirm: true.2 params
Rotate an API key by id (full UUID or prefix) — invalidates the old secret, returns a new one once. Requires confirm: true.
Parameters* required
key_idstringKey id (full UUID or unambiguous prefix).
confirmbooleanRequired true: invalidates the key's current secret.default: false
xenarch_agent_revoke_keyPermanently revoke an API key by id (full UUID or prefix). Requires confirm: true.2 params
Permanently revoke an API key by id (full UUID or prefix). Requires confirm: true.
Parameters* required
key_idstringKey id (full UUID or unambiguous prefix).
confirmbooleanRequired true: permanently disables the key.default: false
xenarch_agent_get_receiptsList the agent's payment receipts with filters (period, status, source, domain) and pagination. Read-only.6 params
List the agent's payment receipts with filters (period, status, source, domain) and pagination. Read-only.
Parameters* required
pageintegerPage number.default: 1
domainstringFilter by domain.
periodstringTime window.one of
24h · 7d · 30d · alldefault: allsourcestringFilter by source channel.one of
cli · mcp · sdk · customstatusstringFilter by status.one of
paid · pending · failedper_pageintegerRows per page (max 100).default: 25
xenarch_list_linksList the merchant's pay-links (newest first), with cursor pagination. Read-only. Needs a SIWE session from `xenarch agent login`.2 params
List the merchant's pay-links (newest first), with cursor pagination. Read-only. Needs a SIWE session from `xenarch agent login`.
Parameters* required
limitintegerPage size (default 25)
starting_afterstringCursor: last link_id of the previous page
xenarch_get_linkGet one pay-link's detail (status, params, stats) by id. Read-only.1 params
Get one pay-link's detail (status, params, stats) by id. Read-only.
Parameters* required
link_idstringThe pay-link id
xenarch_create_linkCreate a pay-link. VALIDATE-FIRST: call with mode:'validate' (default) to learn which fields are missing (each missing field includes a prompt to ask the user); once valid, call again with mode:'create' and confirm:true to sign + create. Signs with the agent's local key — the...6 params
Create a pay-link. VALIDATE-FIRST: call with mode:'validate' (default) to learn which fields are missing (each missing field includes a prompt to ask the user); once valid, call again with mode:'create' and confirm:true to sign + create. Signs with the agent's local key — the...
Parameters* required
kindstringPay-link kind: invoice, subscription, donation, ticket, bounty, paywall, api_metering, checkout, quick_charge
modestringvalidate (default) returns missing fields; create signs + createsone of
validate · createamountstringAmount in USDC, e.g. '0.99' (max 1.00), or 'open'
fieldsobjectAny additional create-body fields by name (see xenarch_create_link validate output / GET /v1/links/schema)
confirmbooleanRequired to actually sign + create in create mode
product_namestringProduct / line label
xenarch_revoke_linkRevoke a pay-link by id so it can no longer be paid. Requires confirm: true (returns needs_confirmation otherwise).2 params
Revoke a pay-link by id so it can no longer be paid. Requires confirm: true (returns needs_confirmation otherwise).
Parameters* required
confirmbooleanRequired to revoke
link_idstringThe pay-link id to revoke
xenarch_list_paymentsList payments RECEIVED across the merchant's pay-links (newest first), with cursor pagination. Read-only.2 params
List payments RECEIVED across the merchant's pay-links (newest first), with cursor pagination. Read-only.
Parameters* required
limitintegerPage size (default 25)
starting_afterstringCursor: last payment id of the previous page
xenarch_list_subscribersList subscribers across the merchant's subscription pay-links, with optional filters (link_id, status, mode). Read-only.5 params
List subscribers across the merchant's subscription pay-links, with optional filters (link_id, status, mode). Read-only.
Parameters* required
modestringreminder | permit | stream
limitintegerPage size (default 50)
statusstringactive | cancelled | pending_email_verification | failed | exhausted
link_idstringFilter by a subscription link
starting_afterstringCursor: last subscription_id of the previous page
xenarch_get_merchant_profileGet the merchant profile (issuer identity, domain verification status). Read-only. Returns null if none is set yet.
Get the merchant profile (issuer identity, domain verification status). Read-only. Returns null if none is set yet.
No parameter schema in public metadata yet.
xenarch_update_merchant_profileUpdate the merchant profile (issuer name, site, email, address, tax id, brand color, logo, payout rhythm). Only the fields you pass change; the rest are preserved (whole-state upsert).8 params
Update the merchant profile (issuer name, site, email, address, tax id, brand color, logo, payout rhythm). Only the fields you pass change; the rest are preserved (whole-state upsert).
