x402-bazaar-mcp

The Base token-safety toolkit for AI agents. An MCP (Model Context Protocol) server that gives your agent the checks it needs before it touches a Base token — including the only B20 (Base-native token standard) freeze/seize/rug suite anywhere, pre-trade GO/HOLD/STOP gates, honeypot & sellability checks, wallet + approval audits, sign-guard, prices and AI reports. Every paid API in the x402 Bazaar catalog, exposed as a callable tool (Claude Desktop, Cursor, Cline, Windsurf, VS Code, Coinbase AgentKit, custom agents).

Bind these first: pre_trade_gate (any token), b20_gate (Base-native B20 tokens), sign_guard (before signing a tx).

Each tool call is backed by an x402 micro-payment in USDC on Base — no API keys, no subscriptions, no sign-up. The agent pays only for what it uses, typically fractions of a cent per call.

Works with zero config. Run it with no wallet and no token and it uses the free tier (one free call/day per service, then a preview) — so an agent can try every tool instantly. Unlock unlimited paid calls with either a prepaid credit token (one x402 purchase up front, then no wallet or signing per call) or a wallet key.

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How it works

1. On startup the server fetches the live catalog from https://402.com.tr/api/catalog and auto-registers one MCP tool per service.
2. When an AI agent calls a tool the server picks a payment mode (below), hits the endpoint, and returns the response.
3. In wallet mode the x402 flow is transparent: HTTP 402 → pay USDC on Base → retry → return response, gasless for the payer (the facilitator pays gas).

Three payment modes (precedence order)

Mode	Set	What happens	Wallet? Signing?
Credits ⭐	X402_CREDIT_TOKEN	Sent as x-credit-token; each call debits your prepaid balance	No / No
Wallet	AGENT_PRIVATE_KEY	Signs an x402 USDC payment locally per call	Yes / Yes
Free	(nothing)	Free tier: 1 full call/day/service, then a preview	No / No

Credits are the easiest paid mode day-to-day: buying the pack takes ONE x402 settlement (call the buy_credits tool in wallet mode, or pay https://402.com.tr/api/x402/buy-credits?tier=0.25|1|5|20 from any x402 client), which returns a ck_… token. Set it as X402_CREDIT_TOKEN and every later call just draws down the balance — no private key ever touches this config again. Tiers: $0.25 starter, $1, $5 (+10%), $20 (+20%).

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Requirements

• Node.js ≥ 20
• (optional, for paid calls) a prepaid credit token or a Base wallet private key whose address holds USDC on Base mainnet

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Installation & running

npm install

# Zero-config — free tier, try every tool instantly:
npx x402-bazaar-mcp

# Paid via prepaid credits (recommended — no wallet, no signing):
X402_CREDIT_TOKEN=ck_your_token npx x402-bazaar-mcp

# Paid via wallet:
AGENT_PRIVATE_KEY=0xYOUR_PRIVATE_KEY npx x402-bazaar-mcp

Environment variables

Variable	Required	Default	Description
X402_CREDIT_TOKEN	no	—	Prepaid credit token (ck_…) from buy-credits. Sent as x-credit-token; debits your balance per call. No wallet needed. Recommended paid mode.
AGENT_PRIVATE_KEY	no	—	Hex private key for a Base wallet holding USDC. 0x prefix optional. Used only if no credit token is set.
X402_BAZAAR_CATALOG	no	https://402.com.tr/api/catalog	Override the catalog URL (useful for local dev).

With none of the above set, the server runs on the free tier.

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Claude Desktop configuration

Add the following to your claude_desktop_config.json (usually ~/Library/Application Support/Claude/claude_desktop_config.json on macOS or %APPDATA%\Claude\claude_desktop_config.json on Windows):

{
  "mcpServers": {
    "x402-bazaar": {
      "command": "npx",
      "args": ["-y", "x402-bazaar-mcp"],
      "env": {
        "X402_CREDIT_TOKEN": "ck_your_token"
      }
    }
  }
}

Omit the env block entirely to run on the free tier (great for a first try), or use "AGENT_PRIVATE_KEY": "0x…" instead of the credit token to pay from a wallet.

After saving, restart Claude Desktop. You should see the Bazaar tools appear in the tool list (hammer icon).

