El Tucu: a 4-servo robot arm that AI agents can rent by the minute

Franco built El Tucu, a small desk arm with an ESP32 and four SG90 micro servos, as the first robot on Rent a Shell. The idea is that an agent which only lives in software can rent a robot body, send it a program, use it for the paid time and hand it back. In the demo, Codex rents the arm, pays with x402 and makes it wave.

Agents find the gateway through its llms.txt or MCP and pay per block with x402. People can rent too by scanning a Solana Pay QR, and that payment sits in an escrow program until the session ends. The README's test case is robotics QA: an agent pays for a block, runs a motion sequence, checks whether each joint reached its target and returns a report.

The README is upfront about what's real today: one shell, El Tucu, running on Solana devnet, with mainnet and the wider marketplace still on the roadmap. The builder's own post says the arm may be offline when you visit.