Core subpath exports

@open-matrix/core/package.json declares an exports map (package.json:23-324) that gates which paths consumers can import from. The map allows the root barrel and a precise list of deep subpaths. This page is the table of every subpath, what it provides, and the import idiom to use.

How to read the table

Each row gives:

• Subpath — the string after @open-matrix/core/....
• Headline export — the most-used named export, for orientation. Subpaths often re-export several names; consult the source file or index.ts for the full list.
• When to use — which audiences and contexts the subpath is for.

The root barrel

Subpath	Imports
@open-matrix/core	The root barrel. Re-exports everything in src/index.ts. Default import path for application code.

import {
  MatrixActor, MatrixRuntime, MatrixActorHtmlElement,
  InMemoryTransport, InMemoryBroker, NatsTransport, createTransport,
  RequestReply, requestReply,
  resolveConfiguredPackageConfig, deepMergeConfig,
  ActivityFrame, isTerminalPhase,
  TopicRouter, MxEnvelope,
} from '@open-matrix/core';

If you don't have a specific reason to use a deep subpath, use the root barrel.

Core actor surface

Subpath	Headline export
core/MatrixActor	MatrixActor (the actor base class)
core/IRecordStoreProvider	IRecordStoreProvider, RECORD_STORE_PROVIDER_KEY
core/security/ICapabilityToken	ICapabilityToken
core/security/ISecurityRealm	ISecurityRealm
core/security/ITopicClaim	ITopicClaim
core/security/SecurityRealm	SecurityRealm, DEFAULT_SECURITY_POLICY
core/security/TopicClaimRegistry	TopicClaimRegistry
core/security/defaults	Default security policy values

Use the deep subpath when you only need a single class and want bundlers to tree-shake aggressively (for browser webapps that target small bundles).

Engine layer

Subpath	Headline export
engine/core/IMatrixContext	IMatrixContext (interface)
engine/core/MatrixContext	MatrixContext (class)
engine/messaging/TopicRouter	TopicRouter (subject computation)
engine/remoting/ComponentProxy	ComponentProxy
engine/remoting/IIntrospectResult	IIntrospectResult
engine/remoting/ITransportAdapter	ITransportAdapter, TransportAdapter (alias)
engine/remoting/RequestReply	RequestReply, requestReply
engine/utils/NameUtils	NameUtils, toHandlerCase

engine/* is the messaging plumbing. Use these subpaths when implementing transports or middleware. Application actors usually import everything from the root barrel.

Framework layer (browser-side)

Subpath	Headline export
framework/MatrixActorHtmlElement	MatrixActorHtmlElement (the browser actor base)
framework/ActivityFrame	ActivityFrame, ActivityPhase, isTerminalPhase
framework/IStateStore	IStateStore, STATE_STORE_KEY
framework/PageManifest	PageManifest, PageManifestEntry, buildCodeRef, createEmptyManifest, addManifestEntry, removeManifestEntry
framework/components/MxSplit	MxSplit (split-pane primitive)
framework/components/MxTheme	MxTheme (theme propagation)
framework/components/MxTopicTag	MxTopicTag (topic display)
framework/components/index	All shell primitives via a barrel

UI packages typically import the elements they need directly:

import { MxSplit } from '@open-matrix/core/framework/components/MxSplit';

Runtime layer

Subpath	Headline export
runtime/MatrixRuntime	MatrixRuntime
runtime/ComponentFactory	createFromSchema, ICreateResult, ICreateOptions
runtime/InstanceBootstrapContext	InstanceBootstrapContext
runtime/InstanceBootstrapRefs	InstanceBootstrapRefs
runtime/MountedInstanceMetadata	MountedInstanceMetadata
runtime/PackageConfigResolver	resolveConfiguredPackageConfig, deepMergeConfig, IPackageConfigContract, IPackageConfigProviderDeclaration

Use these when building a runner (a custom Host Service equivalent) or testing runtime-level behaviour.

Transports

Subpath	Headline export
transport/InMemoryBroker	InMemoryBroker
transport/InMemoryTransport	InMemoryTransport, InMemoryTransportOptions
transport/NatsTransport	NatsTransport, INatsTransportOptions, INatsLikeConnection, INatsLikeMsg, INatsLikeSubscription
transport/TransportProxy	TransportProxy

Use when constructing transports yourself (tests, bespoke runners). Application code uses the transport the runtime provides.

Browser bootstrap

Subpath	Headline export
browser/AppReadySignal	AppReadySignal
browser/BrowserProfileTrace	BrowserProfileTrace
browser/HostedRuntimeRecovery	HostedRuntimeRecovery
browser/HostedRuntimeTarget	HostedRuntimeTarget
browser/MatrixDSLHost	MatrixDSLHost (the bootstrap host element)

Flow / orchestration

Subpath	Headline export
flow/FlowBuilder	FlowBuilder
flow/FlowEngine	FlowEngine
flow/FlowPlan	IFlowPlan, cloneFlowPlan
flow/FlowTypes	Flow stage type unions
flow/viewers	Flow viewer barrel
flow/viewers/ViewTypeRegistry	ViewTypeRegistry

LISP

Subpath	Headline export
lisp	The LISP-on-protocol runtime barrel
lisp/vlm	The VLM submodule

Note: LISP and membrane subpaths are exported but treated as experimental. Surface may move; APIs may change without a full deprecation cycle.

Serialization

Subpath	Headline export
serialization	Top-level serialization helpers
serialization/IComponentSchema	IComponentSchema

Compatibility shims

Subpath	Note
_node-compat	DOM stubs for Node imports. Imported automatically by the root barrel.
core/MatrixActor.js	.js alias of core/MatrixActor. Compatibility for tools that produce .js import specifiers.
runtime/MatrixRuntime.js	Same — .js alias.
runtime/InstanceBootstrapContext.js	Same.
runtime/InstanceBootstrapRefs.js	Same.
runtime/MountedInstanceMetadata.js	Same.
engine/remoting/RequestReply.js	Same.
transport/InMemoryBroker.js	Same.
transport/InMemoryTransport.js	Same.
transport/NatsTransport.js	Same.

The .js aliases exist because some downstream toolchains (notably TypeScript projects with moduleResolution: "node" plus relative .js imports) write the literal .js extension into the import specifier. The aliases keep them resolving.

Picking root barrel vs deep subpath

Situation	Pattern
Application actor or webapp	Root barrel. import { MatrixActor, ... } from '@open-matrix/core'.
Bundler-sensitive browser library	Deep subpath. Smaller dependency graph for tree-shaking.
Test that builds a runtime by hand	Either. Deep subpath is fine for transport modules; root barrel is fine for everything else.
Building a transport or runner	Deep subpath into engine/, runtime/, transport/.

See also

• Public API ledger — the named exports per subpath.
• SDK package layout — the source-tree map this maps to.
• Stability levels — which exports are stable.

Source: projects/matrix-3/packages/core/package.json:23-324 (exports map, full).