Registries

Do I need this page?

Use as a lookup when you need to know exact method signatures, freeze timing, or return types
For beginners: you only need SpcNodeRegistry.register() — that's covered in the tutorial
Come back later when you start using context extensions, multiblock modules, network devices, or events

This is a reference page — you don't need to read it top to bottom.

Registry Overview

Registry	Package	Stores	Added In	Guide Page
`SpcNodeRegistry`	`api.registry`	Node schemas + factories + categories	v1	Core Concepts, Tutorial
`SpcContextExtensionRegistry`	`api.registry`	Execution context extensions	v1	Context Extensions
`SpcProgramBlockRegistry`	`api.registry`	Programming block categories + visual styles	1.1.0	API Reference
`SpcModuleTypeRegistry`	`api.multiblock`	Custom multiblock module types + I/O handlers		Multiblock Modules
`SpcNetworkRegistry`	`api.network`	Network device type definitions		Network Devices
`SpcRuntimeEventRegistry`	`api.event`	Runtime event listeners		Runtime Events

Registration Timing

All registrations must happen before the registry is frozen by SPC.

When to Register	How	Example
`@Mod` constructor	Call `register()` directly in your mod's constructor	`SpcNodeRegistry.register(schema, factory, category);`
`FMLCommonSetupEvent`	Register inside the event handler	`modBus.addListener(e -> SpcNodeRegistry.register(...));`

⚠️ Never register lazily

Do not register in ServerStartingEvent, LevelEvent.Load, or any per-world event. By that time, all registries are frozen.

Freeze Behavior

After mod loading completes, SPC calls freeze() on every registry.

After Freeze	Behavior
`register()`	Throws `IllegalStateException`
`find()` / `get()`	Works normally (read-only)
`all()`	Returns unmodifiable view
`isFrozen()`	Returns `true`

ℹ️ Do not call freeze() yourself

The freeze() method is internal to SPC. Addon mods should never call it.

SpcNodeRegistry

Package: com.hypernova.spc.api.registry
Storage: LinkedHashMap<String, SpcNodeRegistration> (preserves insertion order)
Thread safety: synchronized register, volatile frozen flag

Methods

Method	Returns	Parameters	Description
`register(SpcNodeSchema, ISpcNodeFactory, SpcNodeCategory)`	`void`	`schema` — node type declaration `factory` — compiled node creator `category` — palette group	Register a custom function block node type
`find(String typeId)`	`Optional<SpcNodeRegistration>`	`typeId` — the node type ID	Look up a registration
`all()`	`Map<String, SpcNodeRegistration>`	—	Unmodifiable view of all registrations
`isFrozen()`	`boolean`	—	Whether frozen
`freeze()`	`void`	—	Internal

SpcNodeRegistration (inner record)

Component	Type	Description
`schema`	`SpcNodeSchema`	The node type definition (ports, params, phase)
`factory`	`ISpcNodeFactory`	Creates compiled node instances
`category`	`SpcNodeCategory`	Editor palette category

Exceptions

Condition	Exception
Register after freeze	`IllegalStateException`
Duplicate typeId	`IllegalArgumentException`
Null schema/factory/category	`NullPointerException`

SpcContextExtensionRegistry

Package: com.hypernova.spc.api.registry
Storage: LinkedHashMap<Class<?>, ISpcExecutionContextExtension>
Thread safety: synchronized register, volatile frozen flag

Methods

Method	Returns	Parameters	Description
`register(Class<T>, T instance)`	`void`	`extensionType` — interface class (lookup key) `instance` — implementation	Register a context extension
`get(Class<T>)`	`Optional<T>`	`extensionType`	Look up a registered extension by type
`all()`	`Map<Class<?>, ISpcExecutionContextExtension>`	—	Unmodifiable view of all extensions
`notifyTickStart(ServerLevel, BlockPos)`	`void`	`level`, `machinePos`	Internal — calls `onTickStart()` on all extensions
`isFrozen()`	`boolean`	—	Whether frozen
`freeze()`	`void`	—	Internal

Exceptions

Condition	Exception
Register after freeze	`IllegalStateException`
Duplicate extension type	`IllegalArgumentException`
Null type/instance	`NullPointerException`

SpcProgramBlockRegistry

Package: com.hypernova.spc.api.registry
Storage: LinkedHashMap<String, SpcProgramBlockCategory>
Thread safety: synchronized register, volatile frozen flag

Allows addons to register custom programming block categories with distinct visual styles. Each category defines a themed variant of the programming block (custom tint colors). Categories without an explicit style default to the brass palette.

