# x402-secure Agent Payment Evaluation

> x402-secure Agent Payment Evaluation is a paid API for AI agents from x402-secure-api.t54.ai, paid per call via x402, $0.0001/call, status unknown (last checked 2026-09-14).

Evaluates an agent's pending payment plan by analyzing its execution trace, returning a risk decision (allow/deny/challenge) with confidence score and risk level

## Facts

- Endpoint: POST https://x402-secure-api.t54.ai/x402/tools/evaluate_agent_payment
- Price: $0.0001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-secure-agent-payment-evaluation-2fc4cd04
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_64h7DyRFefTWvHETwWoL9

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability x402-secure-agent-payment-evaluation-2fc4cd04 -d '<json body>'
```

Example prompt: Can you evaluate whether agent_123 at wallet address 0xABC...123 should be allowed to make this payment? Here's the full execution trace showing the task it completed and all the events it triggered — I need a risk decision with confidence score before I approve anything.

## When to prefer this

Use this endpoint when an AI agent needs a security gate before executing a blockchain payment — specifically when you have a full agent execution trace and need a structured allow/deny/challenge decision with risk scoring. Prefer this over generic fraud checks when working within the x402 payment protocol ecosystem on Base L2 or similar chains.

## Known failure modes

- Missing required fields (agent_id, wallet_address, agent_trace, authorization) returns 400 validation error
- Invalid or expired authorization token returns 401 unauthorized
- Malformed agent_trace object (missing task, events, or completed_at) may result in low-confidence or unknown risk decision
- Network timeout if trace payload is excessively large
- Service unavailability returns 503 with health check recommended

## How this service works

Evaluate an agent's pending payment plan by submitting agent_id, wallet_address, and a full agent_trace. Returns a normalized summary acknowledging the payload. Price: $0.0001 USDC

## Output

Returns a structured decision object containing: a decision field (allow/deny/challenge), risk_level (low/medium/high/critical/unknown), confidence_score, list of reasons and warnings, trace_id, session_id, decision_id, ttl_seconds indicating how long the decision is valid, and a flag indicating whether a mandate was used.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "agent_id",
  "agent_trace",
  "authorization",
  "wallet_address"
 ],
 "properties": {
  "agent_id": {
   "type": "string",
   "description": "Unique identifier of the agent performing the action (e.g., 'agent_123')."
  },
  "agent_trace": {
   "type": "object",
   "description": "Agent execution trace object. Include 'task' (string), 'events' (array of event objects with fields like 'ts', 'type', 'role'/'name', 'content'/'arguments'/'result'), and 'completed_at' (ISO timestamp). This field is nested; provide the full trace payload for evaluation."
  },
  "authorization": {
   "type": "string",
   "description": "Upstream Authorization token."
  },
  "wallet_address": {
   "type": "string",
   "description": "User or agent wallet address on chain (e.g., Base L2 address)."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "extra": {
  "type": "object",
  "properties": {
   "mode": "string",
   "final_tier": "string",
   "confidence_score": "number",
   "processing_time_ms": "number"
  }
 },
 "reasons": "array",
 "decision": {
  "enum": [
   "allow",
   "deny",
   "challenge"
  ],
  "type": "string"
 },
 "trace_id": "string",
 "warnings": "array",
 "risk_level": {
  "enum": [
   "low",
   "medium",
   "high",
   "critical",
   "unknown"
  ],
  "type": "string"
 },
 "session_id": "string",
 "decision_id": "string",
 "ttl_seconds": "number",
 "used_mandate": "boolean"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-secure-agent-payment-evaluation-2fc4cd04/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-secure-api.t54.ai](https://www.zero.xyz/host/x402-secure-api.t54.ai/llms.txt)