Compute

Jack Cloud runs agent code in sandboxed V8 isolates. No account, no API key — agents pay per execution with USDC stablecoins via MPP.

Endpoint

POST https://mcp.getjack.org/execute

Request

{
  "code": "export function run(input) { return { sum: input.a + input.b }; }",
  "input": { "a": 2, "b": 3 }
}

Code must export a run(input) function. Async functions work. Returns any JSON-serializable value.

Response

{
  "result": { "sum": 5 },
  "duration_ms": 12,
  "limits": { "cpu_ms_limit": 50 }
}

Limits

Payment flow

1. Agent sends POST /execute with code
2. Server returns HTTP 402 + WWW-Authenticate header (MPP challenge)
3. Agent's payment client (tempo, mppx) pays $0.01 USDC on Tempo chain
4. Request retried with payment credential
5. Code executes, result returned with payment receipt

Try it

curl -L https://tempo.xyz/install | bash
tempo add request
tempo wallet login
 
tempo request -t -X POST \
  --json '{"code":"export function run(i) { return { sum: i.a + i.b } }","input":{"a":2,"b":3}}' \
  https://mcp.getjack.org/execute

Agent integration

Point your agent at https://docs.getjack.org/SKILL.md for auto-discovery:

claude "Read https://docs.getjack.org/SKILL.md and compute fibonacci(20) on Jack Cloud"

MCP transport

MCP clients (Claude Code, Cursor) can also use the JSON-RPC endpoint:

POST https://mcp.getjack.org/mcp/public

Payment challenges use MCP error code -32042 with the challenge in error.data.challenges[].