# IntentFence Payment Firewall [Health: Active] **Category:** 💰 Finance & Fintech **Repository:** https://github.com/razel369/intentfence **GitHub Stars:** 2 **Views:** 0 **Installs:** 0 **Upvotes:** 0 **Directory Page:** https://allmcps.com/mcp/intentfence-payment-firewall ## Description Signed U.S. CPI data, Base wallet risk, x402 quote checks, and payment preflights for AI agents. ## Claude Desktop Quick Installation Install path detected from listing signals. Uses `npx` (confidence: high): ```json "mcpServers": { "intentfence-payment-firewall": { "command": "npx", "args": ["-y","skills"] } } ``` ## Documentation & README # IntentFence IntentFence is a fail-closed authorization firewall for autonomous AI agents. Immediately before a consequential MCP, HTTP, A2A, or payment action, it binds the exact action and payload hash to explicit action/resource allowlists, spend and retention ceilings, and optional action-specific approval. It returns a five-minute ES256 receipt; the TypeScript and Python SDKs verify the receipt and local action digest before executing the caller-owned callback. IntentFence never executes downstream tools and should never receive credentials or wallet keys. It also provides MCP metadata scanning and x402 payment-safety checks. - `safe_to_proceed` - `needs_review` - `denied` Production: x402scan: Official MCP Registry: [![razel369/intentfence MCP server](https://glama.ai/mcp/servers/razel369/intentfence/badges/score.svg)](https://glama.ai/mcp/servers/razel369/intentfence) ## Protocol surfaces | Surface | Endpoint | | --- | --- | | Action-bound authorization | `POST /api/actions/authorize` | | Paid self-service production policy pack | `POST /api/policy-packs` | | Free MCP metadata risk scan | `POST /api/agent-risk/scan` | | Free REST preview | `POST /api/preflight` | | Paid x402 decision | `POST /api/preflight/verified` | | Paid caller-observed x402 quote assessment | `POST /api/x402-assessments` | | Paid live x402 endpoint readiness | `POST /api/x402-readiness` | | Paid live Base wallet-risk assessment | `GET /api/wallet-risk?address=...` | | Paid signed official U.S. CPI data | `GET /api/us-cpi?month=YYYY-MM` | | Receipt verification | `POST /api/receipts/verify` | | Public ES256 keys | `GET /.well-known/jwks.json` | | MCP Streamable HTTP | `/api/mcp` (`intentfence_verified_preflight` is x402-paid) | | A2A Agent Card | `GET /.well-known/agent-card.json` | | x402 service manifest | `GET /.well-known/x402` | | Public aggregate metrics | `GET /api/metrics` | | OpenAPI | `GET /openapi.json` | ## Fail-closed action authorization The hosted MCP tools `intentfence_authorize_action` and `intentfence_agent_risk_scan` are available without an API key and are rate-limited. Authorization signs the exact caller-supplied action and policy digests for five minutes but does not validate the truth of a self-declared identity or approval source. Production callers must verify the receipt, re-hash the local action, and block on denial, review, expiry, mismatch, network failure, or verification failure. Use the TypeScript `enforceAction` or Python `run_authorized` helper to make that boundary executable. The scanner evaluates caller-supplied MCP metadata only. It highlights missing schemas, annotations, action-bound approval, and financial limits, but does not execute tools, inspect source code, or certify security or compliance. Official U.S. CPI costs 0.001 USDC; live readiness and wallet risk cost 0.002 USDC; signed preflight and exact-quote assessment cost 0.005 USDC on Base through x402. A successful call returns both the facilitator's `PAYMENT-RESPONSE` settlement header and an IntentFence ES256 compact-JWS receipt. Wallet risk is the recommended first check before paying a Base recipient. It uses live Base RPC activity and GoPlus malicious-address intelligence. A `safe_to_proceed` result means no listed malicious flags were observed and the address was established on Base at assessment time; it does not prove identity, ownership, authorization, or future behavior. Install the recurring pre-payment skill to attach that check to new Base recipients: ```bash npx skills add razel369/intentfence --skill screen-base-wallets ``` The skill can run without interrupting an autonomous workflow only when the wallet owner already approved a standing 0.002 USDC screening budget and the wallet enforces it. It blocks the downstream payment on review, denial, missing