# SignalHarness Agent Plan Completion Check

> SignalHarness Agent Plan Completion Check is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Analyzes a caller-supplied plan or task description as JSON and returns a completion status assessment with warnings and evidence scope

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/agent_plan_completion_check/invoke
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signalharness-agent-plan-completion-check-401a8e66
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_bn1zg8t1p9T0ayW5VioeS

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 signalharness-agent-plan-completion-check-401a8e66 -d '<json body>'
```

Example prompt: Check whether this agent plan is complete — here's the JSON describing the tasks and their outcomes: {"steps":[{"id":1,"task":"fetch data","status":"done"},{"id":2,"task":"analyze results","status":"done"}]}.

## When to prefer this

Choose this endpoint when an AI agent needs a lightweight, pay-per-call ($0.01 USDC) programmatic check on whether a structured plan or workflow has reached completion. Ideal for agent orchestration pipelines that need a neutral third-party completion assessment before proceeding to downstream steps, triggering handoffs, or logging outcomes. Prefer this over building custom completion logic when you want a receipt-backed, auditable check with cryptographic result hashing.

## Known failure modes

- Malformed or non-JSON request_json input may cause parsing failures
- Input exceeding 65536 characters will be rejected
- Ambiguous or incomplete plan data may trigger generic warnings rather than specific analysis
- Payment failure via x402 protocol will prevent execution
- Result analysis is bounded by caller-supplied data quality — garbage in, garbage out

## How this service works

Explore 330 pay-per-call x402 API services and 27 agent-native digital products, with Base USDC pricing, secure Polar checkout, and free discovery.

## Output

Returns a JSON object with a 'status' field (e.g. 'succeeded'), an 'analysis_json' string containing the structured completion assessment, a list of 'warnings' (e.g. reminders to verify caller-supplied data), an 'evidence_scope' field indicating the data source, a cryptographic receipt with payment and execution metadata, and a 'replay' flag. The receipt includes network, asset, amounts, latency, and a SHA-256 hash of the result.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "request_json": {
   "type": "string",
   "maxLength": 65536,
   "minLength": 2
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "warnings": [
    "Verify the caller-supplied data before relying on this result."
   ],
   "service_id": "agent_plan_completion_check",
   "analysis_json": "{\"example\":\"schema-valid caller-supplied data\"}",
   "evidence_scope": "caller_supplied_data"
  },
  "status": "succeeded",
  "receipt": {
   "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
   "usage": [],
   "status": "succeeded",
   "network": "eip155:8453",
   "artifacts": [],
   "endedAtMs": 0,
   "latencyMs": 0,
   "paymentId": "example-payment",
   "receiptId": "example-receipt",
   "requestId": "example-request",
   "serviceId": "agent_plan_completion_check",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "10000",
   "resultSha256": "d4020ab342933fe0429e5f847d4012be71f1f64dfa6ce0b63151eb411d547d27",
   "serviceVersion": "1.0.0",
   "settlementReference": "0x0000000000000000000000000000000000000000000000000000000000000000"
  },
  "artifacts": [],
  "requestId": "example-request",
  "executionId": "example-execution"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/signalharness-agent-plan-completion-check-401a8e66/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from signalharness.ai](https://www.zero.xyz/host/signalharness.ai/llms.txt)