Methods

Method	Returns	Parameters	Description
`register(SpcProgramBlockCategory)`	`void`	`category`	Register a programming block category
`find(String)`	`Optional<SpcProgramBlockCategory>`	`categoryId`	Look up by ID
`all()`	`Map<String, SpcProgramBlockCategory>`	—	Unmodifiable view of all categories
`isFrozen()`	`boolean`	—	Whether frozen
`freeze()`	`void`	—	Internal

Example Registration

SpcProgramBlockRegistry.register(new SpcProgramBlockCategory(
    "mymod:advanced_programmer",
    "Advanced Programmer",
    new SpcProgramBlockStyle(0xFF4488CC, 0xFF2255AA, 0xFF66BB6A)
));

Exceptions

Condition	Exception
Register after freeze	`IllegalStateException`
Duplicate categoryId	`IllegalArgumentException`
Null category	`NullPointerException`

SpcModuleTypeRegistry

Package: com.hypernova.spc.api.multiblock
Storage: ConcurrentHashMap<String, SpcModuleTypeRegistration>
Thread safety: ConcurrentHashMap + volatile frozen flag

Methods

Method	Returns	Parameters	Description
`register(SpcModuleType, ISpcPhysicalIoHandler)`	`void`	`moduleType`; `ioHandler` (nullable for non-I/O)	Register a module type with its handler
`register(SpcModuleType)`	`void`	`moduleType`	Register non-I/O module (handler = null)
`find(String moduleTypeId)`	`Optional<SpcModuleTypeRegistration>`	`moduleTypeId`	Look up a registration
`all()`	`Map<String, SpcModuleTypeRegistration>`	—	Unmodifiable view
`isFrozen()`	`boolean`	—	Whether frozen
`freeze()`	`void`	—	Internal

SpcModuleTypeRegistration (inner record)

Component	Type	Description
`moduleType`	`SpcModuleType`	The module type definition
`ioHandler`	`ISpcPhysicalIoHandler`	I/O handler (null for non-I/O modules)

SpcNetworkRegistry

Package: com.hypernova.spc.api.network
Storage: ConcurrentHashMap<String, SpcNetworkDeviceType>
Thread safety: ConcurrentHashMap + volatile frozen flag

Methods

Method	Returns	Parameters	Description
`registerDeviceType(String, String)`	`void`	`deviceTypeId`, `displayName`	Register a device type
`findDeviceType(String)`	`Optional<SpcNetworkDeviceType>`	`deviceTypeId`	Look up a type
`allDeviceTypes()`	`Map<String, SpcNetworkDeviceType>`	—	Unmodifiable view
`isFrozen()`	`boolean`	—	Whether frozen
`freeze()`	`void`	—	Internal

SpcNetworkDeviceType (inner record)

Component	Type	Description
`deviceTypeId`	`String`	Unique identifier
`displayName`	`String`	Editor display name

SpcRuntimeEventRegistry

Package: com.hypernova.spc.api.event
Storage: CopyOnWriteArrayList<ISpcRuntimeEventListener>
Thread safety: CopyOnWriteArrayList (inherently thread-safe)

Methods

Method	Returns	Parameters	Description
`register(ISpcRuntimeEventListener)`	`void`	`listener` — non-null	Register a runtime event listener
`all()`	`List<ISpcRuntimeEventListener>`	—	Unmodifiable snapshot
`freeze()`	`void`	—	Internal

Side-by-Side Comparison

Property	NodeRegistry	ContextExt	ModuleType	Network	Event
Key type	`String`	`Class<?>`	`String`	`String`	—
Value type	Registration	Extension	Registration	DeviceType	Listener
Backing store	LinkedHashMap	LinkedHashMap	ConcurrentHashMap	ConcurrentHashMap	CopyOnWriteArrayList
Allows duplicates	No	No	No	No	Yes
Has `find()`	Yes	Yes (`get`)	Yes	Yes	No
Has `isFrozen()`	Yes	Yes	Yes	Yes	No
Tick callback	No	Yes	No	No	No
API version	1.1.0	1.1.0	1.1.0	1.1.0	1.1.0

Common Mistakes

Mistake	Symptom	Fix
Registering in `ServerStartingEvent`	`IllegalStateException: … is frozen`	Move registration to `@Mod` constructor or `FMLCommonSetupEvent`
Duplicate type ID	`IllegalArgumentException` / `IllegalStateException`	Namespace your IDs: `"mymod:type"` instead of `"type"`
Calling `freeze()` from addon	Other addons can't register anymore	Never call `freeze()` — SPC does it automatically
Forgetting to register I/O handler	Module works structurally but signals are always zero	Use `register(moduleType, handler)` not `register(moduleType)`
Not namespacing IDs	Collisions with other addons	Always use `"yourmod:name"` format

← Previous Runtime Events Next → API Reference

Do I need this page?

On this page

Registry Overview

Registration Timing

Freeze Behavior

SpcNodeRegistry

Methods

SpcNodeRegistration (inner record)

Exceptions

SpcContextExtensionRegistry

Methods

Exceptions

SpcProgramBlockRegistry

Methods

Example Registration

Exceptions

SpcModuleTypeRegistry

Methods

SpcModuleTypeRegistration (inner record)

SpcNetworkRegistry

Methods

SpcNetworkDeviceType (inner record)

SpcRuntimeEventRegistry

Methods

Side-by-Side Comparison

Common Mistakes