Crate host_extensions 

host-extensions — extension framework for the Polkadot app host bridge.

Extensions live under window.host.ext.<namespace> in the SPA WebView. First-party extensions reuse the core hostBridge channel and __hostCall / __hostResolve / __hostPush plumbing — they only contribute a JS injection script that populates window.host.ext.*.

Implementing an extension

1. Implement HostExtension — provide a namespace, a channel name, a JS injection script, and a message handler.
2. Register the extension with an ExtensionRegistry.
3. Call ExtensionRegistry::combined_inject_script and inject the result after HOST_API_BRIDGE_SCRIPT.

See the extensions guide for the full lifecycle, the JS contract, and the graduation path from ext.* to core.

Re-exports

pub use first_party::crdt::CrdtExtension;

pub use first_party::crdt_runtime::CrdtRuntime;

pub use first_party::crdt_runtime::CrdtRuntimeError;

pub use first_party::crdt_runtime::InMemoryCrdtRuntime;

pub use first_party::data::DataExtension;

pub use first_party::media::MediaExtension;

pub use first_party::mesh::MeshExtension;

pub use first_party::mesh_runtime::current_time_ms;

pub use first_party::mesh_runtime::generate_session_nonce;

pub use first_party::mesh_runtime::private_object_result;

pub use first_party::mesh_runtime::InMemoryMeshConfig;

pub use first_party::mesh_runtime::InMemoryMeshRuntime;

pub use first_party::mesh_runtime::MeshPrivateControlWireMessage;

pub use first_party::mesh_runtime::MeshPrivateReceiptWireMessage;

pub use first_party::mesh_runtime::MeshPrivateWireQuery;

pub use first_party::mesh_runtime::MeshRuntime;

pub use first_party::mesh_runtime::MeshWireQuery;

pub use first_party::mesh_runtime::MeshWireReply;

pub use first_party::mesh_runtime::StoredMeshObject;

pub use first_party::mesh_runtime::StoredPrivateMeshObject;

pub use first_party::mesh_runtime::MESH_PRIVATE_CONTROL_CHANNEL;

pub use first_party::mesh_runtime::MESH_PRIVATE_QUERY_CHANNEL;

pub use first_party::mesh_runtime::MESH_PRIVATE_RECEIPT_CHANNEL;

pub use first_party::mesh_runtime::MESH_QUERY_CHANNEL;

pub use first_party::mesh_runtime::MESH_REPLY_CHANNEL;

pub use registry::ExtensionRegistry;

Modules

events

Canonical event names and payload types for __hostPush events.

executor_contract

Executor contract — canonical response types and error constants for window.host.* bridge calls.

first_party

First-party extensions shipped with host-sdk.

manifest

protocol

Media & data signaling protocol constants.

registry

trait_def

Structs

FilesExtension

HostPushEvent

Traits

HostExtension

A host extension contributes a JS injection script and a message handler.