Cosmos

Cosmos integration via OneKey's Keplr-compatible provider

Integrate Cosmos ecosystem chains using OneKey's Keplr-compatible provider. Access via window.$onekey.cosmos.

OneKey's Cosmos provider is fully compatible with the Keplr wallet interface, making migration seamless.

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Quick Links

• API Reference

• Chain Management

• Signing Messages

• Sending Transactions

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Provider Detection

// Detect OneKey Cosmos provider
const provider = window.$onekey?.cosmos

if (!provider) {
  throw new Error('OneKey Cosmos provider not detected')
}

// Check if it's OneKey
console.log('Provider:', provider.isOneKey ? 'OneKey' : 'Unknown')

---

Quick Start

Connect to Chain

const chainId = 'cosmoshub-4'

// Enable the chain - returns key info
const key = await provider.enable(chainId)

// Or enable multiple chains at once
await provider.enable(['cosmoshub-4', 'osmosis-1', 'juno-1'])

Get Account Info

const chainId = 'cosmoshub-4'
const key = await provider.getKey(chainId)

console.log({
  name: key.name,           // Account name
  algo: key.algo,           // Signing algorithm (secp256k1)
  pubKey: key.pubKey,       // Public key (Uint8Array)
  address: key.address,     // Bech32 address (Uint8Array)
  bech32Address: key.bech32Address,  // Bech32 formatted address
  isNanoLedger: key.isNanoLedger,    // Hardware wallet flag
})

---

Chain Management

Add Custom Chain

Use experimentalSuggestChain to add chains not natively supported:

await provider.experimentalSuggestChain({
  chainId: 'my-chain-1',
  chainName: 'My Custom Chain',
  rpc: 'https://rpc.mychain.io',
  rest: 'https://lcd.mychain.io',
  bip44: { coinType: 118 },
  bech32Config: {
    bech32PrefixAccAddr: 'mychain',
    bech32PrefixAccPub: 'mychainpub',
    bech32PrefixValAddr: 'mychainvaloper',
    bech32PrefixValPub: 'mychainvaloperpub',
    bech32PrefixConsAddr: 'mychainvalcons',
    bech32PrefixConsPub: 'mychainvalconspub',
  },
  currencies: [{
    coinDenom: 'TOKEN',
    coinMinimalDenom: 'utoken',
    coinDecimals: 6,
  }],
  feeCurrencies: [{
    coinDenom: 'TOKEN',
    coinMinimalDenom: 'utoken',
    coinDecimals: 6,
    gasPriceStep: { low: 0.01, average: 0.025, high: 0.04 },
  }],
  stakeCurrency: {
    coinDenom: 'TOKEN',
    coinMinimalDenom: 'utoken',
    coinDecimals: 6,
  },
})

Disconnect

await provider.disconnect()

---

Signing Messages

Sign Amino (Legacy)

For legacy Amino-encoded transactions:

const chainId = 'cosmoshub-4'
const signer = 'cosmos1...'

const signDoc = {
  chain_id: chainId,
  account_number: '0',
  sequence: '0',
  fee: {
    amount: [{ denom: 'uatom', amount: '5000' }],
    gas: '200000',
  },
  msgs: [{
    type: 'cosmos-sdk/MsgSend',
    value: {
      from_address: signer,
      to_address: 'cosmos1...',
      amount: [{ denom: 'uatom', amount: '1000000' }],
    },
  }],
  memo: '',
}

const result = await provider.signAmino(chainId, signer, signDoc)

console.log({
  signed: result.signed,       // Signed document
  signature: result.signature, // { pub_key, signature }
})

Sign Direct (Protobuf)

For modern Protobuf-encoded transactions:

const chainId = 'cosmoshub-4'
const signer = 'cosmos1...'

