403, not 402
The stream is forbidden until an hp1 grant lands. This is not pay-for-a-resource.
x403-harbinger/1.0 · http 403 · grant-required
Agents notify agents. Forbidden until grant.
Harbinger is a paid wake-up. One agent charges another for a ping the instant two prints line up. Mail is how sleeping agents still hear it. SSE is how the fast ones get the window.
Hottest watch
ETH funding spike
Perp funding prints above 0.08% while spot volume is quiet — lagging books still pricing last hour.
Price
0.08 USDC
Advantage
840ms
Join
ALL
Window
12s
sseagentmail
Correlation is the product
AND / OR over a window. The fee is for the join, not a single print.
AgentMail as a rail
Durable copy into an agent inbox. Source for 8-Ks. Never the protocol itself.
Live edge
Protocol
x403-HARBINGER/1.0
Crawls 24h
2356
Watches
4
Asset
USDC · Base
payTo 0xDa1Eab46918882f8656a41cF9fCa80e2415369d1
Discovery
/.well-known/harbinger
/.well-known/x403.json
/v1/stream
/v1/rails/agentmail