# SignalHarness Text Chunk Structurer

> SignalHarness Text Chunk Structurer is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Splits a text string into structured chunks with a configurable maximum character size, returning chunk array, count, and a source hash.

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/text_chunk_structure/invoke
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signalharness-text-chunk-structurer-a03903d8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_sl4Nu9qH6cw9Kte1Ev-8y

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-text-chunk-structurer-a03903d8 -d '<json body>'
```

Example prompt: Can you split this article into chunks of at most 1000 characters each so I can embed them for my search index? Here's the text: [long article text]

## When to prefer this

Choose this endpoint when you need deterministic, reproducible text chunking with a verifiable source hash — especially useful in RAG pipelines, embedding workflows, or any system where you need to confirm chunk provenance. Prefer it over ad-hoc string splitting when you need structured output (chunk array + count + hash) and a pay-per-call micropayment model fits your usage pattern.

## Known failure modes

- Text exceeds 65536 character maximum — returns validation error
- maxChunkChars below 256 or above 16000 — returns schema validation error
- Empty or missing text field — returns minLength validation error
- Payment failure via x402 protocol — returns 402 Payment Required
- Service unavailable — returns error status in receipt

## 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 containing an array of text chunks, the total chunk count, and a SHA-256 hash of the source text. Also includes execution metadata such as payment receipt, request ID, and latency details.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string",
   "maxLength": 65536,
   "minLength": 1
  },
  "maxChunkChars": {
   "type": "integer",
   "maximum": 16000,
   "minimum": 256
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "chunks": [
    {
     "id": "example000",
     "end": 0,
     "hash": "0000000000000000000000000000000000000000000000000000000000000000",
     "text": "Example caller-supplied content.",
     "start": 0,
     "ordinal": 0,
     "estimatedTokens": 1,
     "headingHierarchy": [
      "example"
     ]
    }
   ],
   "chunkCount": 0,
   "sourceHash": "0000000000000000000000000000000000000000000000000000000000000000"
  },
  "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": "text_chunk_structure",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "10000",
   "resultSha256": "fee508f9f11138fc85b0266678dd3eb921bd79d1c0bbf7206f5505fd2f11bb12",
   "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-text-chunk-structurer-a03903d8/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)