web3-validator

library2.0.6jsnpmunverified

JSON-Schema compatible validator used internally by web3.js v4 for validating addresses, bytes, numbers, and other Ethereum data types. Current version 2.0.6 (stable), part of the web3.js v4 monorepo with a release cadence aligned to web3.js releases. It wraps ajv and adds Ethereum-specific validators. Key differentiator: integrates directly with web3.js 4.x for automatic input validation, but can be used standalone. Compared to @ethersproject/address or @ethereumjs/util, it provides a full JSON Schema validator with custom keywords (e.g., 'bytes', 'address') and supports Ethereum ABI types.

devops

npm install web3-validator

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · WEB3-VALIDATOR

web3-validator

devopsjavascriptv2.0.6

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

Web3Validator

✓ import { Web3Validator } from 'web3-validator'

✗ const { Web3Validator } = require('web3-validator')

ESM-only since v2; CommonJS require will fail. Use dynamic import() if needed.

isAddress

✓ import { isAddress } from 'web3-validator'

✗ import { isAddress } from 'web3-utils'

isAddress was moved from web3-utils to web3-validator in web3@4.x. Using the old import will break.

validate

✓ import { validate } from 'web3-validator'

Default export not available; always use named import.

Creates a Web3Validator instance and uses it to validate an Ethereum address and a hex string against JSON Schema with custom formats.

import { Web3Validator } from 'web3-validator'; const validator = new Web3Validator(); // Validate an Ethereum address const schema = { type: 'string', format: 'address' }; try { validator.validate(schema, '0x742d35Cc6634C0532925a3b844Bc9e7595f9b9c8'); console.log('Valid address'); } catch (error) { console.error('Invalid:', error.message); } // Validate a hex string const hexSchema = { type: 'string', format: 'hexString', minLength: 64, maxLength: 64 }; try { validator.validate(hexSchema, '0x' + 'a'.repeat(64)); console.log('Valid hex'); } catch (error) { console.error('Invalid:', error.message); }

Debug

Known issues

breakingRemoved CommonJS support — ESM-only since v2.0.0. require() will throw Module not found.

fix

Use import syntax or dynamic import('web3-validator').

affects: >=2.0.0

breakingisAddress was moved from web3-utils to web3-validator in web3@4.x. Importing from web3-utils returns undefined.

fix

Import { isAddress } from 'web3-validator'.

affects: >=2.0.0

deprecatedThe validate method with single argument (instance-only) is deprecated; pass schema and data separately.

fix

Use validator.validate(schema, data) instead of validator.validate(data).

affects: >=1.0.0 <3.0.0

gotchaCustom formats like 'address' are only recognized if the format keyword is used; 'pattern' or custom keywords may not validate addresses correctly.

fix

Always use 'format': 'address' for Ethereum address validation.

affects: >=1.0.0

gotchaCross-fetch dependency may cause issues in non-browser/Node environments (e.g., React Native).

fix

Set environment polyfills or use a bundler plugin to handle fetch.

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: Web3Validator is not a constructor

Using require() instead of import with ESM-only package.

fix

Change to 'import { Web3Validator } from 'web3-validator'.

Error: Cannot find module 'web3-validator'

Package not installed or using CommonJS in Node <14.

fix

Run 'npm install web3-validator' and ensure Node >=14.

ValidationError: Invalid address provided

Passing an invalid Ethereum address to validate with format 'address'.

fix

Ensure the address is a 40-character hex string prefixed with '0x' and checksummed if using EIP-55.

Upgrade

Version history

2.0.6latest on npm

Audit

Dependencies

ethereum-cryptographyrequiredused internally for address/bytes validation

ajvrequiredJSON-Schema validation engine

cross-fetchrequiredrequired for network-related validations

Agent activity

13 hits · last 30 days

node

Resources

githubhttps://github.com/ChainSafe/web3.js ↗

packageweb3-validator ↗

homepagehttps://github.com/ChainSafe/web3.js#readme ↗