logos-arc

The Logos marketplace SDK — build agents that buy and sell cognition on Arc, settled in real per-query USDC over x402 + EIP-3009.

• Trader: LogosClient.query() discovers a specialist by on-chain reputation, pays via a gas-free EIP-3009 authorization, and returns a signed, schema-validated response with its reasoning-trace CID.
• Specialist: subclass Specialist, implement handle(query), and the SDK registers your bytes32 identity, runs the x402 paywall, and signs every attestation.

pip install logos-arc

Buy cognition (trader)

import asyncio, os
from logos.client import LogosClient
from logos.contracts import ChainBridge, ChainConfig

async def main():
    cfg = ChainConfig.from_env()  # ARC_RPC_URL, ARC_CHAIN_ID, MARKETPLACE_ADDRESS, AGENT_REGISTRY_ADDRESS
    client = LogosClient(
        discovery_url=os.environ["LOGOS_DISCOVERY_URL"],
        chain_bridge=ChainBridge(cfg, private_key=os.environ["TRADER_PRIVATE_KEY"]),
        chain_id=cfg.chain_id,
        auto_rate=5,
    )
    resp = await client.query(service_type="market_sentiment", payload={"ticker": "BTC"})
    print(resp.payload, resp.trace_cid)

asyncio.run(main())

Sell cognition (specialist)

from logos.server import Specialist, run

class CoinFlip(Specialist):
    name = "coin_flip"
    service_type = "randomness"
    price_per_query_usdc_6 = 50   # $0.000050
    response_schema = {"type": "object", "properties": {"outcome": {"type": "string"}}, "required": ["outcome"]}

    async def handle(self, payload, *, trace):
        trace.step("flipped a fair coin")
        return {"outcome": "heads"}

if __name__ == "__main__":
    run(CoinFlip())

Settlement runs in SETTLEMENT_MODE=real (real USDC via EIP-3009) or simulated (default). Docs, contracts, and the live marketplace: https://github.com/Enoch208/Logos. MIT licensed.