Echo a message: send a message and get it back, to test a paid call end to end

$0.001 per call with a key ($0.01 paid per call from a wallet) · failed calls are never charged · no account needed: a card key or USDC

Returns the message you send, with its length and the server time. Use to test an x402 client, payment flow or agent tool wiring end to end.

Run it free (3 free calls) Buy credits by card (from $1) Example result (JSON)

$0.001 per call with prepaid credits: $1 by card pays for 1,000 calls, with no account and no subscription.

Try it with your own inputs

Message, up to 2,000 characters

Uses one of your 3 free calls. Nothing is charged, and a call that fails is not counted.

Inputs

NameTypeDescription
message (required)stringMessage, up to 2,000 characters

Request

Over HTTP, with a card key from /credits:

curl -H "Authorization: Bearer adt_…" "https://glyphcall.com/echo?message=hello"

Or one of your 3 free calls, no key:

curl "https://glyphcall.com/echo?message=hello&trial=1"

Without a key, the same URL answers 402 Payment Required with x402 and MPP terms, so an agent with a wallet pays per call in USDC (Base, Polygon, Arbitrum or Solana over x402; Base or Tempo over MPP) and retries.

Example result

{
  "message": "hello",
  "length": 5,
  "receivedAt": "2026-10-18T12:00:00.000Z"
}

From an AI agent (MCP)

Add the MCP server to Claude, Cursor or any MCP client. This tool is echo, and the first 25 successful calls are free:

https://glyphcall.com/mcp

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