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Agent Identity

Okta for AI Agents, Cryptographic Identity

Every AI agent is assigned an Ed25519 cryptographic identity, a verifiable credential that defines what the agent is, what it's authorised to do, and under what conditions. The control plane verifies identity on every action before any policy evaluation. Replay protection is enforced via Redis-backed nonce deduplication across all workers.

Architecture: Ed25519 keypairs → W3C DIDs → Signed assertions → Redis replay guard → Permission boundaries → Credential lifecycle → Vault-bound proofs

Key Concepts

Concept Description
Ed25519 Keypair Every agent gets a public/private key. Private key returned once at registration, never stored server-side.
DID W3C-aligned did:xybern:{workspace}:{agent} identifier.
Signed Assertion JSON payload signed by agent's private key, verified by control plane in < 1 ms.
Permission Boundary Scopes, resource rules, temporal windows, delegation controls, rate limits.
Nonce + Timestamp Replay protection: each assertion must have a unique nonce and timestamp within 5 minutes. Nonces are deduplicated in Redis across all API workers. 
from xybern import Xybern, AgentCredential

client = Xybern(api_key="xb_your_key")

# Generates Ed25519 keypair, registers agent, issues credential — one call
cred = client.agents.register(
    name="Trading Agent Alpha",
    framework="langchain",
    capabilities=["execute_trade", "query_portfolio"],
)
cred.save("./trading_agent.cred")  # chmod 600, private key never leaves your server
print(cred.did)                    # did:xybern:{workspace}:agent_abc123
print(cred.key_fingerprint)        # SHA-256 hex fingerprint

Register Agent (raw API)

resp = requests.post(f"{BASE}/enforce/agents", headers=HEADERS, json={
    "name": "Trading Agent Alpha",
    "framework": "langchain",
    "scopes": ["trade:write", "db:read"],
    "permission_boundary": {
        "resource_rules": [{"action_types": ["execute_trade"], "max_amount": 50000}],
        "temporal": {"allowed_hours": {"start": 9, "end": 17}},
        "rate_limit": {"max_actions": 100, "window_minutes": 60}
    }
})
cred = resp.json()["credential"]
private_key = cred["private_key"]  # SAVE THIS — shown only once
did = cred["did"]                   # did:xybern:ws1:agent_abc123

Intercept with Identity (SDK, auto-signing)

# SDK signs every assertion automatically — no crypto code needed
result = client.agents.intercept(
    action_type="execute_trade",
    action_content="Buy 100 AAPL at market",
    credential="./trading_agent.cred",   # or AgentCredential object
    metadata={"ticker": "AAPL", "notional_usd": 19000},
)
# response includes identity_verified=True when signature checks pass
print(result.identity_verified)  # True

Intercept with Identity (raw API)

from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey
from base64 import b64encode, b64decode
import json, uuid

nonce = uuid.uuid4().hex
payload = {"agent_id": "agent_abc", "action": "execute_trade",
           "nonce": nonce, "timestamp": "2026-01-25T12:00:00Z"}
canonical = json.dumps(payload, sort_keys=True, separators=(",", ":")).encode()
pk = Ed25519PrivateKey.from_private_bytes(b64decode(PRIVATE_KEY))
sig = b64encode(pk.sign(canonical)).decode()

resp = requests.post(f"{BASE}/enforce/intercept", headers=HEADERS, json={
    "action_type": "execute_trade",
    "agent_id": "agent_abc",
    "signed_assertion": payload,
    "assertion_signature": sig
})
# → response: {"identity_verified": true, "identity": {"did": "...", "fingerprint": "..."}}