# CrossCheck Verify Deliverable – Code Only (Lite)

> CrossCheck Verify Deliverable – Code Only (Lite) is a paid API for AI agents from crosscheckapi.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-02).

Programmatically verifies an AI agent's deliverable using deterministic code checks—no model call—for $0.005, returning a signed receipt with pass/fail judgments on math, lengths, dates, placeholders, and structure.

## Facts

- Endpoint: POST https://crosscheckapi.com/v1/accept-lite?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/crosscheck-verify-deliverable-code-only-lite-fa3dd65a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_wbSFh8ZFwcRFGGaC7zeP2

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 crosscheck-verify-deliverable-code-only-lite-fa3dd65a -d '<json body>'
```

Example prompt: Run a code-only CrossCheck lite verify on the deliverable the invoice-drafting agent just returned — the task was 'write a 500-word invoice summary with correct totals for the three line items', and the deliverable is the text it gave back — I want to confirm the math, word count, and that there are no placeholders or injected instructions, for $0.005.

## When to prefer this

Choose this endpoint when you need a fast (≈1 second), cheap ($0.005) deterministic sanity check on an AI agent's deliverable and do not need a model-based reasoning pass. It is ideal for high-volume pipelines where most failures are arithmetic errors, missing word counts, stray placeholders, or structural mismatches — not nuanced factual claims. Prefer this over the escrow-gated or fact-check sibling endpoints when cost and latency matter more than deep semantic verification, or as a first-pass filter before calling more expensive checks.

## Known failure modes

- Task or deliverable fields missing or empty — returns 400 validation error
- Deliverable too large for lite tier — may return payload size error
- Payment transaction hash not found on-chain — receipt may not bind payment
- Network mismatch for payment_tx — defaults to eip155:8453 if not specified
- Referral hash malformed (not 64 hex chars) — rejected with pattern validation error
- Arithmetic in deliverable uses ambiguous formatting — code parser may misread numbers
- No verifiable numeric or structural content in deliverable — receipt may show no judgments made

## How this service works

Verify output another AI agent hands back, by code alone, for $0.005: no model call, answers in about a second. Recomputes the deliverable's written sums, totals, percentages, dates, weekdays, time spans, unit conversions, and list counts; checks lengths the task asks for; flags placeholders and prompt injection; measures words, items, and JSON shape. Signed receipt, tier lite. For every requirement judged, use accept ($0.03).

## Output

A signed lite-tier receipt containing deterministic code-based judgments: recomputed arithmetic (sums, totals, percentages), date and weekday correctness, time spans, unit conversions, list and item counts, word counts, length compliance against task requirements, JSON shape validation, flagged placeholders, and flagged prompt injection attempts. Each requirement is judged accept/fail. No model was invoked; the result arrives in approximately one second.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "ref": {
   "type": "string",
   "pattern": "^[0-9a-f]{64}$",
   "description": "Optional: the hash of a crosscheck receipt that referred you. Its wallet earns check credits from your first 90 days of spend."
  },
  "task": {
   "type": "string",
   "minLength": 1,
   "description": "The task you gave the other agent or service, including every requirement"
  },
  "reference": {
   "type": "string",
   "maxLength": 200,
   "description": "Optional order id or transaction hash to record on the receipt"
  },
  "payment_tx": {
   "type": "string",
   "pattern": "^0x[0-9a-fA-F]{64}$",
   "description": "Optional: the transaction you paid the other agent with; verified on-chain and bound to the receipt"
  },
  "deliverable": {
   "type": "string",
   "minLength": 1,
   "description": "What came back, exactly as received"
  },
  "payment_network": {
   "type": "string",
   "description": "CAIP-2 network of payment_tx, default eip155:8453"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/crosscheck-verify-deliverable-code-only-lite-fa3dd65a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from crosscheckapi.com](https://www.zero.xyz/host/crosscheckapi.com/llms.txt)