Tempo is shipping the T3 (Wagner) hard fork in v1.6.0 — a mandatory, breaking network upgrade introducing enhanced access key permissions, signature verification precompiles, virtual forwarding addresses, and consensus improvements, with testnet activation on Apr 21 and mainnet on Apr 27.

# -------------------------------------------------------
# Exploring TIP-1011 Scoped Access Keys & TIP-1020 Signature Precompile
# Tested against Tempo T3 (Wagner) on Moderato testnet
# -------------------------------------------------------

# Step 1: Upgrade your node to v1.6.0
# If you're running a validator or RPC node, this is mandatory.
# Download the release and verify the binary hash before swapping.
#
# $ tempo version
# > tempo v1.6.0-wagner
#
# IMPORTANT: Remove any --consensus.enable-subblocks flag from your
# startup scripts. This flag no longer exists and will cause a boot error.
# ENR fork ID enforcement is now on by default — no action needed unless
# you were explicitly disabling it.

# Step 2: Install the T3-compatible SDK
# $ npm install @aspect-build/tempo-sdk@latest
#
# Verify you're on a T3-compatible version:
# $ npx tempo-sdk version
# > @aspect-build/tempo-sdk 4.3.0 (T3-compatible)

# Step 3: Create a scoped access key using TIP-1011
# This grants a dApp a session key that can only call a specific
# contract method and spend up to 5 TEMPO in gas + value transfers.

import { TempoClient, AccessKeyPermission } from "@aspect-build/tempo-sdk";

const client = new TempoClient({ network: "moderato" }); // testnet

# Connect the user's primary wallet / signer
const account = await client.connectAccount(primarySigner);

# Define the permission scope for the session key
const scopedPermission = new AccessKeyPermission({
  # Which contract can this key call?
  allowedContract: "0xAbC123...GameContract",

  # Which methods on that contract? Empty array = any method.
  allowedMethods: ["makeMove", "claimReward"],

  # Max total value (in base units) this key can spend
  spendingLimit: client.utils.parseUnits("5", 18),

  # Optional TTL — key expires after this duration
  ttlSeconds: 3600, // 1 hour session
});

# Generate a new session keypair and register it on-chain
const sessionKey = await account.addAccessKey(scopedPermission);

console.log("Session public key:", sessionKey.publicKey);
console.log("Spending limit:", scopedPermission.spendingLimit.toString());
console.log("Allowed methods:", scopedPermission.allowedMethods);

# The dApp backend can now sign transactions with sessionKey.privateKey
# and they will only succeed if they fall within the defined scope.
# Any call outside the scope (e.g., a transfer to an arbitrary address)
# will be rejected at the protocol level — not the application level.

# Step 4: Verify a WebAuthn signature on-chain using TIP-1020
# The precompile lives at a fixed address and supports secp256k1, P256,
# and WebAuthn signature formats.

import { SignatureVerifier } from "@aspect-build/tempo-sdk";

# Suppose a user signed a challenge using their device passkey (WebAuthn)
const webAuthnSignature = {
  authenticatorData: "0x49960de5...",
  clientDataJSON: '{"type":"webauthn.get","challenge":"..."}',
  signature: "0x3045...",  // DER-encoded P256 signature
  publicKey: "0x04...",     // uncompressed P256 public key
};

# Call the precompile to verify — this is a static call, no gas spent
# beyond the precompile's fixed cost.
const isValid = await SignatureVerifier.verifyWebAuthn(
  client,
  webAuthnSignature.authenticatorData,
  webAuthnSignature.clientDataJSON,
  webAuthnSignature.signature,
  webAuthnSignature.publicKey
);

console.log("WebAuthn signature valid:", isValid); // true or false

# Under the hood this calls the precompile at the TIP-1020 address:
# 0x0000000000000000000000000000000000001020
# You can also call it directly from Solidity:
#
# // Solidity example
# (bool success, bytes memory result) = address(0x1020).staticcall(
#     abi.encode(authData, clientData, sig, pubkey, SIG_TYPE_WEBAUTHN)
# );
# bool isValid = abi.decode(result, (bool));

# Step 5: Verify your contract deployment tooling against TIP-1016
# The CREATE opcode behavior has changed. If you have deployment scripts
# that compute expected contract addresses using the old nonce/address
# derivation, re-test them on Moderato before mainnet activation.
#
# Quick smoke test:
# $ npx hardhat run scripts/deploy.js --network moderato
# Compare the deployed address against your expected address computation.
# If they diverge, review TIP-1016 for the updated derivation spec.

# -------------------------------------------------------
# Key dates:
#   Moderato (testnet) activation: April 21, 2026
#   Presto (mainnet) activation:   April 27, 2026
#
# Operator checklist:
#   [x] Upgrade node to v1.6.0
#   [x] Remove --consensus.enable-subblocks from startup flags
#   [x] Migrate off validator config v1 (removed in PR #3561)
#   [x] Upgrade SDK to T3-compatible version
#   [x] Re-test contract deployments for TIP-1016 CREATE changes
# -------------------------------------------------------