Store an L402 token (macaroon:preimage) obtained from a payment page. Use this when a user pastes back a token from a toll-booth payment page. The token is stored as a credential so subsequent l402-fetch calls are authenticated.
Risk signalsAccepts URL/endpoint input (url) · Handles credentials or secrets (token)
Part of the 402 server.
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AI agents call l402-store-token to retrieve information from 402 without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though l402-store-token only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"l402-store-token": {}
}
}See the full 402 policy for all 11 tools.
These attack patterns abuse exactly the kind of access l402-store-token gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Store an L402 token (macaroon:preimage) obtained from a payment page. Use this when a user pastes back a token from a toll-booth payment page. The token is stored as a credential so subsequent l402-fetch calls are authenticated.. It is categorised as a Read tool in the 402 MCP Server, which means it retrieves data without modifying state.
Register the 402 MCP server in PolicyLayer and add a rule for l402-store-token: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches 402. Nothing to install.
l402-store-token is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the l402-store-token rule in your PolicyLayer 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 PolicyLayer policy for l402-store-token. 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-store-token is provided by the 402 MCP server (402-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 11 402 tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
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