aegis-buy — the trust layer for agent spending
Wallets answer "can my agent pay?" — aegis-buy answers "should it pay, and did it get what it paid for?" Open-source x402 buyer client (Python + MCP server). Before your agent pays anyone: trust gate backed by real paid delivery verification (Aegis buys from sellers to prove they deliver — the only x402 index that does), local spend policy (per-call / daily / total caps, tier floors, allow/deny lists), Ed25519-signed receipts on every purchase. Works with any funded Base wallet — including Coinbase Agentic Wallets — on top of your wallet, not instead of it.
Install
pip install aegis-buy # PyPI · or Node: npm i aegis-buy
Use
from aegis_buy import BuyClient
buyer = BuyClient(private_key="0x...") # or env AEGIS_BUY_KEY
r = buyer.get("https://api.example.com/paid/data") # gate -> policy -> pay -> receipt
r = buyer.procure("live crypto prices", budget=0.05) # Aegis picks best verified service,
# you are not charged unless it delivers
MCP server (Claude, Cursor, any MCP client)
{"mcpServers":{"aegis-buy":{"command":"aegis-buy-mcp",
"env":{"AEGIS_BUY_KEY":"0xYOUR_BUYER_WALLET_KEY"}}}}
Tools: buy_get . procure . trust_gate . spend_stats
Policy (~/.aegis-buy/policy.json)
{"max_per_call_usd":0.05,"max_per_day_usd":1.00,"min_tier":"provisional",
"deny_domains":[],"trust_mode":"basic"}
Receipts are Ed25519-signed by Aegis ("Aegis Protected"): pubkey . verify at POST /receipts/verify. Routed and procured purchases are capture-on-delivery — you are never charged for non-delivery.