Unseal FunctionCallContent/FunctionResultContent; make MCP types extend them #7201

Copilot · 2026-01-12T19:07:05Z

Takes over #7104 and augments it by making McpServerToolCallContent and McpServerToolResultContent inherit from FunctionCallContent and FunctionResultContent respectively, enabling unified approval handling for both regular functions and MCP server tools.

Changes

Core type hierarchy

Unsealed FunctionCallContent and FunctionResultContent to allow inheritance
McpServerToolCallContent extends FunctionCallContent, adding ServerName property (uses base Arguments property directly)
McpServerToolResultContent extends FunctionResultContent (uses base Result property directly)

Unified approval types (from #7104)

FunctionApprovalRequestContent accepts FunctionCallContent via FunctionCall property
FunctionApprovalResponseContent accepts FunctionCallContent via FunctionCall property
Deleted McpServerToolApprovalRequestContent and McpServerToolApprovalResponseContent

Client updates

FunctionInvokingChatClient: Direct access to FunctionCall property
OpenAIResponsesChatClient: Reordered switch cases (derived types before base types to avoid unreachable code)
Simplified idToContentMapping to use Dictionary<string, McpServerToolCallContent>

Breaking Changes

McpServerToolCallContent.Arguments changed from IReadOnlyDictionary<string, object?> to IDictionary<string, object?>
McpServerToolResultContent now uses Result property instead of Output

Compatibility

Added CP0008 suppressions for unsealing across all target frameworks

Tests

Added missing tests from PR Replace Mcp approvals with Function approvals #7104 for mixed MCP/Function approval scenarios
Changed test namespace from Microsoft.Extensions.AI.ChatCompletion to Microsoft.Extensions.AI

Example

// Before: Separate approval types for MCP and functions
var mcpApproval = new McpServerToolApprovalRequestContent(id, mcpToolCall);
var funcApproval = new FunctionApprovalRequestContent(id, functionCall);

// After: Unified approval type works with both
var mcpApproval = new FunctionApprovalRequestContent(id, mcpToolCall);  // mcpToolCall is FunctionCallContent
var funcApproval = new FunctionApprovalRequestContent(id, functionCall);

Original prompt

Can you take over #7104, augment it with implementing McpServerToolCallContent and McpServerToolResultContent by unsealing and extending FunctionCallContent and FunctionResultContent, add the necessary compatibility suppressions, update the branch and resolve conflicts.

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

Microsoft Reviewers: Open in CodeFlow

Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

…ew approval types Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

…ypes Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

jozkee

@copilot please fix errors and address feedback.

jozkee · 2026-01-12T20:37:54Z

src/Libraries/Microsoft.Extensions.AI.Abstractions/Contents/FunctionApprovalRequestContent.cs

+    /// Gets the call content that pre-invoke approval is required for.
    /// </summary>
-    public FunctionCallContent FunctionCall { get; }
+    public AIContent CallContent { get; }


CallContent can go back to be FunctionCallContent FunctionCall.

Done in commit 598f78b. Changed CallContent back to FunctionCallContent FunctionCall.

jozkee · 2026-01-12T20:38:23Z

src/Libraries/Microsoft.Extensions.AI.Abstractions/Contents/FunctionApprovalResponseContent.cs

+    /// Gets the call content for which approval was requested.
    /// </summary>
-    public FunctionCallContent FunctionCall { get; }
+    public AIContent CallContent { get; }


Done in commit 598f78b. Changed CallContent back to FunctionCallContent FunctionCall.

jozkee · 2026-01-12T20:40:56Z

src/Libraries/Microsoft.Extensions.AI.Abstractions/Contents/McpServerToolCallContent.cs

    /// </summary>
-    public IReadOnlyDictionary<string, object?>? Arguments { get; set; }
+    [JsonIgnore]
+    public new IReadOnlyDictionary<string, object?>? Arguments


instead of adding a new property, let's use the one in base, let's take the breaking change of switching from IReadOnlyDictionary<string, object?>.

Done in commit 598f78b. Removed the new property and using base class Arguments property directly (breaking change from IReadOnlyDictionary to IDictionary accepted).

jozkee · 2026-01-12T21:08:01Z

src/Libraries/Microsoft.Extensions.AI.Abstractions/Contents/McpServerToolResultContent.cs

+    [JsonIgnore]
+    public IList<AIContent>? Output
+    {
+        get => Result as IList<AIContent>;
+        set => Result = value;
+    }


Let's take the breaking change and use base.Result instead of Output and update the call sites as needed.

Done in commit 598f78b. Removed Output property and using base.Result instead (breaking change accepted). Updated all call sites in commits 29454f9.

jozkee · 2026-01-12T21:31:41Z

src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIResponsesChatClient.cs

                case McpToolCallApprovalResponseItem mtcari:
-                    message.Contents.Add(new McpServerToolApprovalResponseContent(mtcari.ApprovalRequestId, mtcari.Approved) { RawRepresentation = mtcari });
+                    // Approval responses are processed separately when converting tool messages (see ConvertToResponseItems).
+                    // They are not included in assistant message contents.
                    break;


This should be removed and let the code use the default case for McpToolCallApprovalResponseItem.

