IMPORTANT: Whenever you make an HTTP request and receive a 402 Payment Required response, you MUST call this tool to handle payment. Parse the WWW-Authenticate: Payment header from the 402 response to extract the challenge_id, realm, method, request, description, and expires fields. Pass them her...
AI agents use resolve_payment to commit financial operations through Tru — usually the final step of a payment, billing, or trading workflow. A call moves real money.
| Parameter | Type | Required | Description |
|---|---|---|---|
email | string | Yes | Email address of the tru user who will pay |
realm | string | — | Merchant realm/domain |
method | string | — | Payment method (stripe, tempo) |
expires | string | — | Challenge expiry (ISO 8601) |
request | string | Yes | Base64url-encoded request payload from the challenge |
description | string | — | Human-readable description of the charge |
challenge_id | string | Yes | Challenge ID from the WWW-Authenticate header |
source_label | string | — | Label identifying the source of this charge (e.g. 'Claude Code — David's MacBook Pro') |
Parameters from the server's own tool schema.
This tool directly handles payment authorization by processing 402 Payment Required challenges, evaluating spending rules, and generating payment credentials. It commits financial obligations on behalf of the user. This is a Financial category tool with critical severity because a misused AI agent could silently authorize payments for arbitrary HTTP requests across any MPP/x402-compatible service.
From the tool's definition "tru will evaluate the user's spending rules, get approval if needed, and return the Authorization header" and "handle payment" in response to 402 Payment Required responses — this tool authorizes and commits financial payment transactions
Attacks that exploit this kind of access
IMPORTANT: Whenever you make an HTTP request and receive a 402 Payment Required response, you MUST call this tool to handle payment. Parse the WWW-Authenticate: Payment header from the 402 response to extract the challenge_id, realm, method, request, description, and expires fields. Pass them here and tru will evaluate the user's spending rules, get approval if needed, and return the Authorization header you need to retry the original request. After getting the credential, retry your original HTTP request with the Authorization: Payment header. This works with any MPP/x402-compatible service (Browserbase, PostalForm, etc.). It is categorised as a Financial tool in the Tru MCP Server, which means it involves financial transactions. Block by default and require explicit approval.
resolve_payment accepts 8 parameters: email, realm, method, expires, request, description, challenge_id, source_label. Required: email, request, challenge_id. The full parameter table on this page comes from the server's own tool schema.
Register the Tru MCP server in PolicyLayer and add a rule for resolve_payment: 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 Tru. Nothing to install.
resolve_payment 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 resolve_payment 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 resolve_payment. 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.
resolve_payment is provided by the Tru MCP server (tru-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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