implement mcp logging

[antholeole]

Description

implement MCP logging protocol https://modelcontextprotocol.io/specification/2025-03-26/server/utilities/logging

Scenarios Tested

I used the MCP inspector. Note that the spec is not well defined in that it does not specify which log level is default. I opened a PR against the inspector to send a default log level (modelcontextprotocol/inspector#611) but this works without it, you just have to explicitly set log level in the inspector

[gemini-code-assist]

Summary of Changes

Hello @antholeole, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request integrates the Model Context Protocol (MCP) logging specification into the server. It enables the server to emit structured log messages to connected MCP clients and allows clients to dynamically control the server's logging verbosity. The changes include adding new types, capabilities, a logging API, and a private method for handling log message formatting and filtering.

Highlights

• MCP Logging Protocol Implementation: I've implemented the Model Context Protocol (MCP) logging specification, enabling the server to send structured log messages to connected MCP clients. This includes adding necessary types (LoggingLevel, SetLevelRequestSchema) and registering the logging capability with the MCP server.
• Dynamic Log Level Management: The server now supports dynamic adjustment of its logging verbosity. A new currentLogLevel property stores the active log level, which can be updated by the client via a SetLevelRequestSchema handler. Log messages are filtered based on this configured level.
• Convenient Logging API: I've exposed a public readonly logger object on the FirebaseMcpServer class, providing a convenient API for sending log messages at various levels (e.g., server.logger.warn('my warning')). This abstracts away the underlying MCP message sending.
• Structured Log Message Formatting: A private log method handles the actual sending of log messages. It automatically formats string messages into JSON objects ({ message: '...' }) to comply with the MCP protocol's requirement for JSON data, and applies log level filtering before sending.

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[antholeole]

/gemini review

[gemini-code-assist]

Code Review

This pull request implements the MCP logging protocol. The changes include adding capabilities for logging, handling log level setting from the client, and providing a logger utility for internal use. The implementation correctly filters logs based on the client-specified level. My review focuses on improving the performance and robustness of the log level checking mechanism by using a Map for lookups instead of Array.indexOf.

[gemini-code-assist]

Code Review

The pull request implements MCP logging, adding logging capabilities to the Firebase MCP server. The changes include defining log levels, setting the log level via request, and sending log messages. The suggestions aim to improve code clarity, prevent potential runtime errors, and enhance performance.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 52.03%. Comparing base (609bb02) to head (9725bbc).
Report is 30 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8846      +/-   ##
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+ Coverage   51.97%   52.03%   +0.06%     
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  Files         407      412       +5     
  Lines       30315    30480     +165     
  Branches     6276     6302      +26     
==========================================
+ Hits        15755    15861     +106     
- Misses      13143    13198      +55     
- Partials     1417     1421       +4     

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[joehan]

LGTM, feel free to merge whenever