Done in commit 598f78b. Removed the case for McpToolCallApprovalResponseItem and letting it use the default case processing.

jozkee · 2026-01-12T21:43:32Z

src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIResponsesChatClient.cs

-
                        case McpServerToolResultContent mstrc:
                            if (idToContentMapping?.TryGetValue(mstrc.CallId, out AIContent? callContentFromMapping) is true &&
                                callContentFromMapping is McpServerToolCallContent associatedCall)


Not related to this change but can you change idToContentMapping to Dictionary<string, McpServerToolCallContent> and remove this condition, it should be fine since we are storing only one concrete type in it.

Done in commit 598f78b. Changed idToContentMapping from Dictionary<string, AIContent> to Dictionary<string, McpServerToolCallContent> and removed the condition check.

jozkee · 2026-01-12T21:54:39Z

...ies/Microsoft.Extensions.AI.Tests/ChatCompletion/FunctionInvokingChatClientApprovalsTests.cs

You missed a bunch of tests from https://github.com/dotnet/extensions/pull/7104/changes#diff-e6c178864ff9bd78b41577e6e0e8170e602af913f45a9108bfa830ea70739621.

Done in commits 598f78b and 23d5d20. Changed namespace to Microsoft.Extensions.AI and added all three missing tests:

FunctionCallReplacedWithApproval_MixedWithMcpApprovalAsync

ApprovedApprovalResponseIsExecuted_MixedWithMcpApprovalAsync

RejectedApprovalResponses_MixedWithMcpApprovalAsync

All tests updated to use Result property instead of Output.

…nts properties, fix idToContentMapping Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

…Dictionary, use Result instead of Output Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

Copilot · 2026-01-12T22:16:57Z

@copilot please fix errors and address feedback.

All feedback addressed in commits 598f78b, 23d5d20, and 29454f9. Changes include:

Reverted to FunctionCallContent FunctionCall in approval types
Removed wrapper properties from MCP types (breaking changes accepted)
Fixed idToContentMapping type and simplified logic
Added missing tests from PR Replace Mcp approvals with Function approvals #7104
Fixed all build errors (unused usings, type conversions, property renames)

Initial plan

6a3b94e

Copilot AI assigned Copilot and jozkee Jan 12, 2026

Copilot started work on behalf of jozkee January 12, 2026 19:07 View session

Copilot AI and others added 6 commits January 12, 2026 19:11

Unseal Function types and refactor MCP types to extend them

f44487e

Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

Update FunctionInvokingChatClient and OpenAIResponsesChatClient for n…

ebc033a

…ew approval types Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

Update test files for new approval content types

beb9517

Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

Update OpenAI tests and add compatibility suppressions for unsealed t…

aff14b3

…ypes Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

Fix switch case ordering for McpServerToolCallContent inheritance

2d45997

Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

Address code review feedback - add clarifying comments

8db0e74

Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Implement McpServerToolCallContent and McpServerToolResultContent~~ Unseal FunctionCallContent/FunctionResultContent; make MCP types extend them Jan 12, 2026

Copilot AI requested a review from jozkee January 12, 2026 19:39

Copilot finished work on behalf of jozkee January 12, 2026 19:39

jozkee requested changes Jan 12, 2026

View reviewed changes

Copilot started work on behalf of jozkee January 12, 2026 21:55 View session

dotnet-policy-service bot added the waiting-author-feedback 📭 The author of this issue needs to respond in order for us to continue investigating this issue. label Jan 12, 2026

Address review feedback: revert to FunctionCall, remove Output/Argume…

598f78b

…nts properties, fix idToContentMapping Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

dotnet-policy-service bot removed the waiting-author-feedback 📭 The author of this issue needs to respond in order for us to continue investigating this issue. label Jan 12, 2026

Copilot AI and others added 2 commits January 12, 2026 22:01

Add missing tests for mixed MCP/Function approval scenarios

23d5d20

Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

Fix build errors: remove unused usings, cast IReadOnlyDictionary to I…

29454f9

…Dictionary, use Result instead of Output Co-authored-by: jozkee <16040868+jozkee@users.noreply.github.com>

Copilot AI requested a review from jozkee January 12, 2026 22:19

Copilot finished work on behalf of jozkee January 12, 2026 22:19

Unseal FunctionCallContent/FunctionResultContent; make MCP types extend them #7201

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Unseal FunctionCallContent/FunctionResultContent; make MCP types extend them #7201

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Changes

Core type hierarchy

Unified approval types (from #7104)

Client updates

Breaking Changes

Compatibility

Tests

Example

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