Plumb Extension SDK Path Through Session Create And Resume

[MRayermannMSFT]

What

Adds an extensionSdkPath option to the session-creation and session-resume surfaces of the Node.js, Go, Python, Rust, and .NET SDKs. Callers can now point the host at a local copilot-sdk/ folder that should be injected into extension subprocesses for that session, in place of whatever @github/copilot-sdk was bundled with the CLI that the SDK depends on.

The field is intentionally absent from implementations of joinSession, because by the time an extension joins, its subprocess has already been forked with whatever SDK the host chose.

Java is unchanged because it does not yet expose the broader extension surface (requestExtensions, canvases, etc.) — when that lands, this field should be added alongside it using the same pattern.

Why

A corresponding runtime PR added extensionSdkPath to the JSON-RPC session.create and session.resume payloads, but each language SDK only forwards explicitly-named fields. Without this passthrough, SDK consumers had no first-class way to test or pin a custom @github/copilot-sdk build end-to-end short of dropping down to raw JSON-RPC or rebuilding the entire host CLI. Adding the field across all currently-supported SDKs keeps the per-language surface in sync with the runtime and lets extension authors and SDK integrators iterate on SDK changes with a single typed option.

[github-actions]

Generated by SDK Consistency Review Agent for issue #1494 · ● 2.8M

[github-actions]

Generated by SDK Consistency Review Agent for issue #1494 · ● 4.2M

[Copilot]

Pull request overview

Adds extensionSdkPath plumbing to session create/resume surfaces so SDK callers can direct extension subprocesses to use a local copilot-sdk/ folder instead of the bundled runtime SDK.

Changes:

• Adds public/session config fields for extensionSdkPath across Node.js, Go, Python, Rust, and .NET.
• Forwards the new field into session.create and session.resume wire payloads.
• Bumps the Node.js @github/copilot dependency to the runtime version that supports the new payload field.

Show a summary per file

File	Description
rust/src/wire.rs	Adds the serialized wire field for create/resume requests.
rust/src/types.rs	Adds Rust config fields, defaults, debug output, builders, and wire conversion.
python/copilot/client.py	Adds Python create/resume parameters and payload serialization.
nodejs/src/types.ts	Documents and exposes extensionSdkPath on session config.
nodejs/src/extension.ts	Updates JoinSessionConfig typing to omit extensionSdkPath.
nodejs/src/client.ts	Forwards extensionSdkPath in create/resume RPC calls.
nodejs/package.json	Updates the runtime dependency version.
nodejs/package-lock.json	Locks the updated runtime and platform packages.
go/types.go	Adds Go config/request fields and JSON tags.
go/client.go	Copies the Go config field into create/resume requests.
dotnet/src/Types.cs	Adds the .NET config property and clone support.
dotnet/src/Client.cs	Adds the .NET request field and forwards it in create/resume calls.

Copilot's findings

Files not reviewed (1)

• nodejs/package-lock.json: Language not supported

• Files reviewed: 11/12 changed files
• Comments generated: 1

[github-actions]

Cross-SDK Consistency Review ✅

This PR maintains strong cross-SDK consistency. Here's a summary of findings:

SDK	create/createSession	resume/resumeSession	joinSession handling
Node.js	✅ extensionSdkPath	✅ extensionSdkPath	✅ Omitted from JoinSessionConfig type + stripped at runtime for untyped callers
Python	✅ extension_sdk_path	✅ extension_sdk_path	N/A — no join_session
Go	✅ ExtensionSdkPath	✅ ExtensionSdkPath	N/A — no JoinSession
.NET	✅ ExtensionSdkPath	✅ ExtensionSdkPath	N/A — no JoinSession
Rust	✅ extension_sdk_path + with_extension_sdk_path() builder	✅ extension_sdk_path + with_extension_sdk_path() builder	N/A — no join_session
Java	Intentionally deferred	Intentionally deferred	N/A

Naming follows language conventions throughout:

• TypeScript/Node: extensionSdkPath (camelCase)
• Python: extension_sdk_path (snake_case)
• Go/.NET: ExtensionSdkPath (PascalCase)
• Rust: extension_sdk_path (snake_case), builder with_extension_sdk_path()

Notable: The Node.js extension.ts defensively strips extensionSdkPath at runtime (not just at type level) to guard against untyped JS callers — a thoughtful extra precaution consistent with the stated intent.

No consistency issues found. The Java deferral is well-justified in the PR description.

Generated by SDK Consistency Review Agent for issue #1494 · ● 5.4M · ◷