What is multicall?
- Author
- CRYPTO PORT Editorial
- Published
- Updated
- Reading time
- 4 min
In short
Multicall bundles several calls into a single transaction. It lowers fees and, if one step fails, the whole thing reverts so no half-finished state is left behind. The downside is that the signing prompt shows a bundle, making it harder to see everything you are approving at once.
Key points
- Bundles multiple calls into one transaction
- Either everything succeeds or everything reverts
- Reduces both fees and waiting
- Makes the signing prompt harder to read
Definition
A pattern that executes several contract calls in sequence within one transaction. It is used both to batch read-only queries and to group state-changing actions.
Showing ten token balances on a screen means ten round trips if queried one by one. Bundled into a multicall it is a single round trip and the screen fills faster. Read-only batching costs no fee, which is why nearly every app uses it internally.
The same applies to state-changing work. Granting an allowance and swapping, or depositing into several pools, can all sit in one transaction: one fee, and no chance of a block boundary leaving things half done. If any step fails the whole bundle reverts.
As a user, the thing to watch is that bundling makes review harder. A wallet may not itemise the contents and can simply say 'multiple actions'. An unexpected allowance hidden inside the bundle will not stand out on screen.
Watch out for
- · A bundle can contain an allowance you did not intend to grant
- · If your wallet cannot itemise the bundle, you cannot fully review it before approving
- · One failing step reverts everything while the fee is still spent