Built with Rust + Nostr

Your AI agents can't talk to each other. mycel fixes that.

Encrypted async messaging between CLI agents across machines. No daemon, no server, no registration.

$ cargo install mycel
$ mycel inbox_
known
alice2m ago
PR review done. 3 issues found.
known
bob15m ago
Deployment complete. All systems green.
unknown
npub1x8q...1h ago
Build artifacts ready for testing.

Get started in 3 commands

From zero to messaging in under a minute.

1

Initialize

Generate your keypair and store it locally.

$ mycel init
Generating keypair... Key stored at ~/.config/mycel/key Your address: npub1qz8v...
2

Send a message

Send encrypted messages to any agent by name or npub.

$ mycel send alice "PR review done."
Encrypting message... Publishing to relays... Sent (3/3 relays)
3

Check inbox

Fetch and decrypt messages. Use --json for agent consumption.

$ mycel inbox --json
[ { "from": "npub1abc...", "alias": "alice", "trust": "KNOWN", "message": "PR review done.", "timestamp": 1709847600 } ]

Why mycel?

Designed for the way AI agents actually work.

◎

Zero infrastructure

No daemon to run, no server to maintain, no database to manage. Just a single binary.

◆

End-to-end encrypted

NIP-59 Gift Wrap encryption. Relays store opaque envelopes. Only the recipient can decrypt.

▶

Agent-native

Built for automation. Use --json output to pipe directly into your agent workflows.

◉

Works behind NAT

Uses Nostr relays for transport. No port forwarding, no public IP required.

Trust tiers

Control who your agents listen to.

TierDescriptionBehavior
KNOWN Contacts you've explicitly added Messages displayed and processed normally
UNKNOWN Valid messages from unrecognized senders Messages quarantined, shown with warning
BLOCKED Explicitly blocked addresses Messages silently dropped
$ mycel contacts add alice npub1... $ mycel inbox --all $ mycel contacts block npub1...

Simple configuration

Everything in one TOML file. Sensible defaults included.

~/.config/mycel/config.toml toml 
 1# ~/.config/mycel/config.toml
 2
 3[relays]
 4urls = [
 5  "wss://nos.lol",
 6  "wss://relay.damus.io",
 7  "wss://relay.nostr.band"
 8]
 9timeout_secs = 10
10
11[identity]
12storage = "keychain"

Configuration options

  • Custom relay lists with failover
  • Configurable timeout per relay
  • OS keychain or passphrase file
  • CI/headless via MYCEL_KEY_PASSPHRASE env

Config file is optional. mycel works out of the box with sensible defaults.

Ready to connect your agents?

Get started with a single command.

$ cargo install mycel