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+# Registrar package
+
+The `registrar` pkg is used to handle node registration on ThreeFold Grid.
+
+The registration process includes:
+
+1. Collecting node information
+2. Creating/Ensuring a twinID exists for the node
+3. Registering the node on the blockchain
+
+## Error Handling
+
+`ErrInProgress` - Error raised if the node registration is still in progress.
+`ErrFailed` - Error raised if the node registration fails.
+
+## Constants
+
+### Node registration state constants
+
+`Failed` - Node registration failed
+`InProgress` - Node registration is in progress
+`Done` - Node registration is completed
+
+## Structs
+
+### State Struct
+
+used to store the state of the node registration.
+
+#### Fields
+
+`NodeID` - The ID of the node.
+`TwinID` - The twin ID of the node.
+`State` - The state of the node registration.
+`Msg` - The message associated with the node registration state.
+
+### RegistrationInfo Struct
+
+used to store the capacity, location, and other information of the node.
+
+#### Fields
+
+`Capacity` - The capacity of the node.
+`Location` - The location of the node.
+`SecureBoot` - The secure boot status of the node.
+`Virtualized` - The virtualized status of the node.
+`SerialNumber` - The serial number of the node.
+`GPUs` - The GPUs of the node.
+
+#### Methods
+
+`WithCapacity` - Set the capacity of the node, taking a `gridtypes.Capacity` as input.
+`WithLocation` - Set the location of the node, taking a `geoip.Location` as input.
+`WithSecureBoot` - Set the secure boot status of the node, taking a boolean as input.
+`WithVirtualized` - Set the virtualized status of the node, taking a boolean as input.
+`WithSerialNumber` - Set the serial number of the node, taking a string as input.
+`WithGPUs` - Set the GPUs of the node, taking a string as input.
+
+### Registrar Struct
+
+The registrar is used to register nodes on the ThreeFold Grid.
+
+#### Fields
+
+`state` - The state of the registrar.
+`mutex` - A mutex for synchronizing access to the registrar.
+
+#### Methods
+
+`NodeID` - Returns the node ID if the registrar is in the done state, otherwise returns an error.
+`TwinID` - Returns the twin ID if the registrar is in the done state, otherwise returns an error.
+
+## Functions
+
+### `FailedState(err error) State`
+
+Returns a failed state with the given error.
+
+### `InProgressState() State`
+
+Returns an in progress state.
+
+### `DoneState(nodeID , twinID uint32) State`
+
+Returns a done state with the given node ID and twin ID.
+
+### `NewRegistrar(ctx context.Context, cl Zbus.Client, env environment.Environment, info RegistrationInfo) *Registrar`
+
+Creates a new registrar with the given context, client, environment, and registration information, starts the registration process and returns the registrar.