TRON TIP-712 Demo (TronBox + TronWeb)

A minimal, end-to-end example that demonstrates TIP-712 (TRON’s EIP-712 variant) by:

• deploying a small on-chain verifier contract with TronBox,
• signing a typed message off-chain with TronWeb, and
• verifying the signature locally and on-chain.

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What’s inside

• contracts/Tip712Verifier.sol – a tiny on-chain signature checker. It builds a fixed TIP-712 domain separator at deploy time (name, version, this contract’s address, TRON’s 32-bit chainId) and exposes verify(...) which recomputes the TIP-712 digest for a Mail message and uses ecrecover to confirm the signer.
• demo.js – Node.js script that constructs domain / types / value, signs the typed data via tronWeb.trx._signTypedData, normalizes the v byte (00/01 → 1b/1c), verifies locally, and then calls the contract’s verify to confirm on-chain.
• migrations/2_deploy_tip712.js – TronBox migration that deploys the verifier with NAME and VERSION from your environment.
• tronbox.js – networks & compiler settings (Nile by default).
• .env.sample – template for your local .env.

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TIP-712 on TRON (quick mental model)

• Domain = the stamp: { name, version, chainId(32-bit), verifyingContract }
  Binds a signature to one app/contract/chain → prevents replay elsewhere.
• Types = the form template: schema for your structs.
• Value = the filled form: the actual data you approve.

TRON specifics:

• Domain uses low 32 bits of block.chainid.
  • Mainnet: 0x2b6653dc
  • Nile: 0xcd8690dc
• Addresses are handled as 20-byte values under the hood.
• Some tools return signature v as 0/1; many verifiers expect 27/28 → normalize for compatibility.

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Project structure

TRON-TIP712-DEMO
├─ build/contracts/                # created by tronbox compile/migrate
├─ contracts/
│  ├─ Migrations.sol
│  └─ Tip712Verifier.sol
├─ migrations/
│  └─ 2_deploy_tip712.js
├─ demo.js
├─ tronbox.js
├─ .env           # your real secrets (not committed)
├─ .env.sample    # template
└─ package.json

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Prerequisites

• Node.js 20+
• TronBox CLI: npm i -g tronbox
• A TRON account private key with some Nile test TRX
• RPC endpoint (default in this repo): https://nile.trongrid.io

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1) Install

npm install
# (If you don't have TronBox globally)
npm i -g tronbox

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2) Configure environment

Copy .env.sample → .env, then edit:

FULL_HOST=https://nile.trongrid.io
PRIVATE_KEY=YOUR_PRIVATE_KEY_64HEX
NETWORK=nile

# TIP-712 domain values
NAME=TRON TIP-712 Demo
VERSION=1

# Set this after deployment (see step 3):
VERIFYING_CONTRACT=TP....................

Note: VERIFYING_CONTRACT is the deployed contract address (base58 T-address) you’ll paste after running migrations.

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3) Compile & deploy (Nile)

tronbox compile
tronbox migrate --reset --network nile

Grab the printed contract address (T-address) from migration output and put it in .env as VERIFYING_CONTRACT=.

If you see Could not find artifacts for ./Migrations, ensure contracts/Migrations.sol exists (and optionally add a migrations/1_initial_migration.js) then re-run tronbox compile.

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4) Run the demo

node demo.js

Expected output (example):

Signature: 0x<r...s...v>
Local verify: true
On-chain verify: true

• Local verify: true → TronWeb recovered your signer address from the signature.
• On-chain verify: true → the contract computed the same TIP-712 digest and ecrecover matched the expected signer.

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How it works (end-to-end)

1. Contract deploy creates a domain separator from (NAME, VERSION, uint32(chainId), address(this)) and stores it immutably.
2. demo.js builds the same domain, defines types and value, and calls _signTypedData to sign.
3. demo.js normalizes the signature v byte to 1b/1c (27/28) for broad compatibility.
4. demo.js checks locally with verifyTypedData(...) (no RPC required).
5. demo.js calls the contract’s verify(...) with:
   • Mail as tuples: [[from.name, from.wallet], [to.name, to.wallet], contents, nonce]
   • expectedSigner (your T-address)
   • signature
6. The contract reconstructs the same TIP-712 digest and runs ecrecover(...) to confirm the signer.

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Troubleshooting

• Artifacts not found (Tip712Verifier.json)
  Make sure you run node demo.js from the project root where build/contracts/Tip712Verifier.json exists (created by TronBox). The script uses process.cwd() to load the artifact.

• Could not find artifacts for ./Migrations
  Add contracts/Migrations.sol (and optionally migrations/1_initial_migration.js), then tronbox compile.

• Local verify: false
  Domain or message mismatch. Ensure name, version, verifyingContract, and 32-bit chainId match between JS and Solidity; also check nonce and string content.

• On-chain verify: false
  Same as above plus make sure the Mail struct is passed as tuples in the declared order.

• Rate limits / RPC errors
  Nile endpoint is public; mainnet often needs a TronGrid API key (TRON_PRO_API_KEY).

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Notes & extensions

• To port this to mainnet, set FULL_HOST=https://api.trongrid.io and use chainId=0x2b6653dc in your domain.
• You can wire verify(...) into state-changing functions (e.g., “if valid signature, then mint/transfer/execute”).
• TIP-712 also defines an atomic trcToken type (not used in this demo).

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License

MIT