@canmi/seam-client

Framework-agnostic client for calling seam procedures, subscribing to server events, and managing real-time connections.

Key Exports

| Export | Purpose | | ------------------------ | ------------------------------------------------------------------------------ | | createClient | Create a SeamClient instance with call(), subscribe(), fetchManifest() | | SeamClientError | Typed error class with error codes | | ReconnectController | Automatic reconnection with exponential backoff | | defaultReconnectConfig | Default reconnect configuration | | parseSseStream | Fetch-based SSE stream parser | | seamRpc | Low-level RPC call helper | | configureRpcMap | Configure RPC hash map for obfuscated endpoints | | createChannelHandle | Create an SSE-based channel handle | | createWsChannelHandle | Create a WebSocket-based channel handle | | prefetchRoute | Prefetch route data for faster navigation | | clearPrefetchCache | Clear prefetched route cache |

Types

| Type | Purpose | | ----------------- | ---------------------------------------------------------------- | | ConnectionState | Reconnection state (connected, reconnecting, disconnected) | | ReconnectConfig | Reconnect configuration (maxRetries, baseDelay, etc.) | | SseCallbacks | Callback interface for SSE stream events | | ChannelHandle | Handle for managing channel connections | | ErrorCode | String union of standard error codes | | ProcedureKind | 'query' \| 'command' \| 'subscription' \| 'stream' \| 'upload' |

Structure

• src/index.ts — Public API exports
• src/client.ts — SeamClient implementation (RPC calls, SSE subscriptions)
• src/errors.ts — SeamClientError typed error class
• src/reconnect.ts — ReconnectController with exponential backoff
• src/sse-parser.ts — Fetch-based SSE stream parser with Last-Event-ID support
• src/rpc.ts — seamRpc / configureRpcMap low-level RPC helpers
• src/channel-handle.ts — SSE-based channel handle
• src/ws-channel-handle.ts — WebSocket-based channel handle
• src/prefetch.ts — Route prefetching
• src/prefetch-cache.ts — Prefetch cache management
• src/batch.ts — Batch RPC call support

Development

• Build: just build-ts
• Test: just test-ts

Notes

• Used directly for vanilla JS or as a dependency of @canmi/seam-react
• subscribe() uses fetch-based SSE with Last-Event-ID reconnection support
• ReconnectController handles automatic reconnection with configurable exponential backoff