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Cursor

Add to ~/.cursor/mcp.json (global) or .cursor/mcp.json in your project:

{
  "mcpServers": {
    "x402-bazaar": {
      "command": "npx",
      "args": ["-y", "x402-bazaar-mcp"],
      "env": { "X402_CREDIT_TOKEN": "ck_your_token" }
    }
  }
}

Cline (VS Code)

In the Cline panel → MCP Servers → Configure (cline_mcp_settings.json):

{
  "mcpServers": {
    "x402-bazaar": {
      "command": "npx",
      "args": ["-y", "x402-bazaar-mcp"],
      "env": { "X402_CREDIT_TOKEN": "ck_your_token" },
      "disabled": false,
      "autoApprove": []
    }
  }
}

Windsurf

Add to ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "x402-bazaar": {
      "command": "npx",
      "args": ["-y", "x402-bazaar-mcp"],
      "env": { "X402_CREDIT_TOKEN": "ck_your_token" }
    }
  }
}

VS Code (GitHub Copilot / MCP)

Add to .vscode/mcp.json in your workspace (or run MCP: Add Server):

{
  "servers": {
    "x402-bazaar": {
      "command": "npx",
      "args": ["-y", "x402-bazaar-mcp"],
      "env": { "X402_CREDIT_TOKEN": "ck_your_token" }
    }
  }
}

Every client above works the same way: omit env to run on the free tier, or swap the credit token for "AGENT_PRIVATE_KEY": "0x…" to pay from a wallet.

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Use with Coinbase AgentKit, Agentic Wallet & Claude Code

Because this is a standard MCP stdio server, any MCP-capable agent runtime can load and pay for the Bazaar's tools — including Coinbase's own agent stack, with no bespoke integration:

Coinbase Agentic Wallet (npx awal)

Coinbase Agentic Wallets ship native x402 support and an MCP interface. Point the wallet's MCP config at npx x402-bazaar-mcp, and the agent can call — and pay for — any Bazaar service straight from its MPC-secured wallet, gasless on Base. The x402 payment handshake is handled for you: HTTP 402 → pay USDC on Base → retry → response.

Coinbase AgentKit

Two ways in:

1. As MCP tools — load this server into your AgentKit agent's MCP config (command: "npx", args: ["-y", "x402-bazaar-mcp"], and X402_CREDIT_TOKEN or AGENT_PRIVATE_KEY in env). The agent gains all 80+ Bazaar tools — B20 freeze/seize checks, pre-trade gates, honeypot/sellability, deployer reputation, exit liquidity, live DEX prices, gas, tx decode, Claude reports — as pay-per-call actions, no action provider to write.
2. Via AgentKit's native x402 support — AgentKit's wallet can settle x402 payments directly, so an agent can GET https://402.com.tr/api/x402/<service> and pay the returned 402 from its own wallet. The 402 body includes a machine-readable alternatives block (starter credits first) so the agent can pick the cheapest on-ramp programmatically.

Either way the agent pays only for the calls it makes, in USDC on Base, gasless.

Claude Code

Add it as an MCP server in one command:

# Free tier (zero config):
claude mcp add x402-bazaar -- npx -y x402-bazaar-mcp

# Or paid via prepaid credits:
claude mcp add x402-bazaar -e X402_CREDIT_TOKEN=ck_your_token -- npx -y x402-bazaar-mcp

Then ask Claude Code to check a token, price a portfolio, or screen an address — it calls the right Bazaar tool and settles the micro-payment automatically.

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Why agents use this

Agents need fresh on-chain data and AI utilities but don't want to manage RPC endpoints, scrapers, security heuristics, or per-provider API keys. One MCP server plus a credit token (or a funded wallet) gives them everything — contract safety checks, live DEX prices, gas estimates, transaction decoding, and Claude-powered reports — all pay-per-use, with no subscriptions or sign-up required.

