Copilot SDK v0.2.1-preview.0: Commands & Blob Attachments

TL;DR

• Node.js SDK now supports slash commands and interactive UI prompts (confirm, select, text input)
• All SDKs gain custom model listing via onListModels callback for BYOK setups
• New blob attachment type for sending base64 image data without disk writes
• Breaking changes in Go: enum naming convention and struct name updates

New

• Commands and UI prompts for Node.js — Register slash commands and show interactive dialogs (confirm, select, text input) in sessions, bringing Node.js to feature parity with other SDKs.
• Custom model listing callback — All SDKs now accept onListModels in client options, letting you override model discovery for BYOK scenarios where you control the provider.
• Blob attachments — Send base64-encoded images directly to sessions without writing to disk first, useful for screenshots and in-memory generated content.
• Skip permission prompts for safe tools — Tools can now set skipPermission: true to bypass per-use permission dialogs.

Fixed

• Node.js CommonJS compatibility — SDK can now be require()d in VS Code extensions and other CommonJS contexts.
• Node.js cliPath handling — cliPath is now properly ignored when cliUrl is already set.
• C# SessionEvent serialization — Fixed ToJson() failing for events with JsonElement-backed members.
• C# unknown session events — Unknown event types no longer throw; returned as UnknownSessionEvent preserving raw JSON.
• C# AOT serialization crash — Fixed crash when CancellationToken fires during JSON-RPC operations.
• Go enum naming — All enum constants now use TypeNameValue convention (e.g., SessionEventTypeSessionIdle).
• Go struct naming — Removed Rpc suffix from struct names in the rpc package.
• Go Session.SetModel signature — Now takes *SetModelOptions instead of variadic argument.
• Python workspace_path flexibility — workspace_path in CopilotSession now accepts any os.PathLike value.

Breaking Changes

• Go enum constants — Update references from unprefixed names to the new TypeNameValue convention (e.g., SessionIdle → SessionEventTypeSessionIdle).
• Go struct names — Remove Rpc suffix from struct references in the rpc package.
• Go Session.SetModel — Change variadic calls to pass *SetModelOptions pointer instead.
• Python private modules — telemetry, jsonrpc, and sdk_protocol_version are now marked private; don't import directly.

Update via npm install @github/copilot-sdk@0.2.1-preview.0 (Node.js), or check your language's package manager for the latest version.

Source: Copilot SDK