GET /api/v1/paid/echo — $0.01 per call

Use when an agent is checking that its x402 payment headers and query encoding survive a paid round trip. Returns The query parameters you sent, echoed back with a server timestamp. $0.01.

Price	$0.01 per call (10000 atomic USDC, scheme exact)
Category	utility
Rails	x402 · USDC on Base (eip155:8453) and Solana · MPP pathUSD on Tempo
Canonical URL	https://api.oblique.markets/api/v1/paid/echo

Try it

curl -i https://api.oblique.markets/api/v1/paid/echo
# → HTTP 402 with the exact payment requirements; pay, then retry with PAYMENT-SIGNATURE (x402) or Authorization: Payment (MPP)

Input schema

{
 "type": "object",
 "description": "Any query parameters; they are returned verbatim.",
 "properties": {},
 "additionalProperties": {
  "type": "string"
 }
}

Example output

{
 "echo": {
  "hello": "world",
  "n": "1"
 },
 "timestamp": "2026-09-12T00:08:59.286Z",
 "message": "This response was paid for via x402 protocol"
}

Clients

Worked TypeScript/Python clients and MCP configs: oblique-markets/oblique-examples · Agent Skills: oblique-markets/skills

Pay per call with x402 (USDC on Base or Solana) or MPP (pathUSD on Tempo). No accounts. Machine doors: /.well-known/x402.json · /openapi.json · /llms-full.txt · MCP · humans: remote.observer