Parameters* required
brand_colorstringAccent color, e.g. #5a9fd4
issuer_namestringissuer_emailstringissuer_tax_idstringmerchant_sitestringYour domain, e.g. example.com
issuer_addressstringissuer_logo_urlstringHTTPS logo URL (must match your domain)
collection_rhythmstringone of
daily · weekly · monthly · neverxenarch_verify_domainVerify the merchant's domain via its DNS TXT record at _xenarch.<merchant_site> (XEN-394). Set merchant_site first via xenarch_update_merchant_profile.
Verify the merchant's domain via its DNS TXT record at _xenarch.<merchant_site> (XEN-394). Set merchant_site first via xenarch_update_merchant_profile.
No parameter schema in public metadata yet.
xenarch_pay_linkPay a Xenarch pay-link by id (wrapped x402): fetches the link's payment envelope, settles EIP-3009 USDC on Base, and confirms the payment with the link. Use this for pay.xenarch.com/l/<id> links; use xenarch_pay for arbitrary x402-gated URLs. Pays from the agent wallet (USDC o...2 params
Pay a Xenarch pay-link by id (wrapped x402): fetches the link's payment envelope, settles EIP-3009 USDC on Base, and confirms the payment with the link. Use this for pay.xenarch.com/l/<id> links; use xenarch_pay for arbitrary x402-gated URLs. Pays from the agent wallet (USDC o...
Parameters* required
link_idstringThe Xenarch pay-link id to pay
max_price_usdnumberRefuse to pay if the price exceeds this (default 1.00)
Xenarch — x402 MCP server for AI agent payments
Xenarch is a non-custodial x402 MCP server. AI agents — Claude, Cursor, LangChain, CrewAI — pay for HTTP 402—gated APIs and content with USDC micropayments on Base L2. No API keys, no subscriptions, no credit card on file. The agent wallet never needs ETH; USDC is the only token it ever holds. Payments settle on-chain: agent wallet → publisher wallet, direct. 0% Xenarch fee — there's no Xenarch contract in the money flow.
What makes Xenarch different
| Cloudflare Pay-Per-Crawl | Stripe | TollBit | Vercel x402-mcp | Other x402 MCP servers | Xenarch | |
|---|---|---|---|---|---|---|
| Works on any host | × (Cloudflare only) | ✓ | × (enterprise) | Vercel-first | ✓ | ✓ |
| Non-custodial | × | × | × | platform-routed | varies | ✓ direct USDC transfer |
| Agent needs ETH | n/a | n/a | n/a | varies | varies | ✓ never |
| Fee | platform rate | 2.9% + $0.30 | platform rate | platform rate | varies | 0%, structurally |
| Open standard | proprietary | proprietary | proprietary | x402 | x402 | x402 + pay.json (authored by Xenarch) |
| Publisher monetization | ✓ (Cloudflare-gated) | ✓ (any stack) | ✓ (enterprise only) | × | × | ✓ (any stack) |
How it works
1. Discover xenarch_check_gate("example.com")
→ { gated: true, accepts: [...] }
2. Pay xenarch_pay("example.com")
→ x402-fetch signs an EIP-3009 USDC transferWithAuthorization
→ Settlement goes on-chain
→ Re-fetches the resource with proof of payment
→ { tx_hash, content }
No API keys. No signup. The agent wallet only ever needs USDC — no ETH, no gas coin of any kind. Xenarch never holds funds and there is no Xenarch contract between the agent and the publisher.
MCP tools
29 tools across three groups. Group 1 (discovery & payments) works with just a
wallet. Groups 2 and 3 (control plane + merchant) manage your Xenarch account and
need a SIWE session — run xenarch agent login once (see Account tools auth).
