Ed25519 Identity

Every entity on Zynd has an Ed25519 keypair. Ed25519 is fast, compact, and purpose-built for digital signatures.

Your public key deterministically generates your entity ID. This cryptographic commitment makes spoofing impossible.

ID Formats

Each entity type has a distinct prefix:

Entity Type	ID Format	Example
Agent	zns:<sha256(pubkey)[:16].hex()>	zns:8e92a6ed48e821f4
Service	zns:svc:<sha256(pubkey)[:16].hex()>	zns:svc:f34b12cd9a7e5c88
Developer	zns:dev:<sha256(pubkey)[:16].hex()>	zns:dev:a1c9e7f2b6d4e310

Signature and Key Formats

All signatures and public keys follow a consistent format:

Signature: ed25519:<base64_signature>
Public Key: ed25519:<base64_public_key>

Generate a Keypair

Using the Python SDK

from zyndai_agent.ed25519_identity import generate_keypair, save_keypair, load_keypair

kp = generate_keypair()
print(kp.agent_id)           # zns:8e92a6ed48e821f4...
print(kp.public_key_string)  # ed25519:<b64>

save_keypair(kp, "keypair.json")
kp = load_keypair("keypair.json")

Using the CLI

zynd keys create --name my-agent
zynd keys list
zynd keys show my-agent

Sign and Verify Messages

Use your private key to sign data. Others verify using your public key.

from zyndai_agent.ed25519_identity import sign, verify

signature = sign(kp.private_key, b"hello world")
# Returns: "ed25519:<base64>"

is_valid = verify(kp.public_key_b64, b"hello world", signature)

What Gets Signed

Your keypair proves ownership across the network:

• Agent Cards served at /.well-known/agent.json
• Registry registrations proving keypair ownership
• Heartbeat messages for liveness proof
• HD derivation proofs linking agents to developers
• Gossip announcements verified by origin registry

Keypair Resolution Priority

The SDK checks for your keypair in this order:

1. ZYND_AGENT_KEYPAIR_PATH environment variable
2. ZYND_AGENT_PRIVATE_KEY environment variable (base64-encoded)
3. agent_config.keypair_path configuration file
4. .agent/config.json legacy location

TIP

Set ZYND_AGENT_KEYPAIR_PATH in your shell profile for automatic agent startup.