settlement proof, invalid receipt, or service failure. The live readiness check is the simplest first call when an agent only has an endpoint URL. It makes one bounded credential-free request, rejects private-network targets and redirects, validates the returned challenge, never pays the target, and signs the result for five minutes. The quote assessment is the recommended check after an x402 merchant returns its unpaid challenge and before the agent signs the merchant payment. The agent supplies `subject`, `target_url`, optional `method` (`GET`, `HEAD`, or `POST`), the base64 `payment_required` header (maximum 16 KiB), and a policy with `max_price_usdc` plus an optional `allowed_payees` list. IntentFence validates x402 v2, exact scheme, Base mainnet, canonical Base USDC, price, payee, and exact resource binding. It requires the canonical USDC EIP-712 domain and sends Permit2, unknown transfer metadata, and active extensions to review. A `safe_to_proceed` result requires an explicit matching `allowed_payees` entry; omitting the list yields `needs_review`. IntentFence never fetches or pays the target. Every advertised payment option must satisfy every automatic check; mixed safe and unsafe option sets are denied. ## Self-service production policy pack An agent or developer can buy a complete production guard without an account, email, meeting, or sales call: ```text POST /api/policy-packs ``` The request selects `openai-agents-js`, `cloudflare-agents`, `coinbase-agentkit`, or `mcp-gateway` and supplies one exact action plus its allowlists, spend ceiling, retention limit, and optional approval policy. The first request returns an x402 challenge for exactly 1 USDC on Base. After settlement, the same response delivers a copy-ready TypeScript guard, signed action and policy receipt, allowed/denied/over-budget test vectors, and a fail-closed deployment checklist. The buyer must review the generated code and keep all credentials in its own runtime. ## Install now The hosted MCP endpoint is available without an API key: ```text https://agentpass-protocol.rmalka06.chatgpt.site/api/mcp ``` ### Install the local stdio MCP package Agents and MCP clients that require a local process can run the immutable public 0.11.0 release directly. This does not require an npm account, repository clone, or IntentFence API key: ```bash npx --yes --package https://github.com/razel369/intentfence/releases/download/mcp-v0.11.0/razel369-intentfence-mcp-0.11.0.tgz intentfence-mcp ``` The release artifact is built and tested by GitHub Actions. Its SHA-256 digest is `f0cdf3df28da8a5c037e48193cbb4602744b5fb0b6c182d877abedb707b1e9f9`. Use the hosted endpoint above when the client supports Streamable HTTP. ### Install in an agent runtime - [OpenAI Agents SDK fail-closed guard](https://github.com/razel369/intentfence/blob/HEAD/integrations/openai-agents-js) - [Cloudflare Agents fail-closed guard](https://github.com/razel369/intentfence/blob/HEAD/integrations/cloudflare-agents) - [Coinbase AgentKit pinned x402 checkout](https://github.com/razel369/intentfence/blob/HEAD/integrations/coinbase-agentkit) - [Generic MCP gateway guard](https://github.com/razel369/intentfence/blob/HEAD/integrations/mcp-gateway) All adapters keep credentials in the caller runtime and execute the downstream action only after the exact local action digest and ES256 receipt verify. #### Opt-in one-call payment for local agents The local stdio package can handle the x402 challenge, sign it, retry the tool call, and return the settled result without requiring special MCP-client support. Automatic payment is disabled unless all three values below are set: ```text INTENTFENCE_EVM_PRIVATE_KEY= INTENTFENCE_MAX_AUTO_PAYMENT_USDC=0.005 INTENTFENCE_AUTO_PAYMENT_BUDGET_USDC=0.05 ``` Supply the key through the agent runtime's secret manager or process environment; never commit it to an MCP configuration file. The package signs only `exact` Base-mainnet USDC requirements addressed to the published IntentFence recipient, rejects any payment above the per-call ceiling, and reserves every attempted signature against the process-lifetime budget before signing. Failed attempts remain reserved, so retry loops and concurrent calls cannot exceed the cap. The private key stays in the buyer's local process and is never sent to IntentFence. #### Build an exact machine checkout Agents do not need to infer which endpoint, method, payload, or payment cap