A bridge route works only if its source and destination token contracts still match the assets you intend to move. If an issuer changes a token’s contract, first find out whether it upgraded the same contract or migrated holders to a new address; that distinction determines whether an old route can still deliver the token you expect.
Start by identifying what changed
A token’s ticker and name are labels; its contract address identifies the token on a particular network. The same asset can have different addresses on Ethereum and Base, and two contracts can display the same ticker while representing different tokens. Check the address on the chain where your tokens are held and the official issuer’s announcement before choosing a route.
- Same address, new logic: a proxy may keep its address while its implementation changes.
- New address: the issuer may have deployed a replacement token that holders must claim or swap into.
- Chain-specific change: the issuer may update a token on one network while versions on other networks remain as they were.
- Bridge representation change: the bridge may change which destination contract it mints or releases.
With a proxy upgrade, users continue calling the same proxy address, which forwards calls to replaceable logic. EIP-1967 describes a common way to store that implementation address. A router that identifies the token by the unchanged proxy address may still select it, although the new logic can affect how that contract behaves.
A migration to a new address is different: the old token does not become the new token automatically. Holders usually need an issuer-defined migration, such as swapping old tokens for new ones at a stated ratio. ERC-20 itself does not define a universal migration process, so look for the issuer’s specific instructions rather than assuming a bridge performs the conversion.
A router matches addresses across a route
A bridge router builds a path from the token contract on your starting chain to a token contract on the destination chain. It can combine a bridge, which moves value between networks, with a decentralized exchange (DEX), which swaps one token for another. The Socket API’s route documentation describes requests in terms of source and destination chains and tokens, rather than relying on a ticker alone.
For example, imagine Northstar USD migrates from contract OLD to contract NEW on Base, while its Ethereum version remains at address ETH. A route from Ethereum to Base can still target OLD if the router’s token data and bridge integration have not been updated. A route targeting NEW may instead be available if the bridge or a DEX can deliver that version. These are illustrative contract labels, not real addresses or a claim about a particular token.
In practice, this is where Bungee Bridge fits: Bungee is a cross-chain aggregator built by Socket that finds routes across bridges and DEXs. When an upgrade is involved, treat a route as a proposed path between specific chain-and-contract pairs, then compare its destination token with the address the issuer says holders should receive.
Trace what happens from source to destination
A typical route begins with a quote for a source token, amount, and destination token. The route may first swap the source asset, then lock it in a bridge contract or burn it (remove it from circulation). A message or relayer coordinates delivery on the destination chain, where a bridge may release existing tokens or mint a corresponding representation; a final swap may convert that representation into the requested token.
Every step depends on the contracts and instructions encoded for that route. If the quote was prepared before a migration, its destination step may still refer to the old address. An upgrade at the same proxy address can also matter if it changes transfer rules or other behavior the bridge depends on. A router cannot infer an issuer’s migration policy from matching token names.
Before submitting, compare the destination contract in the route details with the issuer’s official destination address. If a route ends in the old contract, check whether that version is still accepted or redeemable. If the quote does not make the token identity clear, pause and check the issuer’s announcement and the relevant chain explorer. Never use an address sent only in an unsolicited message.
Refresh the route after an upgrade
Once you confirm which contract you need, request a fresh quote with the intended destination token. A new quote gives the router a chance to use current token and route data; it does not guarantee that every bridge has already added the migrated token. If no suitable route appears, use the issuer’s documented migration first, then bridge the replacement token if it is supported.
Check the expected amount as well as the address. Token decimals determine how on-chain units map to displayed amounts, and a migration ratio may mean that one old token does not equal one new token. The issuer’s terms define that conversion; a bridge quote only estimates the route’s output after its bridge and swap steps.
Bungee Bridge can help compare routes when the source or destination token is involved in a cross-chain transfer, but the issuer remains the authority on which contract represents its current token. Identify the chain and address, establish whether the change is a proxy upgrade or a migration, and refresh the quote before sending.