bridge/interfaces/BridgeStrategy.md

Strategy interface for chain-specific bridge operations.

The Bridge SDK uses the Strategy pattern to abstract chain-specific logic:

• EthereumBridgeStrategy: Handles ERC-20 approvals, ethers.js signing
• SolanaBridgeStrategy: Handles SPL token accounts, @solana/web3.js signing

Each strategy encapsulates:

• Fee estimation for the target chain
• Outbound transfers (GalaChain → External)
• Inbound transfers (External → GalaChain)
• Status polling and transaction tracking

Properties

Property	Modifier	Type	Description
network	readonly	ExternalNetwork	The external network this strategy handles.

Methods

bridgeIn()

bridgeIn(params): Promise<BridgeTransaction>

Bridge tokens IN from external chain to GalaChain.

Flow:

1. Approve bridge contract (if needed)
2. Deposit tokens to bridge contract
3. Register the deposit with GalaConnect
4. Receive native tokens on GalaChain

Parameters

Parameter	Type	Description
params	BridgeInParams	Bridge in parameters

Returns

Promise<BridgeTransaction>

Transaction details with tracking info

---

bridgeOut()

bridgeOut(params): Promise<BridgeTransaction>

Bridge tokens OUT from GalaChain to external chain.

Flow:

1. Lock tokens on GalaChain (via GalaConnect)
2. Wait for bridge confirmation
3. Receive wrapped tokens on external chain

Parameters

Parameter	Type	Description
params	BridgeOutParams	Bridge out parameters

Returns

Promise<BridgeTransaction>

Transaction details with tracking info

---

estimateFee()

estimateFee(tokenSymbol): Promise<BridgeFeeEstimate>

Estimate bridge fees for a transfer (a per-transfer cost: it does not depend on the amount).

Parameters

Parameter	Type	Description
tokenSymbol	string	Token symbol (e.g., 'GALA', 'GUSDC')

Returns

Promise<BridgeFeeEstimate>

Fee estimate with breakdown

---

getStatus()

getStatus(transactionHash): Promise<BridgeStatus>

Get the current status of a bridge transaction.

Parameters

Parameter	Type	Description
transactionHash	string	The bridge transaction hash

Returns

Promise<BridgeStatus>

Current status with details

---

getSupportedTokens()

getSupportedTokens(): string[]

Get the list of supported tokens for this chain.

Returns

string[]

Array of token symbols supported by this bridge

---

isTokenSupported()

isTokenSupported(tokenSymbol): boolean

Check if a specific token is supported for bridging.

Parameters

Parameter	Type	Description
tokenSymbol	string	Token symbol to check

Returns

boolean

True if token can be bridged

---

isValidAddress()

isValidAddress(address): boolean

Validate a recipient address for the external chain.

Parameters

Parameter	Type	Description
address	string	Address to validate

Returns

boolean

True if address is valid for this chain

---

waitForCompletion()

waitForCompletion(transactionHash, options?): Promise<BridgeStatus>

Wait for a bridge transaction to complete.

Polls the transaction status until it reaches a terminal state (completed or failed) or the timeout is reached.

Parameters

Parameter	Type	Description
transactionHash	string	The bridge transaction hash
options?	WaitOptions	Polling options

Returns

Promise<BridgeStatus>

Final status when complete

Throws

GalaSDKError BRIDGE_STATUS_TIMEOUT if the timeout is reached first; INVALID_BRIDGE_OPTION for a poll interval or timeout that is not a finite number, 0 or more