PayStage Preflight

io.github.base-buzz由 GitHub 账号 base-buzz 发布v0.2.3更新于 Nov 12, 2026

Evaluate x402 PaymentRequired against a local spending policy before an agent pays

发布方自己的服务：Preflight

已验证STDIO仅桌面金融安全与监控

服务详情

标识符: io.github.base-buzz/preflight
传输: STDIO
运行时: Desktop only
信任: Verified
发布于: Nov 12, 2026

安全提示

MCP 服务会接收对话中的工具调用请求，并可能执行外部操作。启用前请先了解该服务能做什么，并只授予它所需的权限。

注册中心已验证此条目所属的 GitHub 账号 base-buzz。这并不表明该账号就是产品方。

SourceWeft 的检查只涵盖条目是否完整、端点是否响应；不审查服务器的代码，也不审查其工具的行为。

在 README 中添加徽章

向读者展示该 MCP 服务已收录于 SourceWeft，徽章链接到本页。

[![Listed on SourceWeft](https://sourceweft.com/badge/mcp/io.github.base-buzz%2Fpreflight.svg)](https://sourceweft.com/mcp/io.github.base-buzz%2Fpreflight?utm_source=readme&utm_medium=badge)

概览

AI 生成的概览

本地 stdio MCP 服务器，在代理付款前用 JSON 消费策略校验 x402 PaymentRequired 载荷，返回 pay、review 或 do_not_pay。

可以做什么: 评估付款请求：用本地策略校验 x402 PaymentRequired 载荷，得到 pay、review 或 do_not_pay 三种结论之一。
套用消费规则：允许的网络、资产与收款地址，单次与单会话金额上限，人工审核阈值，以及最大超时。
将格式错误或违反策略的请求判为 do_not_pay，将超过人工阈值的请求判为 review。
适用场景: 当代理能够发起 x402 付款，而你想在资金流出前用确定性的本地检查拦截或升级不符合规则的付款时使用。
运行要求: 需要 Node.js 与 npx 以 stdio 方式在本地运行该 npm 包，并需要一个策略 JSON 文件，其绝对路径通过 PAYSTAGE_POLICY_PATH 指定。判定过程不需要账号、API 密钥或网络访问。

安装前请注意

结论只是建议：它本身不付款也不托管资金，客户端必须真正遵守 pay、review 与 do_not_pay。策略写错（网络、资产、收款地址或上限）会直接改变被批准的付款，请仔细核对策略文件。README 说明该包会读取策略文件与 PAYSTAGE_POLICY_PATH，并提到相关包使用 PAYSTAGE_RPC_URL。

安装

在 SourceWeft 中

打开控制台中的 PayStage Preflight，将其添加到工作区。
为需要使用其工具的对话启用该服务。

Desktop only，通过 STDIO。 STDIO 服务会启动本地进程，因此需要 SourceWeft 桌面宿主。

其他 MCP 客户端

参照仓库中的启动说明。

README

@paystage/preflight

Evaluate an x402 PaymentRequired against a local spending policy before your agent pays. Returns one of three verdicts: pay, review, or do_not_pay.

Local-first — policy lives in a JSON file on your machine. No secrets, no network calls to decide.
MCP-native — runs as a stdio MCP server so Claude Desktop, Cursor, and any MCP client can call it as a tool.
Deterministic — same input + same policy ⇒ same verdict.

Install

Run directly with npx (no global install):

Or add it to your MCP client config.

Claude Desktop

Add to claude_desktop_config.json:

json

{  "mcpServers": {    "paystage-preflight": {      "command": "npx",      "args": ["-y", "@paystage/preflight"],      "env": {        "PAYSTAGE_POLICY_PATH": "/absolute/path/to/policy.json"      }    }  }}

{  "mcpServers": {    "paystage-preflight": {      "command": "npx",      "args": ["-y", "@paystage/preflight"],      "env": {        "PAYSTAGE_POLICY_PATH": "/absolute/path/to/policy.json"      }    }  }}

Cursor

Add to .cursor/mcp.json:

json

{  "mcpServers": {    "paystage-preflight": {      "command": "npx",      "args": ["-y", "@paystage/preflight"],      "env": {        "PAYSTAGE_POLICY_PATH": "/absolute/path/to/policy.json"      }    }  }}

{  "mcpServers": {    "paystage-preflight": {      "command": "npx",      "args": ["-y", "@paystage/preflight"],      "env": {        "PAYSTAGE_POLICY_PATH": "/absolute/path/to/policy.json"      }    }  }}

Example `policy.json`

json

{  "version": 1,  "name": "standard",  "allowed_networks": ["eip155:8453", "eip155:84532"],  "allowed_assets": [    "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",    "0x036CbD53842c5426634e7929541eC2318f3dCF7e"  ],  "allowed_pay_to": ["0x209693Bc6afc0C5328bA36FaF03C514EF312287C"],  "max_amount_per_call": "1.00",  "max_amount_per_session": "10.00",  "require_human_above": "0.50",  "max_timeout_seconds": 300,  "default_verdict": "review"}

{  "version": 1,  "name": "standard",  "allowed_networks": ["eip155:8453", "eip155:84532"],  "allowed_assets": [    "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",    "0x036CbD53842c5426634e7929541eC2318f3dCF7e"  ],  "allowed_pay_to": ["0x209693Bc6afc0C5328bA36FaF03C514EF312287C"],  "max_amount_per_call": "1.00",  "max_amount_per_session": "10.00",  "require_human_above": "0.50",  "max_timeout_seconds": 300,  "default_verdict": "review"}

Amounts are human-readable USDC (e.g. "0.50" = 0.50 USDC). Networks use CAIP-2 identifiers.

Verdicts

Verdict	Meaning
`pay`	Within policy — safe to proceed automatically.
`review`	Allowed but above a human threshold — ask a human before paying.
`do_not_pay`	Violates policy (network, asset, payTo, amount, timeout, or malformed).

Supply chain and access

Socket.dev scores this package on what it can do, not what it does with it, so the flags it raises are worth explaining rather than removing:

Flag	Why it is there
Filesystem access	Reads the policy JSON you point it at (`policy_path` / `PAYSTAGE_POLICY_PATH`). Nothing is written.
Environment variable access	`PAYSTAGE_POLICY_PATH` only (and `PAYSTAGE_RPC_URL` via `auth-watch`).
Network access, URL strings	None in this package. The RPC endpoints you may see in the tree belong to `@paystage/auth-watch`.

No shell, no eval, no telemetry, no key custody. The full table is in SECURITY.md; the deny list is published with a citation per entry in KNOWN_DRAINERS.md.