Loopwall

What it does

Multi-agent chains can loop infinitely and burn budgets unnoticed. Loopwall is the spine of safe x402 orchestration: call /issue at chain start to mint a signed Job Envelope ($0.001) with origin, max_hops, and USD budget cap; then call /hop at each subsequent step ($0.0005) to validate against loop detection, hop-limit, and remaining budget. The envelope is cryptographically signed so any downstream agent can verify chain provenance without trusting the caller. Use as the orchestration backbone for any LLM-driven workflow that calls paid services.

When to use it

• Cap an LLM orchestrator at 10 paid x402 hops before manual review
• Detect a planning agent recursively calling itself before it drains budget
• Pass a signed budget envelope across agents in different organisations
• Audit trail of which agent in a chain consumed which fraction of the budget

Request schema

{
  "origin": "planner-agent-v1",
  "max_hops": 10,
  "budget_usd": 1
}

Response schema

{
  "envelope_id": "env_7ea9afac-c3d1-4b2e-9f3a-1234abcd5678",
  "origin": "planner-agent-v1",
  "max_hops": 10,
  "hops_remaining": 10,
  "budget_usd": 1,
  "budget_remaining_usd": 1,
  "signature": "0xabc...",
  "issued_at": "2026-05-15T12:00:00Z",
  "payment_hash": "0x..."
}

Code example — TypeScript via MCP

Install the MCP server once; all 22 services become tool calls.

// Configure @melis-ai/x402-tools-mcp in your MCP client
// Then call the tool:

const result = await mcpClient.callTool("loopwall", {
  "origin": "planner-agent-v1",
  "max_hops": 10,
  "budget_usd": 1
});

console.log(result);
// ["envelope_id","origin","max_hops","hops_remaining","budget_...

Code example — Python via direct HTTP

import requests

# x402 payment header must be set by your wallet client
# See x402.org for client libraries

headers = {
    "Content-Type": "application/json",
    "x-payment": "<signed-x402-payment-header>",
}

resp = requests.post(
    "https://loopwall.melis.ai/issue",
    json={
      "origin": "planner-agent-v1",
      "max_hops": 10,
      "budget_usd": 1
    },
    headers=headers,
)
print(resp.json())

Code example — curl with internal key bypass

For testing with an issued internal key (skips x402 payment flow):

curl -X POST https://loopwall.melis.ai/issue \
  -H "Content-Type: application/json" \
  -H "x-internal-key: YOUR_KEY" \
  -d '{"origin":"planner-agent-v1","max_hops":10,"budget_usd":1}'

How is this different from alternatives?

Related services

FAQ