Confirm payment and store credentials. Call this after l402-fetch returns a 402 with a paymentHash — polls the payment server for settlement (up to 30s for human wallet), then stores the credential so the next l402-fetch succeeds. For human wallets, call this immediately after showing the payment...
Part of the 402 MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.
AI agents use l402-pay to initiate financial transactions through 402. Financial operations involve real money and are irreversible once processed. Intercept blocks financial tools by default, requiring explicit human approval with transaction-level limits to prevent unauthorised spending.
l402-pay moves real money. Without a policy, an autonomous agent could initiate transactions that drain accounts or exceed budgets. Intercept blocks financial tools by default, requiring human-in-the-loop approval with configurable spending limits per transaction and per time window.
Financial tools involve real money. Block by default and require explicit human approval before enabling.
tools:
l402-pay:
rules:
- action: deny
reason: "Requires human approval"See the full 402 policy for all 11 tools.
Agents calling financial-class tools like l402-pay have been implicated in these attack patterns. Read the full case and prevention policy for each:
Other tools in the Financial risk category across the catalogue. The same policy patterns (deny, require_approval) apply to each.
l402-pay is one of the critical-risk operations in 402. For the full severity-focused view — only the critical-risk tools with their recommended policies — see the breakdown for this server, or browse all critical-risk tools across every MCP server.
Confirm payment and store credentials. Call this after l402-fetch returns a 402 with a paymentHash — polls the payment server for settlement (up to 30s for human wallet), then stores the credential so the next l402-fetch succeeds. For human wallets, call this immediately after showing the payment URL to the user.. It is categorised as a Financial tool in the 402 MCP Server, which means it involves financial transactions. Block by default and require explicit approval.
Add a rule in your Intercept YAML policy under the tools section for l402-pay. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the 402 MCP server.
l402-pay is a Financial tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the l402-pay rule in your Intercept policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the Intercept policy for l402-pay. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
l402-pay is provided by the 402 MCP server (402-mcp). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Open source. One binary. Zero dependencies.
npx -y @policylayer/intercept