Neo Standards Auto-Detection

Back to Standards and Contracts

The neo-solc compiler analyzes your contract's public methods and events to automatically detect which NEP standards it implements. Detection results populate the manifest's supportedstandards array.

NEP-17 Detection

All 5 methods must be present as public/external functions:

symbol, decimals, totalSupply, balanceOf, transfer

Additional rules:

• ownerOf must not be present (its presence signals NEP-11 instead)
• A Transfer event with 3 parameters is expected
• The transfer method should have 4 parameters (from, to, amount, data)
• Near-miss warning: if 3+ of 5 methods are present but not all, the compiler emits a warning listing the missing methods

NEP-11 Detection

Core requirement:

• balanceOf and ownerOf must both be present

Plus at least one of:

• transfer
• transferFrom
• tokensOf

Additional checks:

• A Transfer event with 4 parameters is expected
• The transfer method should have 3 parameters (to, tokenId, data)
• Near-miss warnings: ownerOf without a transfer mechanism, or ownerOf + transfer without balanceOf

NEP-24 Detection

Either of these methods triggers detection:

• tokenUri
• royaltyInfo

Additional NEP Detection

The compiler also auto-detects these contract-lifecycle and callback standards:

• NEP-22: update(nefFile, manifest, data)
• NEP-26: onNEP11Payment(from, amount, tokenId, data)
• NEP-27: onNEP17Payment(from, amount, data)
• NEP-29: _deploy(data, update)
• NEP-30: verify(...) -> bool
• NEP-31: destroy()

Checking Detection Results

After compilation, inspect the manifest to verify detected standards:

neo-solc MyToken.sol -I devpack -O2 -o build/MyToken
cat build/MyToken/MyToken.manifest.json | jq '.supportedstandards'
# Expected: ["NEP-17"]