1. Discovery & payments — agent wallet only
| Tool | Description |
|---|---|
xenarch_check_gate | Check if a URL/domain has an x402 payment gate. Returns the accepted payment requirements — price, asset, network, seller wallet. |
xenarch_pay | Pay for an x402-gated URL. Signs an EIP-3009 USDC transfer, settles on-chain, returns the tx hash and the gated content. |
xenarch_pay_link | Pay a Xenarch pay-link by id (pay.xenarch.com/l/<id>): fetches the envelope, settles USDC on Base, confirms with the link. |
xenarch_get_history | View past payments made by this wallet (totals, per-domain, pagination). |
2. Agent control plane — manage your spending agent (SIWE session)
Caps, scope, kill-switch, and API keys for the operator's agent. Privileged
(loosening) operations require confirm: true; tightening is free.
| Tool | Description |
|---|---|
xenarch_agent_login | Browser-wallet sign-in to the control plane. Returns a link; open it, approve, call again to finish. The 7-day session powers every other xenarch_agent_* tool. |
xenarch_agent_status | Agent profile (name, paused state) + spend summary for a period. Read-only. |
xenarch_agent_get_caps | Read spending caps (per-tx, daily, monthly) + remaining headroom. Read-only. |
xenarch_agent_set_caps | Set caps in USD (none disables an axis). Raising/removing a cap needs confirm: true; tightening is free. |
xenarch_agent_reset_day_cap | Reset today's daily-spend counter to the full daily cap. |
xenarch_agent_get_scope | Read scope: default posture (allow/deny) + the rule list. Read-only. |
xenarch_agent_add_scope_rule | Add an allow/deny rule. deny tightens (free); allow loosens (needs confirm). |
xenarch_agent_remove_scope_rule | Remove a rule by id/prefix. Removing a deny loosens scope (needs confirm). |
xenarch_agent_set_default_scope | Set the posture for unmatched URLs. deny tightens; allow loosens (needs confirm). |
xenarch_agent_pause | Kill switch — block all of the agent's payments immediately. No confirm. |
xenarch_agent_resume | Lift the pause (needs confirm). |
xenarch_agent_list_keys | List the agent's xa_live_ API keys (id, label, last-used, revoked). Never returns plaintext. Read-only. |
xenarch_agent_create_key | Issue a new xa_live_ key (plaintext returned once). Needs confirm. |
xenarch_agent_rotate_key | Rotate a key by id/prefix — invalidates the old secret, returns a new one once. Needs confirm. |
xenarch_agent_revoke_key | Permanently revoke a key by id/prefix. Needs confirm. |
xenarch_agent_get_receipts | List the agent's payment receipts with filters (period, status, source, domain). Read-only. |
3. Merchant — get paid (SIWE session)
Create and manage pay-links, see payments and subscribers, set the merchant profile. Same SIWE session as the control plane.
| Tool | Description |
|---|---|
xenarch_create_link | Create a pay-link. VALIDATE-FIRST: mode:'validate' reports missing fields; then mode:'create' + confirm:true signs + creates. Amount is USDC (max 1.00). |
xenarch_list_links | List the merchant's pay-links (newest first), cursor-paginated. Read-only. |
xenarch_get_link | Get one pay-link's detail (status, params, stats) by id. Read-only. |
xenarch_revoke_link | Revoke a pay-link by id so it can no longer be paid. Needs confirm. |
xenarch_list_payments | List payments received across the merchant's links (newest first), cursor-paginated. Read-only. |
xenarch_list_subscribers | List subscribers across subscription links, with filters (link_id, status, mode). Read-only. |
xenarch_get_merchant_profile | Get the merchant profile (issuer identity, domain-verification status). Read-only. |
xenarch_update_merchant_profile | Update the merchant profile (name, site, email, address, tax id, brand color, logo, payout rhythm). Whole-state upsert. |
xenarch_verify_domain | Verify the merchant's domain via its _xenarch.<site> DNS TXT record. Set the site first via xenarch_update_merchant_profile. |
Account tools auth
- Payments (group 1) need a funded wallet (
XENARCH_PRIVATE_KEY) and a control-plane link (XENARCH_API_TOKEN) — the official MCP refuses to pay without the token (XEN-480: an unlinked agent has no caps). A local per-call cap (XENARCH_MAX_PAYMENT_USD, default $1) applies on top of the managed per-tx / daily / monthly caps. - Control plane + merchant (groups 2–3) need a SIWE session. Run
xenarch agent loginonce — it writes a 7-daysession_tokento~/.xenarch/config.json, which the MCP server reads automatically. Re-run when it expires, or callxenarch_agent_logindirectly from your client. - Set
XENARCH_API_TOKEN(anxa_live_agent key) soxenarch_payis enforced against your managed caps/scope and every MCP payment shows up in the dashboard receipts feed. The dashboard is free — sign in with your wallet at dash.xenarch.dev (just a signature, nothing moves) for per-tx / daily / monthly caps, scope rules, a kill switch, and full history. Without the token,xenarch_payrefuses to pay (fail-closed) so an unlinked agent can't settle uncapped. Note: the dashboard sign-in wallet is your identity — separate from the agent's local spending wallet.