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What your agent can do (tools)

Tools are loaded live from the catalog, so the list stays current. At the time of writing it includes:

Tool	Price	What it does
pre_trade_gate	$0.10	The one call before a trade — risk + sellability + route + deployer → GO/HOLD/STOP
token_risk	$0.03	Token safety score (honeypot, taxes, ownership, holders) for any Base token
sellability	$0.08	Can you actually SELL it? Honeypot/tax/lp simulation verdict
ai_token_report	$0.12	Claude-written full due-diligence report on a token
sanctions	$0.02	Screen an address against the OFAC sanctions list
holders	$0.02	Top holders, concentration (whale risk) & LP lock for a token
token_price	$0.02	DEX price + liquidity for a Base token
multi_price	$0.02	Prices for up to 10 Base tokens in one call
address_intel	$0.02	EOA/contract, ETH+USDC balance, activity for any address
wallet_tokens	$0.02	Portfolio of major Base tokens + USD value
gas_oracle	$0.01	Live Base gas estimates (slow/normal/fast)
tx_decode	$0.02	Structural decode of a Base transaction
contract_abi	$0.02	Is a contract verified? Get its ABI (Sourcify)
basename	$0.01	Resolve Basenames ↔ addresses on Base
trending_tokens / new_tokens	$0.01	Trending & freshly listed Base tokens
price_alert	$0.05	Register an alert when a token crosses a price (webhook or poll)
buy_credits	$0.25–$20	Buy a prepaid credit pack (tier param) — unlocks walletless calls

Prices shown as of this release — the authoritative price is always in the live catalog and in each 402 challenge. …plus ~50 more tools loaded live from the catalog (66 total), including whale_flow, watchlist_diff and the 8-tool B20 safety suite.

Example

Once installed, just ask your agent naturally — it picks the right tool and pays per call:

"Is 0x… a safe token to buy on Base? Check the risk and current price."

The agent calls token_risk and token_price, each settling a tiny USDC payment from your wallet, and answers with the on-chain data.

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Sample outputs

token_risk — low-risk token

{
  "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "isContract": true,
  "token": {
    "name": "USD Coin",
    "symbol": "USDC",
    "decimals": 6,
    "totalSupply": "4800000000000000"
  },
  "ownership": {
    "owner": "0x0000000000000000000000000000000000000000",
    "renounced": true
  },
  "upgradeableProxy": false,
  "security": {
    "isHoneypot": false,
    "buyTaxPct": 0,
    "sellTaxPct": 0,
    "isOpenSource": true,
    "isMintable": false,
    "transferPausable": false,
    "canTakeBackOwnership": false,
    "hiddenOwner": false,
    "holderCount": 182430,
    "topHolderPct": 12.47,
    "top10HolderPct": 41.22,
    "lockedLpPct": 100,
    "creatorPct": 0,
    "isInDex": true,
    "isAntiWhale": false,
    "antiWhaleModifiable": false,
    "tradingCooldown": false,
    "slippageModifiable": false,
    "isTrueToken": true,
    "isAirdropScam": false,
    "creatorAddress": "0x6B175474E89094C44Da98b954EedeAC495271d0F",
    "creatorBalance": "0"
  },
  "riskScore": 0,
  "riskLevel": "low",
  "flags": [],
  "sources": ["base-rpc", "goplus"],
  "coverage": "RPC base + GoPlus security (honeypot, taxes, holders, holder concentration, LP lock, creator holdings, source, ownership controls).",
  "checkedAt": "2026-06-23T09:14:02.381Z"
}

token_price — DEX price and liquidity

{
  "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "priceUsd": "0.9998",
  "priceChange24h": -0.03,
  "liquidityUsd": 4721850.44,
  "volume24h": 18340210.77,
  "dexId": "uniswap",
  "pairAddress": "0x88A43bbDF9D098eEC7bCEda4e2494615dfD9bB9C",
  "baseToken": {
    "name": "USD Coin",
    "symbol": "USDC"
  },
  "checkedAt": "2026-06-23T09:14:03.105Z"
}

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Discovering available services

• Human-readable catalog & docs: https://402.com.tr/agents
• Machine-readable catalog (used by this server): https://402.com.tr/api/catalog
• x402 well-known: https://402.com.tr/.well-known/x402

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Security note

Prepaid credits (recommended) keep wallets out of your agent config — buying the pack takes one x402 settlement, but after that the ck_… token is all the agent holds: a bearer capability worth only its remaining balance, so a leaked token can lose at most what's left on it, never a wallet. Buy a small pack and rotate it if needed.

If you use wallet mode instead, your private key is only used locally inside this process to sign payment authorizations. It is never sent to the Bazaar server or any third party. Use a dedicated spending wallet (not your main wallet) and keep only a small USDC balance on it.

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License

MIT