README.md
On-demand .NET memory profiling with AI-actionable code fix suggestions
MemoryLens MCP
On-demand .NET memory profiling with concrete, AI-actionable code fix suggestions — wraps JetBrains dotMemory with a heuristic-based rule engine.
Quick Start
VS Code / Visual Studio (via dnx)
Add to your MCP settings (.vscode/mcp.json or VS settings):
{
"servers": {
"memorylens": {
"type": "stdio",
"command": "dnx",
"args": ["MemoryLens.Mcp", "--yes"]
}
}
}
Claude Code Plugin
claude install gh:MarcelRoozekrans/memorylens-mcp
.NET Global Tool
dotnet tool install -g MemoryLens.Mcp
Prerequisites
- .NET 10 SDK or later
Available MCP Tools
| Tool | Description |
|---|---|
ensure_dotmemory |
Downloads and verifies the JetBrains dotMemory CLI tool is available |
list_processes |
Lists running .NET processes available for profiling |
snapshot |
Captures a single memory snapshot of a target process |
compare_snapshots |
Captures two snapshots with configurable delay and compares them |
analyze |
Runs the rule engine against a captured snapshot and returns findings |
get_rules |
Lists all available analysis rules with their metadata |
Built-in Rules
| ID | Severity | Category | Description |
|---|---|---|---|
| ML001 | critical | leak | Event handler leak detected |
| ML002 | critical | leak | Static collection growing unbounded |
| ML003 | high | leak | Disposable object not disposed |
| ML004 | high | fragmentation | Large Object Heap fragmentation |
| ML005 | medium | retention | Object retained longer than expected |
| ML006 | medium | allocation | Excessive allocations in hot path |
| ML007 | medium | retention | Closure retaining unexpected references |
| ML008 | low | allocation | Array/list resizing without capacity hint |
| ML009 | low | pattern | Finalizer without Dispose pattern |
| ML010 | low | pattern | String interning opportunity |
Configuration
Create a .memorylens.json file in your project root to customize rule behavior:
{
"rules": {
"ML001": { "enabled": true, "severity": "critical" },
"ML002": { "enabled": true, "severity": "critical" },
"ML003": { "enabled": true, "severity": "high" },
"ML004": { "enabled": true, "severity": "high" },
"ML005": { "enabled": true, "severity": "medium" },
"ML006": { "enabled": true, "severity": "medium" },
"ML007": { "enabled": true, "severity": "medium" },
"ML008": { "enabled": true, "severity": "low" },
"ML009": { "enabled": true, "severity": "low" },
"ML010": { "enabled": true, "severity": "low" }
}
}
Usage Examples
Single Snapshot
Capture a memory snapshot of a running process to inspect current memory state:
> /memorylens
> Take a snapshot of my running API (PID 12345)
Claude will call ensure_dotmemory, then snapshot with the target PID, then analyze the result and present findings ordered by severity.
Before/After Comparison
Detect memory growth by comparing two snapshots taken with a delay:
> /memorylens
> Check if my app has a memory leak — compare before and after processing 1000 requests
Claude will call compare_snapshots with a configurable wait period, then analyze the diff to identify objects that grew between snapshots.
License
Tools (6)
ensure_dotmemoryDownloads and verifies the JetBrains dotMemory CLI tool is availablelist_processesLists running .NET processes available for profilingsnapshotCaptures a single memory snapshot of a target processcompare_snapshotsCaptures two snapshots with configurable delay and compares themanalyzeRuns the rule engine against a captured snapshot and returns findingsget_rulesLists all available analysis rules with their metadataConfiguration
claude_desktop_config.json
{"servers": {"memorylens": {"type": "stdio", "command": "dnx", "args": ["MemoryLens.Mcp", "--yes"]}}}Try it
→Take a snapshot of my running API (PID 12345) and analyze it for memory leaks.
→Check if my app has a memory leak by comparing two snapshots taken before and after processing 1000 requests.
→List all available memory analysis rules and their severity levels.
→Identify why my .NET process is consuming excessive memory using the latest snapshot.