Add displayPrompt support to session.send across all SDKs

[devm33]

Summary

Add a displayPrompt field to the session.send RPC params across all language SDKs. When provided, this value is shown in the conversation timeline instead of the actual prompt text.

Changes

• Rust (rust/src/types.rs, rust/src/session.rs): Added display_prompt: Option<String> field to MessageOptions with a with_display_prompt() builder method, serialized as displayPrompt in params.
• Node.js (nodejs/src/types.ts, nodejs/src/session.ts): Added optional displayPrompt to MessageOptions interface and pass it through in send().
• Python (python/copilot/session.py): Added display_prompt keyword argument to send() and send_and_wait().
• Go (go/types.go, go/session.go): Added DisplayPrompt field to MessageOptions and sessionSendRequest.
• Java (java/src/main/java/.../rpc/MessageOptions.java, SendMessageRequest.java, CopilotSession.java): Added displayPrompt field with getter/setter and pass it in send().
• .NET (dotnet/src/Types.cs, dotnet/src/Session.cs): Added DisplayPrompt property to MessageOptions and SendMessageRequest, passed in SendAsync().

Motivation

The GitHub app sends prompts that may contain additional context (e.g., canvas context, system instructions) prepended to the user's message. The displayPrompt field lets the app tell the runtime what to show in the timeline as the user's message, rather than showing the full enriched prompt.

[Copilot]

Pull request overview

Adds support in the Rust SDK for an optional “display-only” prompt label when sending a message, aligning Rust with the existing displayPrompt parameter used in other language SDKs and the JSON-RPC schema.

Changes:

• Extend MessageOptions with display_prompt: Option<String> plus a with_display_prompt() builder.
• Include displayPrompt in the session.send JSON-RPC params when display_prompt is set.

Show a summary per file

File	Description
rust/src/types.rs	Adds the display_prompt option and builder method to MessageOptions.
rust/src/session.rs	Serializes displayPrompt into session.send params when provided.

Copilot's findings

• Files reviewed: 2/2 changed files
• Comments generated: 1

[Copilot]

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 0 new

[github-actions]

Cross-SDK Consistency Review

This PR adds displayPrompt support to Go, Java, Node.js, Python, and Rust — great cross-SDK coverage! However, .NET is missing the equivalent change.

The .NET SDK needs updates in three places:

1. dotnet/src/Types.cs — MessageOptions class (after line 2796):

/// <summary>
/// If provided, this is shown in the timeline instead of <see cref="Prompt"/>.
/// </summary>
public string? DisplayPrompt { get; set; }

Also update the Clone() copy constructor to include DisplayPrompt = other.DisplayPrompt.

2. dotnet/src/Session.cs — SendMessageRequest record (after RequestHeaders, line 1673):

[JsonPropertyName("displayPrompt")]
public string? DisplayPrompt { get; init; }

3. dotnet/src/Session.cs — SendAsync method (in the SendMessageRequest initializer, after RequestHeaders):

DisplayPrompt = options.DisplayPrompt,

Without these changes, .NET consumers won't be able to set a display prompt, creating a feature gap relative to the other four SDKs.

Generated by SDK Consistency Review Agent for issue #1470 · ● 3.6M · ◷