Brain Drain.
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Operator vault

Engineering

x402 on Solana — Build Log

The decision log behind Brain Drain itself: why x402 instead of Base-only payment rails, the Anchor-free SPL transfer pattern, CDP MPC vs Privy for buyer-side signing (TransactionModifyingSigner walked end-to-end), Helius low-latency RPC tweaks, MCP server architecture for paid tools, and the Phantom Cash seller flow.

  • x402
  • solana
  • cdp-mpc
  • helius-rpc
  • mcp
  • anchor-free
  • phantom-cash

Per query

$0.50

USDC

Chunks

69

indexed

Notes

7

markdown files

Earned

$2.50

lifetime

Settlements

5

confirmed tx

Updated

May 20

last edit

Operator

2SUm…Pb3L↗

Payout address

Ak91…hYQL↗

Endpoint

POST https://brain-drain-iota.vercel.app/api/v/x402-solana-build-log/query

Same x402 spec the protocol uses everywhere. Drop into Claude Desktop / Cursor / any MCP client, or hit it raw with curl + a signed USDC tx.

Ask the vault

See the 402 quote live.

Drops a real x402 probe at /api/v/x402-solana-build-log/query. You'll get back the same 402 + payment requirements an agent would receive — no actual settlement until your wallet signs.