Example responses
xenarch_check_gate
{
"gated": true,
"gate_id": "7f3a1b2c-9d4e-4a8b-b6f1-2c3d4e5f6a7b",
"accepts": [
{
"scheme": "exact",
"network": "base",
"maxAmountRequired": "3000",
"resource": "https://example.com/article",
"payTo": "0xabc123...publisher_wallet",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"maxTimeoutSeconds": 60
}
],
"seller_wallet": "0xabc123...publisher_wallet",
"network": "base",
"asset": "USDC"
}
xenarch_pay
{
"success": true,
"gate_id": "7f3a1b2c-9d4e-4a8b-b6f1-2c3d4e5f6a7b",
"tx_hash": "0xdef456...abc789",
"seller_wallet": "0xabc123...publisher_wallet",
"url": "https://example.com/article",
"wallet": "0x123...your_wallet",
"content": "...gated content here..."
}
xenarch_get_history
{
"payments": [
{
"domain": "example.com",
"amount_usd": "0.003",
"tx_hash": "0xdef456...abc789",
"paid_at": "2026-04-10T14:35:00Z"
}
],
"total_spent_usd": "0.003000",
"count": 1,
"wallet": "0x123...your_wallet"
}
HTTP 402 — the unused status code that x402 finally activates
HTTP 402 Payment Required is a status code reserved in the HTTP spec since 1997 for machine-to-machine payment. It went unused for decades because there was no open protocol for how a client should pay a 402 response.
x402 is that protocol: a server returns HTTP 402 with a signed price and payment details, the client signs a USDC micropayment on Base L2, and retries the request with proof of payment. Xenarch's MCP server automates both halves for AI agents — it reads the 402 challenge, signs the payment via x402-fetch, and replays the request, returning the on-chain tx hash plus the gated content.
Learn more: the x402 spec defines the payment handshake; pay.json (authored by Xenarch) is the companion open standard for machine-readable pricing served at /.well-known/pay.json — think robots.txt for payments.
API monetization with HTTP 402
Xenarch is an API monetization primitive built on the HTTP 402 spec. Unlike API gateway monetization platforms (Apigee, Kong, AWS API Gateway) that require subscriptions, dashboards, and API keys, Xenarch lets any API charge per request with no account creation and no key provisioning — the caller pays USDC on Base L2, the API verifies the on-chain transaction, access is granted.
For publishers, this means:
- No integration with Stripe/card processors
- No subscription plans, pricing tiers, or quota dashboards
- No custodial balance held by a platform
- Per-request pricing that works for human users, bots, and AI agents uniformly
- API monetization that settles on-chain in real time
The Python SDK includes a one-decorator FastAPI middleware; see xenarch-sdks/python for publisher integration.
Setup
- Configure your wallet:
mkdir -p ~/.xenarch
cat > ~/.xenarch/wallet.json << 'EOF'
{
"privateKey": "0xYOUR_PRIVATE_KEY"
}
EOF
chmod 600 ~/.xenarch/wallet.json
- Add to Claude Code:
claude mcp add xenarch -- npx @xenarch/agent-mcp
Or add the same JSON to any MCP client's config file:
- Claude Desktop —
~/Library/Application Support/Claude/claude_desktop_config.json(macOS) /%APPDATA%\Claude\claude_desktop_config.json(Windows) - Cursor —
~/.cursor/mcp.json(global) or.cursor/mcp.json(per-project) - Cline (VS Code) — the MCP Servers panel → "Configure MCP Servers", or
cline_mcp_settings.json
{
"mcpServers": {
"xenarch": {
"command": "npx",
"args": ["@xenarch/agent-mcp"],
"env": {
"XENARCH_PRIVATE_KEY": "0xYOUR_PRIVATE_KEY",
"XENARCH_API_TOKEN": "xa_live_…optional, enforces caps/scope"
}
}
}
}
-
Fund the wallet with USDC on Base. That's it — no ETH, no other token needed.
-
(Optional) To use the control-plane + merchant tools, run
xenarch agent loginonce to create a SIWE session.
