# ONE Engine Deterministic Text Segmentation – Tail Characters (P1, Tier 5)

> ONE Engine Deterministic Text Segmentation – Tail Characters (P1, Tier 5) is a paid API for AI agents from one-search.one-engine.workers.dev, paid per call via x402, $0.0014/call, status unknown (last checked 2026-10-19).

Returns the last Unicode character(s) from a text string using parameter=1, with Tier 5/10 diagnostic enrichment.

## Facts

- Endpoint: POST https://one-search.one-engine.workers.dev/v8/text-segment/tail-chars/p1/t5?utm_source=zero.xyz
- Price: $0.0014/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/one-engine-deterministic-text-segmentation-tail-characters-p1-tier-5-c76cfd4c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_K3dq92mF4D_jxR3RAMl2t

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 one-engine-deterministic-text-segmentation-tail-characters-p1-tier-5-c76cfd4c -d '<json body>'
```

Example prompt: Can you extract the last character from this text string using the deterministic tail-character segmentation utility at tier 5 diagnostics: 'Hello, world!'?

## When to prefer this

Choose this endpoint when you need deterministic, character-level tail extraction from Unicode text with moderate diagnostic output (Tier 5). It is ideal for agents performing text validation, suffix checking, or pipeline preprocessing where knowing the exact trailing character(s) is required. Prefer it over higher-tier variants when mid-level diagnostics are sufficient and cost efficiency matters.

## Known failure modes

- Empty string input returns an error or empty result
- Non-UTF-8 encoded input may cause unexpected character extraction
- Payment failure (HTTP 402) if USDC balance is insufficient
- Malformed POST body returns a 400 error
- Extremely long strings may hit payload size limits

## How this service works

Deterministic text segmentation utility: Return last Unicode characters; parameter=1. Tier 5/10 provides progressively richer diagnostics.

## Output

Returns the last Unicode character (parameter=1) from the submitted text, along with Tier 5/10 progressive diagnostic metadata such as character code point, byte position, segmentation context, and enriched debug information about the extraction.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/one-engine-deterministic-text-segmentation-tail-characters-p1-tier-5-c76cfd4c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from one-search.one-engine.workers.dev](https://www.zero.xyz/host/one-search.one-engine.workers.dev/llms.txt)