Why does it take 669 bytes to tell a computer there is a fire?

ECP encodes the core alert fields in 8 bytes. Fire, flood, security, IoT threshold, fleet beacon — same compact format.

UET (8 bytes) is the compact unsigned token. For cryptographic signing, use an Envelope (typically 42 bytes with HMAC). These values are live-measured in the CLI ProofCard tool. This page shows the canonical FIRE scenario for instant sharing. Clone the repository to verify independently, including the raw payloads via -- --show-payload.