# Tereno Transaction Intent Guard

> Tereno Transaction Intent Guard is a paid API for AI agents from tereno.xyz, paid per call via x402, $0.25/call, status unknown (last checked 2026-09-15).

Analyzes a blockchain transaction's intent and returns a decision-ready verdict (allow/block/warn) with risk assessment, simulation results, and allowance change detection

## Facts

- Endpoint: POST https://tereno.xyz/api/v1/capabilities/transaction.intent.guard/invoke
- Price: $0.25/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tereno-transaction-intent-guard-af29989b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2Nhe5nP9s7_9_1pYGtqbX

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 tereno-transaction-intent-guard-af29989b -d '<json body>'
```

Example prompt: Before I sign this transaction, run it through Tereno's intent guard — here's the calldata and contract address — and tell me the verdict, any risk flags, and whether any token allowances are changing.

## When to prefer this

Choose this endpoint when an AI agent needs a pre-signing security verdict for a Base blockchain transaction — especially in autonomous workflows where a human isn't reviewing every transaction. It is ideal for DeFi interactions, agent-to-agent payments, and any scenario where unexpected allowance grants, proxy contracts, or revert risks need to be caught before signing. Prefer this over generic simulation tools when you need structured risk verdicts and allowance-change detection in a single paid-per-call API.

## Known failure modes

- Invalid or malformed transaction calldata returns a validation error
- Unsupported chain or contract address returns a 400 error
- Simulation failure returns success:false with a revertReason
- Network congestion on Base may delay simulation results
- Insufficient USDC payment via x402 returns a 402 Payment Required error
- Unknown or unverified contract may return limited risk signals

## How this service works

The cooperation layer for autonomous agents on Base. Buy decision-ready verdicts, publish verified work and earn credits when the network reuses it through x402.

## Output

Returns a JSON object containing: a top-level verdict (allow/block/warn), detected intent (e.g. 'transfer'), array of risk flags, simulation results including success status and estimated gas, balance deltas, allowance changes, contract target metadata (proxy status, paused state, implementation changes), a validUntilBlock for cache freshness, plus pricing metadata and a receipt URL.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "to": {
   "type": "string",
   "pattern": "^0x[a-fA-F0-9]{40}$",
   "description": "Unsigned transaction target on Base."
  },
  "data": {
   "type": "string",
   "pattern": "^0x[a-fA-F0-9]*$",
   "maxLength": 262146,
   "description": "Unsigned calldata, up to 128 KiB."
  },
  "from": {
   "type": "string",
   "pattern": "^0x[a-fA-F0-9]{40}$",
   "description": "Unsigned transaction sender on Base."
  },
  "value": {
   "type": "string",
   "pattern": "^[0-9]+$",
   "description": "Native ETH value in wei."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "risks": [],
   "intent": "transfer",
   "target": {
    "proxy": false,
    "paused": null,
    "implementationChanged": false
   },
   "verdict": "allow",
   "simulation": {
    "success": true,
    "estimatedGas": "21000",
    "revertReason": null
   },
   "balanceDeltas": [],
   "validUntilBlock": 123456,
   "allowanceChanges": []
  },
  "pricing": {
   "currency": "USDC",
   "listPriceUsd": 0.005,
   "pricePaidUsd": 0.005,
   "creditAppliedUsd": 0,
   "actualCacheStatus": "miss",
   "quotedCacheStatus": "miss"
  },
  "verdict": "allow",
  "receiptUrl": "/api/v1/receipts/uuid",
  "capabilityId": "transaction.intent.guard",
  "invocationId": "uuid",
  "capabilityVersion": "1.0.0"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tereno-transaction-intent-guard-af29989b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from tereno.xyz](https://www.zero.xyz/host/tereno.xyz/llms.txt)