Add MCP notifications/message for log streaming to clients#3484
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anushakolan wants to merge 3 commits intomainfrom
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Add MCP notifications/message for log streaming to clients#3484anushakolan wants to merge 3 commits intomainfrom
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anushakolan
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Aniruddh25,
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Aniruddh25
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May 1, 2026
Aniruddh25
reviewed
May 1, 2026
Aniruddh25
reviewed
May 1, 2026
Aniruddh25
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May 1, 2026
Aniruddh25
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May 1, 2026
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Pull request overview
Note
Copilot was unable to run its full agentic suite in this review.
Adds support for streaming server logs to MCP clients via notifications/message, enabling real-time log consumption after logging/setLevel is invoked.
Changes:
- Introduces MCP-specific logging components (
McpLogger,McpLoggerProvider,McpLogNotificationWriter) that emit logs as JSON-RPC notifications to stdout. - Centralizes MCP↔.NET log level mapping in
McpLogLevelConverterand wires it into dynamic log level handling. - Updates MCP stdio server to enable/disable log notifications based on
logging/setLeveland standardizes JSON-RPC version usage.
Reviewed changes
Copilot reviewed 9 out of 9 changed files in this pull request and generated 7 comments.
Show a summary per file
| File | Description |
|---|---|
| src/Service/Telemetry/DynamicLogLevelProvider.cs | Switches MCP level parsing to shared converter. |
| src/Service/Program.cs | Registers MCP notification writer/provider and clears default log providers in MCP stdio mode. |
| src/Service.Tests/UnitTests/McpLogNotificationTests.cs | Adds unit tests around MCP logger/provider enabled behavior. |
| src/Core/Telemetry/McpLogLevelConverter.cs | Adds shared MCP↔.NET log level conversion utility. |
| src/Azure.DataApiBuilder.Mcp/Telemetry/McpLoggerProvider.cs | Adds logger provider that caches per-category MCP loggers. |
| src/Azure.DataApiBuilder.Mcp/Telemetry/McpLogger.cs | Adds ILogger implementation that forwards logs to MCP notifications. |
| src/Azure.DataApiBuilder.Mcp/Telemetry/McpLogNotificationWriter.cs | Adds stdout JSON-RPC notification writer + interface for toggling. |
| src/Azure.DataApiBuilder.Mcp/Model/McpStdioJsonRpcErrorCodes.cs | Introduces shared JSON-RPC version constant. |
| src/Azure.DataApiBuilder.Mcp/Core/McpStdioServer.cs | Enables notifications on logging/setLevel and uses shared JSON-RPC version constant. |
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| Stream stdout = Console.OpenStandardOutput(); | ||
| _writer = new StreamWriter(stdout, new UTF8Encoding(encoderShouldEmitUTF8Identifier: false)) | ||
| { | ||
| AutoFlush = true | ||
| }; |
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| lock (_lock) | ||
| { | ||
| _writer?.WriteLine(json); | ||
| } |
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| [TestMethod] | ||
| public void McpLogNotificationWriter_IsEnabledFalseByDefault() | ||
| { | ||
| // Arrange & Act | ||
| McpLogNotificationWriter writer = new(); | ||
|
|
||
| // Assert | ||
| Assert.IsFalse(writer.IsEnabled); | ||
| } |
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| internal static class McpStdioJsonRpcErrorCodes | ||
| { | ||
| /// <summary> | ||
| /// JSON-RPC protocol version. | ||
| /// </summary> | ||
| public const string JSON_RPC_VERSION = "2.0"; |
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Aniruddh25
approved these changes
May 5, 2026
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Why make this change?
Enables MCP clients (like MCP Inspector, Claude Desktop, VS Code Copilot) to receive real-time log output via MCP
notifications/message.Related: #3274 (depends on PR #3419)
What is this change?
When
logging/setLevelis called with a level other than "none", logs are sent to MCP clients as JSON-RPC notifications:{ "jsonrpc": "2.0", "method": "notifications/message", "params": { "level": "info", "logger": "Azure.DataApiBuilder.Service.Startup", "data": "Starting Data API builder..." } }New files:
McpLogNotificationWriter.cs- Writes logs as MCP notifications to stdoutMcpLogger.cs/McpLoggerProvider.cs- ILogger implementation for .NET logging pipelineMcpLogNotificationTests.cs- Unit tests (8 tests)Modified files:
Program.cs- RegistersMcpNotificationWriterandMcpLoggerProviderfor MCP modeMcpStdioServer.cs- Enables notifications whenlogging/setLevelis calledHow was this tested?
logging/setLevelis sentNote
This PR targets
dev/anushakolan/set-log-level(PR #3419) as it depends on thelogging/setLevelimplementation.