> **Can't find what you're looking for?** Use `search_docs` on the docs MCP server at `https://sdk.railnet.org/api/mcp` to find what you need.

# Deploying a vehicle

A vehicle spawn is one transaction against a vehicle factory. The Aave V3, ERC-4626, Morpho Blue
and wrapper factories all take the same modules, salts and initial deposit; only the asset the
vehicle wraps differs between them. See
[`buildSpawnAaveV3VehicleCall`](/actions/buildSpawnAaveV3VehicleCall),
[`buildSpawnErc4626VehicleCall`](/actions/buildSpawnErc4626VehicleCall),
[`buildSpawnMorphoBlueVehicleCall`](/actions/buildSpawnMorphoBlueVehicleCall) and
[`buildSpawnWrapperVehicleCall`](/actions/buildSpawnWrapperVehicleCall) for what is specific to
each.

## Before the spawn

1. **Modules.**
   * `accessControl`: the ExternalAccessControl that gates the vehicle. It must come from the
     access control factory this one trusts, or the call reverts `NotDeployedByFactory`.
   * `queryRegistry`: the registry the vehicle records its queries in. Must be a contract
     (`InvalidQueryRegistry`).
   * `feeManager` (optional): must come from the trusted FeeManager factory when set. The zero
     address skips the check and leaves the vehicle without one.
   * `modulesManager` (optional): same rule as `feeManager`, against the trusted ModulesManager
     factory.
2. **Role.** The caller needs `FACTORY_SPAWN` on the factory's access control.
3. **The initial deposit.** The factory pulls a seed deposit of the vehicle's asset from the
   caller and burns the shares it mints; the deposit does not come back. Read the amount with
   [`getInitialDepositAmount`](/actions/getInitialDepositAmount) and approve the factory for at
   least that much.

## The spawn

Every vehicle spawn takes two salts from [`randomSalt`](/utilities/randomSalt): `querySalt` for
the seed deposit query, and `deploymentSalt` for the vehicle itself. Generate `deploymentSalt` and
keep the value. The factory folds its own deployment counter into the address, so unlike a
conduit's, a vehicle's address cannot be predicted ahead of the call. You only get it back from
the receipt.

## After the spawn

Each factory has its own receipt helper:
[`extractAaveV3VehicleAddress`](/utilities/receiptHelpers#extractaavev3vehicleaddress),
[`extractErc4626VehicleAddress`](/utilities/receiptHelpers#extracterc4626vehicleaddress),
[`extractMorphoBlueVehicleAddress`](/utilities/receiptHelpers#extractmorphobluevehicleaddress) and
[`extractWrapperVehicleAddress`](/utilities/receiptHelpers#extractwrappervehicleaddress). Each
takes the transaction receipt and the factory address, and returns the deployed vehicle address, or
`null` if the spawn is not in it.