Environment variables
| Variable | Default | Description |
|---|---|---|
XENARCH_PRIVATE_KEY | — | Wallet private key (overrides config file) |
XENARCH_API_TOKEN | — | Required. Agent xa_live_ key. Enforces xenarch_pay against your caps/scope and feeds the dashboard receipts. Without it, xenarch_pay refuses to pay (fail-closed). |
XENARCH_RPC_URL | https://mainnet.base.org | Base RPC endpoint |
XENARCH_API_BASE | https://xenarch.dev | Xenarch platform API |
XENARCH_NETWORK | base | Network (base or base-sepolia) |
XENARCH_MAX_PAYMENT_USD | 1.00 | Local per-call payment cap (USDC). The only spending ceiling in standalone mode — xenarch_pay refuses any single payment above it. Set 0 to remove the cap. For managed per-tx / daily / monthly caps, connect XENARCH_API_TOKEN. |
The control-plane + merchant tools don't use an env var for auth — they read the
SIWE session_token that xenarch agent login writes to ~/.xenarch/config.json.
Examples
See xenarch-examples for working integration examples — Python agents, LangChain, CrewAI, Claude Desktop setup, and publisher middleware.
Development
npm install
npm run build
Structure
packages/
shared/ — Payment logic, types, config (reused across servers)
agent/ — MCP server for AI agents
FAQ
How does Claude pay for APIs with Xenarch?
Install the Xenarch MCP server (claude mcp add xenarch -- npx @xenarch/agent-mcp), give it a wallet, and Claude resolves any HTTP 402 response automatically with a USDC micropayment on Base L2.
Does Xenarch work with Cursor, LangChain, or CrewAI? Yes. Xenarch exposes an MCP server that any MCP-compatible client can use — Claude Code, Claude Desktop, Cursor, Cline, LangChain, CrewAI, and any other client that speaks Model Context Protocol.
Is FastAPI supported for publishers?
Yes, via the Python SDK (pip install xenarch[fastapi]) — a one-decorator middleware returns HTTP 402 with the price and verifies the on-chain payment. See xenarch-sdks/python.
Is Xenarch custodial? No. Payments settle on-chain as a direct USDC transfer from the agent wallet to the publisher wallet. Funds never touch Xenarch infrastructure and there is no Xenarch contract in the money flow.
Does the agent need ETH for gas? No. USDC is the only token the agent wallet ever needs. Fund it with USDC and you're done — no ETH, no other gas coin.
What's the fee? 0%, structurally. Xenarch never sits in the money flow — there's no Xenarch contract that could charge a fee.
What's the maximum payment per call? $1 USD.
What is x402? x402 is an open protocol for HTTP 402 Payment Required. A server returns 402 with a price, the client signs a USDC micropayment on Base L2 (or other supported chain), and retries the request with proof of payment.
What is HTTP 402? HTTP 402 Payment Required is a status code reserved in the HTTP spec since 1997 for machine-to-machine payment. x402 is the open protocol that finally uses it.
How does Xenarch compare to Cloudflare Pay-Per-Crawl? Cloudflare Pay-Per-Crawl only works for sites behind Cloudflare and is custodial. Xenarch works on any host and is non-custodial — publishers are paid directly on-chain.
How does Xenarch compare to TollBit? TollBit is enterprise-licensing focused. Xenarch is self-serve, non-custodial, and works for the long tail of publishers and any AI agent without enterprise contracts.
Links
- Website: https://xenarch.com
- npm: https://www.npmjs.com/package/@xenarch/agent-mcp
- PyPI: https://pypi.org/project/xenarch/
- Smithery: https://smithery.ai/servers/xenarch/xenarch-mcp
- GitHub: https://github.com/xenarch-ai/xenarch-mcp
License
MIT
Featured
Keep your Mac awake while Claude Code and 40+ AI agents run. Sleeps when they're idle.
One time payment $9 →Integrate web data into your AI product. One API to scrape website & brand data.
Get API Key Now →Agent, run crypto. Access onchain data & trade routes via 1inch.
Install now →On Capafy, your Skill runs online 24/7 as an agent product, and you get paid every time someone uses it.
Start earning →Configuration
XENARCH_PRIVATE_KEYsecretWallet private key (hex, 0x-prefixed). Auto-generates on first run if omitted.
XENARCH_RPC_URLBase RPC endpoint URL
XENARCH_NETWORKNetwork for payments (base or base-sepolia)
XENARCH_AUTO_APPROVE_MAXMax USD to auto-approve without prompting
PORTPort for HTTP server (default: 3000)
TRANSPORT*Set to 'http' to enable HTTP transport
Categories
Registryactive
Package@xenarch/agent-mcp
TransportSTDIO, HTTP
AuthRequired
UpdatedJun 4, 2026
