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Deepfirstsearch MCP Server

Developer ToolsLow Risk10.0MCP RegistryLocal
Free

Server data from the Official MCP Registry

x402 payments in USDC on Base inside an owner-signed, on-chain budget the model can't change

About

x402 payments in USDC on Base inside an owner-signed, on-chain budget the model can't change

Security Report

10.0
Low Risk10.0Low Risk

Valid MCP server (4 strong, 3 medium validity signals). 1 code issue detected. No known CVEs in dependencies. ⚠️ Package registry links to a different repository than scanned source. Imported from the Official MCP Registry. Trust signals: trusted author (3/3 approved). 2 finding(s) downgraded by scanner intelligence.

18 files analyzed · 2 issues found

Security scores are indicators to help you make informed decisions, not guarantees. Always review permissions before connecting any MCP server.

Permissions Required

This plugin requests these system permissions. Most are normal for its category.

HTTP Network Access

Connects to external APIs or services over the internet.

file_system

Check that this permission is expected for this type of plugin.

env_vars

Check that this permission is expected for this type of plugin.

What You'll Need

Set these up before or after installing:

32-byte hex secret the per-merchant payer addresses are derived from. Never your owner key.Required

Environment variable: AGENT_PAY_BURNER_SEED

The budget's agent key (needed when a vault is configured).Required

Environment variable: AGENT_PAY_AGENT_KEY

How to Install

Add this to your MCP configuration file:

{
  "mcpServers": {
    "com-deepfirstsearch-agent-pay-mcp": {
      "env": {
        "AGENT_PAY_AGENT_KEY": "your-agent-pay-agent-key-here",
        "AGENT_PAY_BURNER_SEED": "your-agent-pay-burner-seed-here"
      },
      "args": [
        "-y",
        "@deepfirstsearch/agent-pay-mcp"
      ],
      "command": "npx"
    }
  }
}

Documentation

View on GitHub

From the project's GitHub README.

Deep First Search: safe x402 payments for AI agents

Safe rails for the agent economy. Search deep. Reveal only what you choose.

AI agents now pay for things over x402. Every one of those payments is public, and any agent can be talked into paying the wrong party. Deep First Search makes the model propose payments while the owner's signed policy decides.

npm MCP CI License: MIT

Try it in 10 seconds

No keys, no wallet, no chain: a local x402 merchant plays honest and hostile, and you watch the agent pay for data and refuse four attacks.

npx @deepfirstsearch/agent-pay demo

Pick your path

You useInstallGuide
Claude Desktop, Claude Code, Cursor, any MCP clientnpx @deepfirstsearch/agent-pay-mcpintegrations/mcp
Vercel AI SDKnpm i @deepfirstsearch/agent-pay-ai-sdkintegrations/ai-sdk
LangChain.js / LangGraphnpm i @deepfirstsearch/agent-pay-langchainintegrations/langchain
Your own agent, any walletnpm i @deepfirstsearch/agent-paysdk
On-chain budgets on Basenpx @deepfirstsearch/agent-pay owner helpowner CLI

Full developer guide: deepfirstsearch.com/developers · building a wallet, framework or platform? Partners.

What's in this repository

ComponentWhat it doesStatus
MCP server (integrations/mcp/)Model Context Protocol server: Claude Desktop, Claude Code, Cursor and any MCP client get paid_fetch, list_merchants and budget_status tools that pay x402 APIs inside the owner's budget✅ npx @deepfirstsearch/agent-pay-mcp · tested with a real Claude session on Base Sepolia
Agent Safe (contracts/)On-chain vault: owner-signed, timelocked, per-merchant budgets; the agent key can spend but never widen✅ 98 tests (fuzzing, invariants, properties, regressions, Base mainnet fork with real USDC), two internal reviews · live on Base mainnet (beta)
agent-pay SDK (sdk/)x402 v2 client with a policy engine outside the model, prompt-injection guards, per-merchant payers, owner CLI✅ 162 tests incl. on-chain loops and the official x402 facilitator · npx @deepfirstsearch/agent-pay owner …
Framework tools (integrations/)Vercel AI SDK paidFetchTool, LangChain/LangGraph createPaidFetchTool✅ on npm
$DEPTH (contracts/)1B fixed supply, no mint function, no owner; fees burned through a fee jar + firepit✅ Implemented · not launched
Website (web/)Site, whitepaper, tokenomics, partner kit, legal pages; strict CSP, zero third parties✅

MCP server: let Claude or Cursor pay x402 APIs safely

@deepfirstsearch/agent-pay-mcp is a stdio MCP server. The model gets three tools and nothing that can move money on its own terms:

MCP toolWhat it does
paid_fetch(url, method?, body?, contentType?)Fetches a URL; if it answers 402 Payment Required, pays in USDC on Base only when the merchant, price and budget match your config
list_merchants()Merchants the agent may pay, their prices and the remaining budget
budget_status()Remaining budget per merchant, plan window, vault balance
{ "mcpServers": { "agent-pay": {
    "command": "npx", "args": ["-y", "@deepfirstsearch/agent-pay-mcp", "/path/config.json"],
    "env": { "AGENT_PAY_AGENT_KEY": "0x…", "AGENT_PAY_BURNER_SEED": "0x…" } } } }

Payees, prices and limits come from the config file and the owner-signed on-chain budget, never from the model or a 402 response, so a prompt-injected agent can't overspend or pay an attacker. Setup, config reference and a 5-minute Base Sepolia demo: integrations/mcp.

Status: pre-launch. Live on Base Sepolia, with a real x402 payment settled (see deployments); unaudited beta on Base mainnet since 2026-10-06 (small amounts, our own funds first, then invited design partners) while we arrange an independent audit; the public launch comes after the audit. No token exists.

Develop on this repository

# Contracts (needs Foundry: curl -L https://foundry.paradigm.xyz | bash && foundryup)
git submodule update --init --recursive
cd contracts && forge test

# SDK
cd ../sdk && npm ci && npm test && npm run demo

# Website
cd ../web && npm ci && npm run dev

Documents

WhitepaperFormal design, privacy model, risks (EN; structured for MiCA Annex I)
TokenomicsSupply, allocation, Firepit burn, vesting (EN)
DecisionsADRs: ticker, chain, burn, vesting, stand… (ES)
DeploymentsBase Sepolia contract addresses and the live demo vault
Audit scopeScope, nSLOC, roles, known issues and questions for reviewers
Airdrop toolBuilds the airdrop Merkle tree and proofs; tested against the contract
Mainnet runbookSafes, rehearsal, deploy, checks, guarded launch, monitoring
Security assessmentPentest findings, threat model, evidence (ES)
ResearchMarket pain, successes, failures, token models, launch mechanics (ES)

Key decisions

  • Ticker: $DEPTH.
  • Chain: Base.
  • Founder: 12%, nothing for 12 months, then 36 months linear, on-chain; the vesting contract cannot be transferred and the beneficiary is a public Safe.
  • Burn: burn-to-claim fee jar (no swaps, oracles or admins), fed only by Agent Safe, SDK and inference fees, never by privacy-pool fees.
  • No conference booth until there are users; hackathons instead.
  • No own privacy pool: integrate a third-party compliant one (ADR-011). Sales geo-blocked for the US and Argentina (ADR-012).

Security

See SECURITY.md to report vulnerabilities.

Contact

Built by Nicolas Tursi. General contact: hello@deepfirstsearch.com. Security reports: see SECURITY.md or write to security@deepfirstsearch.com.

License

MIT (contracts and SDK).

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