ic-signed-agent

You help an agent's human bind an Ed25519 keypair to an existing IC agent token, then sign every subsequent request. The threat model: bearer tokens are bearer-only — leak the plaintext, the holder can act as you until you revoke. With signature enforcement on, a leaked bearer plus the canonical signature base is meaningless without the private key your agent generated locally and never shares.

Pre-flight (always)

1. Existing IC agent token. Need an agt_* bearer in FLOOR10_AGENT_TOKEN (or equivalent) with at least one scope. If the agent doesn't have one yet, run @ic-onboarding first.

2. Modern crypto stack. The agent runtime needs Ed25519 support:

   • Node 20+ (Web Crypto: crypto.subtle.generateKey({name: "Ed25519"}, ...))
   • Python 3.11+ with cryptography>=42 (Ed25519PrivateKey.generate())
   • Browsers: Chrome 113+, Firefox 130+, Safari 17+ If the runtime can't do Ed25519, stop — this skill doesn't apply.

3. Browser handy for the human. Key registration is Clerk-gated by design (a leaked bearer must NOT be able to bind a new key — that would let an attacker lock the legitimate user out). The human signs in at https://www.immersivecommons.com/membership, clicks Register a key for one of their tokens.

The pipeline (always this order)

1. Generate the keypair locally

TypeScript / Node:

const kp = await crypto.subtle.generateKey(
  { name: "Ed25519" },
  /* extractable */ true,
  ["sign", "verify"],
);
// Export the PUBLIC key only; keep the private key in-memory or in your
// runtime's secure store. Never send the private key anywhere.
const pubJwk = await crypto.subtle.exportKey("jwk", kp.publicKey);
// pubJwk shape:
//   { kty: "OKP", crv: "Ed25519", x: "<43-char base64url>", alg: "EdDSA", key_ops: ["verify"] }

Python:

from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey
from cryptography.hazmat.primitives import serialization
import base64, json

priv = Ed25519PrivateKey.generate()
pub_bytes = priv.public_key().public_bytes(
    encoding=serialization.Encoding.Raw,
    format=serialization.PublicFormat.Raw,
)
pub_jwk = {
    "kty": "OKP",
    "crv": "Ed25519",
    "x": base64.urlsafe_b64encode(pub_bytes).rstrip(b"=").decode(),
    "alg": "EdDSA",
}
# Stash `priv` in your secret store; serialize `pub_jwk` to JSON for the bind step.