matches a product. Read the catalog, then submit the exact product input: ```bash curl https://agentpass-protocol.rmalka06.chatgpt.site/api/checkout curl -X POST https://agentpass-protocol.rmalka06.chatgpt.site/api/checkout \ -H "Content-Type: application/json" \ -d '{"product":"wallet-risk","input":{"address":"0x1111111111111111111111111111111111111111"}}' ``` The checkout response is free and never initiates payment. It returns a validated HTTP request, shell-safe Agentic Wallet argv, POSIX and PowerShell commands, Coinbase Agentic Wallet MCP instructions, an `mcpc --x402` call, the matching Agent Skill, the matching MCP tool and arguments, and an exact Base USDC ceiling. Paid MCP tools advertise `_meta.x402` for clients that can sign before the first tool call. Agents must still review and authorize the payment and require `PAYMENT-RESPONSE` settlement proof. ### Install in VS Code [Open the live install panel](https://agentpass-protocol.rmalka06.chatgpt.site/#vscode-install), then select **Install IntentFence in VS Code**. The install action contains only the public server name, transport, and URL. VS Code asks you to review and trust the server before its first start. The free policy-preview tool works with no API key. Paid calls through the hosted server need an x402-capable client; runtimes without one can use the budget-capped local stdio mode above. Manual `.vscode/mcp.json` or user-profile fallback: ```json { "servers": { "IntentFence": { "type": "http", "url": "https://agentpass-protocol.rmalka06.chatgpt.site/api/mcp" } } } ``` Review the server details yourself before starting a manually configured server. See the [official VS Code MCP installation documentation](https://code.visualstudio.com/api/extension-guides/ai/mcp#create-an-mcp-installation-url). ### Install the cross-agent payment guard Install the open Agent Skill in Codex, Claude Code, Cursor, Gemini CLI, GitHub Copilot, and other skills-compatible agents: ```bash npx skills add razel369/intentfence --skill guard-x402-payments ``` [Review the complete skill before installing it](https://github.com/razel369/intentfence/tree/main/skills/guard-x402-payments). The skill triggers when an agent is about to sign an x402 payment. It teaches the agent to capture the exact quote, enforce a caller-defined ceiling and payee allowlist, keep wallet credentials local, and use IntentFence only after the 0.005 USDC assessment fee is authorized. It includes a capped Coinbase Agentic Wallet buyer path for agents that already use an authenticated wallet. Agents that have only a public x402 URL can install the narrower live-readiness skill. It probes the route without credentials or target payment, blocks redirects and private-network targets, validates the returned challenge, and requires explicit authorization before the 0.002 USDC IntentFence fee: ```bash npx skills add razel369/intentfence --skill inspect-x402-endpoints ``` The official x402 client buyer example verifies the live fee challenge before creating a signer and is payment-disabled by default: Agents that already use Coinbase Agentic Wallet can retrieve a complete capped checkout from `GET /api/payments` under `buyer_quickstart`. The published command is pinned to a verified CLI version, includes a valid policy body, and sets `--max-amount 5000` so it cannot authorize more than the 0.005 USDC IntentFence fee. Review the body and explicitly authorize the real payment before running it. Projects that already own a Coinbase AgentKit EVM wallet can use the [pinned AgentKit adapter](https://github.com/razel369/intentfence/tree/main/integrations/coinbase-agentkit). Unlike an automatic retry, it binds the payment to the exact IntentFence URL, Base network, canonical USDC asset, 5000-atomic-unit amount, and recipient, then calls the buyer's own authorization function before signing. The matching machine-readable manifest is published at . Gemini CLI can install the repository directly, without waiting for an npm package or gallery crawl: ```bash gemini extensions install https://github.com/razel369/intentfence ``` The extension starts a dependency-free local MCP bridge and exposes the free preview plus the x402-paid verified preflight and quote-assessment tools. ## Caller-observed x402 quote assessment The first call returns the standard `PAYMENT-REQUIRED` challenge for the IntentFence fee: ```bash curl -i -X POST https://agentpass-protocol.rmalka06.chatgpt.site/api/x402-assessments \ -H "Content-Type: application/json" \ -d '{"subject":"agent:buyer-07","target_url":"https://merchant.example/api/paid-resource","method":"GET","payment_required":"BASE64_PAYMENT_REQUIRED_HEADER","policy":{"max_price_usdc":"0.10","allowed_payees":["0x1111111111111111111111111111111111111111"]}}' ``` Retry the same request with a valid x402 v2 `PAYMENT-SIGNATURE`. A successful response contains the validated caller-observed challenge fields, pass/review/deny checks, a SHA-256 binding to the full target URL and exact payment requirement, and an ES256-signed assessment receipt. The assessment uses assurance `caller-observed-x402-quote-assessment` and verification tier `x402-quote-assessment+x402-settled`; x402 settlement covers the 0.005 USDC IntentFence assessment fee, not the target payment. ## Live Base wallet risk The first call returns an x402 challenge for 0.002 USDC: ```bash curl -i "https://agentpass-protocol.rmalka06.chatgpt.site/api/wallet-risk?address=0x1111111111111111111111111111111111111111" ``` Retry the same URL with a valid x402 v2 `PAYMENT-SIGNATURE`. The successful response includes Base account activity, native and USDC balances, a code hash for contracts, current malicious-address flags, pass/review/deny checks, and a five-minute ES256 receipt with assurance `live-base-wallet-risk`. If a required live source is unavailable, the endpoint fails closed and does not intentionally settle the assessment fee. ## Important trust boundary Declared-input receipts attest only that IntentFence evaluated caller-supplied policy data. Quote-assessment receipts bind the exact caller-observed `PAYMENT-REQUIRED` challenge; they do not prove that IntentFence contacted the merchant, or prove merchant identity, delivery, or downstream enforcement. The receipt-signing key is separate from the USDC recipient wallet. IntentFence never needs a payer's seed phrase or wallet private key. Wallet-risk receipts report observed evidence at one point in time and are not identity attestations. ## Local development ```bash npm install npm run dev ``` For MCP clients that launch local `stdio` servers, use `npm run mcp:stdio`. Glama and other container-based hosts can build the root `Dockerfile`; it starts the same IntentFence policy engine and responds to MCP initialization, `tools/list`, and `tools/call` requests over standard input/output. ```bash docker build -t intentfence-mcp . docker run --rm -i intentfence-mcp ``` The production signing key is stored in Sites as the secret `INTENTFENCE_SIGNING_PRIVATE_JWK`. Generate a separate development key with: ```bash node scripts/generate-signing-key.mjs /secure/path/intentfence-private-jwk.json ``` Never commit the generated private JWK. Publish only its public coordinates in `/.well-known/jwks.json`. ## Validation ```bash npm run test npm run lint npx tsc --noEmit npm run sdk:check npm run smoke:mcp:docker npm run smoke:mcp:stdio npm run smoke:protocol -- http://localhost:3000 ``` Set `INTENTFENCE_TEST_PRIVATE_JWK_PATH` only for a local smoke test that should exercise the signed-receipt verifier. ## Distribution TypeScript and Python SDKs live in `sdk/`. The root `server.json` is ready for the official MCP Registry under `io.github.razel369/intentfence`; the public MCP endpoint uses Streamable HTTP and requires no API key. The `/.well-known/x402` service manifest and Bazaar metadata make both paid endpoints crawlable by x402 indexes and autonomous tool routers. Production resources are continuously checked, and the original verified-preflight route is registered on x402scan. Production uses PayAI by default. When both `CDP_API_KEY_ID` and `CDP_API_KEY_SECRET` are configured in the hosted runtime, verification and settlement switch to Coinbase CDP. That makes successful Bazaar-enabled route settlements eligible for Coinbase Bazaar indexing; configuration alone does not create a listing or count as customer revenue. ## Commercial path The fastest no-contact path to production is the 1 USDC policy pack for one guarded purchase, transfer, booking, deployment, deletion, or other consequential action. The machine-readable offer and capped Agentic Wallet checkout are published by `GET /api/payments`. See [docs/PROTOCOL.md](https://github.com/razel369/intentfence/blob/HEAD/docs/PROTOCOL.md) and [docs/SECURITY.md](https://github.com/razel369/intentfence/blob/HEAD/docs/SECURITY.md) for the protocol and security model.