# Delx Token Echo 1

> Delx Token Echo 1 is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).

Echoes input text back with its character length, primarily for verifying that x402 pay-to-deliver payment wiring is functioning correctly.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/token-echo-1
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-token-echo-1-29cfcb66
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Twh0Gt-y1dHBCYNnr4_XM

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 delx-token-echo-1-29cfcb66 -d '<json body>'
```

Example prompt: Echo the text 'hello world' back to me using the Delx token echo probe — I just want to verify the x402 payment pipeline is wired up correctly.

## When to prefer this

Choose this endpoint when you need the cheapest and simplest possible probe to confirm that an x402 micropayment channel on Base is correctly wired — before committing to more expensive or complex paid endpoints. It is ideal for CI smoke tests, new wallet validation, and integration bootstrapping where the payload itself is irrelevant and only the pay-to-deliver round trip matters.

## Known failure modes

- Payment not received — x402 handshake fails, no response delivered
- Malformed input — missing or non-string text field returns a validation error
- Insufficient USDC balance — payment of $0.001 cannot be completed
- Network timeout during payment settlement on Base
- Empty text field submitted — length returns 0 but echo may still succeed

## How this service works

Echo text with length (probe channel 1). Call when you verify x402 pay→deliver wiring with a trivial payload. Returns echo text, length, echo=1 for $0.001 USDC via x402 on Base. No network, no keys, no retention; first-party local JSON only. Results are advisory; the caller owns budgets, auth, and production controls.

## Output

Returns a JSON object containing the original echoed text, its character length, and an echo flag set to 1, confirming that the x402 pay-to-deliver pipeline processed the request successfully. No external network calls are made and no data is retained.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string",
   "description": "Input field: text."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "echo": 1,
  "text": "ping-delx-1",
  "length": 11,
  "schema": "delx/util-token-echo-1/v1"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-token-echo-1-29cfcb66/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)