const signDoc = makeSignDoc(
  bodyBytes,      // Transaction body
  authInfoBytes,  // Auth info with fee
  chainId,
  accountNumber
)

const result = await provider.signDirect(chainId, signer, signDoc)

console.log({
  signed: result.signed,
  signature: result.signature,
})

Sign Arbitrary Data

For signing arbitrary messages (useful for authentication):

const chainId = 'cosmoshub-4'
const signer = 'cosmos1...'
const data = 'Login to MyApp at 2024-01-01T00:00:00Z'

const signature = await provider.signArbitrary(chainId, signer, data)

// Verify the signature
const isValid = await provider.verifyArbitrary(chainId, signer, data, signature)
console.log('Signature valid:', isValid)

---

Sending Transactions

Broadcast Transaction

const chainId = 'cosmoshub-4'
const txBytes = new Uint8Array([...]) // Signed transaction bytes

// Broadcast modes: 'block', 'sync', 'async'
const result = await provider.sendTx(chainId, txBytes, 'sync')

console.log('TX Hash:', result)

---

Offline Signers

Get offline signers for use with CosmJS:

const chainId = 'cosmoshub-4'

// Auto-detect best signer type
const offlineSigner = await provider.getOfflineSignerAuto(chainId)

// Or use specific signer types
const aminoSigner = provider.getOfflineSignerOnlyAmino(chainId)
const directSigner = provider.getOfflineSigner(chainId)

// Use with CosmJS
const client = await SigningStargateClient.connectWithSigner(
  'https://rpc.cosmos.network',
  offlineSigner
)

// Send tokens
const result = await client.sendTokens(
  senderAddress,
  recipientAddress,
  [{ denom: 'uatom', amount: '1000000' }],
  { amount: [{ denom: 'uatom', amount: '5000' }], gas: '200000' }
)

---

API Reference

Methods

Method	Description
enable(chainIds)	Enable chain(s) and get key info
disable(chainIds)	Disable chain(s)
disconnect()	Disconnect from all chains
getKey(chainId)	Get account key for chain
signAmino(chainId, signer, signDoc)	Sign Amino-encoded transaction
signDirect(chainId, signer, signDoc)	Sign Protobuf-encoded transaction
sendTx(chainId, tx, mode)	Broadcast signed transaction
signArbitrary(chainId, signer, data)	Sign arbitrary message
verifyArbitrary(chainId, signer, data, signature)	Verify signature
experimentalSuggestChain(chainInfo)	Add custom chain
getOfflineSigner(chainId)	Get Direct offline signer
getOfflineSignerOnlyAmino(chainId)	Get Amino-only offline signer
getOfflineSignerAuto(chainId)	Auto-detect best signer type

Key Interface

interface Key {
  name: string              // Human-readable name
  algo: string              // Signing algorithm
  pubKey: Uint8Array        // Public key bytes
  address: Uint8Array       // Address bytes
  bech32Address: string     // Bech32 formatted address
  isNanoLedger: boolean     // True if hardware wallet
  isKeystone: boolean       // True if Keystone hardware
}

Supported Chains

Chain	Chain ID	Native Support
Cosmos Hub	cosmoshub-4	Yes
Osmosis	osmosis-1	Yes
Juno	juno-1	Yes
Stargaze	stargaze-1	Yes
Akash	akashnet-2	Yes
Secret Network	secret-4	Yes
Custom	Any	Via experimentalSuggestChain

---

Error Handling

try {
  await provider.enable('cosmoshub-4')
} catch (error) {
  if (error.code === 4001) {
    console.log('User rejected the request')
  } else if (error.message.includes('not supported')) {
    console.log('Chain not supported, try experimentalSuggestChain')
  } else {
    console.error('Connection failed:', error)
  }
}

---

Migration from Keplr

OneKey's Cosmos provider is Keplr-compatible. Simply change your provider detection:

// Before (Keplr only)
const provider = window.keplr

// After (OneKey with Keplr fallback)
const provider = window.$onekey?.cosmos || window.keplr