Heap Seance
Summoning retained objects from the heap — so you can interrogate what refuses to die.
An MCP server + CLI toolkit that channels the spirits of jcmd, jmap, jstat, jfr, Eclipse MAT, and async-profiler into a structured leak investigation workflow — designed to run inside Claude Code.
2 slash commands. 8 MCP tools. Conservative by default.
How It Works • Quick Start • MCP Tools • Workflow • Prerequisites • Contributing
How It Works
Heap Seance follows a two-stage escalation model. No deep forensics unless the evidence demands it.
/leak-scan /leak-deep
| |
v v
3x class histogram (all of scan, plus)
+ GC pressure snapshot JFR recording
| heap dump
v MAT leak suspects
monotonic growth? async-profiler alloc profile
old-gen pressure? |
| v
+--- both true? -----> auto-escalate to deep
|
+--- otherwise ------> verdict + next stepsConfidence is earned, not assumed. high requires at least two independent strong signals. A single growing class is watch. Growth plus GC pressure is suspicious. Add a MAT dominator or JFR correlation and you get probable_memory_leak.
