MATSAFE
Headless Eclipse MAT MCP server for Java heap dump analysis
Overview
From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.
Headless MCP server for Eclipse MAT using direct java -jar org.eclipse.equinox.launcher_*.jar execution.
Features
mat_healthcheck— Validate MAT launcher and Java runtime availabilitymat_parse_report— Run predefined MAT reports (leak suspects, system overview, etc.)mat_oql_query— Execute OQL queries and return inline resultsmat_run_command— Execute 56 built-in MAT analysis commands (histogram, dominatortree, path2gc, threadoverview, etc.)mat_index_status— Check whether MAT index artifacts exist for a heap dumpmat_oql_spec— Return OQL parser guidance and supported patterns
Supported Commands (mat_run_command)
Dominator tree analysis
dominator_tree, show_dominator_tree, immediate_dominators, big_drops_in_dominator_tree
Path to GC roots
path2gc, merge_shortest_paths, gc_roots
Histogram & object listing
histogram, delta_histogram*, list_objects, group_by_value, duplicate_classes
Leak detection
leakhunter, leakhunter2, `find_leaks`, `find_leaks2`, reference_leak
Thread analysis
thread_overview, thread_details, thread_stack
Collection analysis
collection_fill_ratio, collections_grouped_by_size, array_fill_ratio, arrays_grouped_by_size, hash_entries, map_collision_ratio, extract_list_values, hash_set_values, primitive_arrays_with_a_constant_value
Reference analysis
references_statistics, weak_references_statistics, soft_references_statistics, phantom_references_statistics, finalizer_references_statistics
Finalizer analysis
finalizer_overview, finalizer_thread, finalizer_queue, finalizer_in_processing, finalizer_thread_locals
Retained set
show_retained_set, customized_retained_set
Component & top consumers
component_report, component_report_top, top_consumers, top_consumers_html, pie_biggest_objects
String & memory waste
find_strings, waste_in_char_arrays
Heap inf
668269cd42a6OBSERVED · 2026-10-09Connect
Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control.
claude mcp add mcp-mat -- npx -y [email protected]
Exposed tools (6)
3 read · 3 write · 0 destructive.
| Tool | Risk | Description |
|---|---|---|
mat_healthcheck | read | Validate MAT launcher and Java runtime availability. |
mat_index_status | read | Report whether MAT index artifacts already exist for a heap dump. |
mat_oql_query | write | Execute a single MAT OQL query and return result artifacts. |
mat_oql_spec | read | Return MAT OQL parser-mode guidance, supported patterns, and known limitations. |
mat_parse_report | write | Run a predefined MAT report headlessly and return generated artifacts. |
mat_run_command | write | Execute a named MAT analysis command headlessly and return result artifacts. |
Trust audit
SAFEgrade B · trust 89/100 Nothing in the source contradicts what it says it does. Grade A is reserved for packages that have also passed the behavioural sandbox.
| Layer | What it checks | Result |
|---|---|---|
| L0 | Provenance & inventory | PASS |
| L1 | Static analysis of the code | PASS |
| L2 | Instruction surface (what it tells the agent) | PASS |
| L3 | Class-specific surface | PASS |
| L4 | Behavioural (sandbox) | SKIPPED |
What the source does
- Filesystem
- none-observed
- Network
- none-observed
- Shell
- declared (1 observation(s))
- Dependencies
- not all pinned
- Secrets in source
- none-found
Findings (1)
@modelcontextprotocol/sdk, zod, @types/node, tsx, typescript
Gates applied: no_behavioural_pass.
668269cd42a6full audit observations/trust-audit/mcp-server/codelipenghui__mat.json · Report an issue / request a re-scanAudit history
Every audit this server has had. A grade with a past is a grade somebody is still checking.
| Date | Source | Verdict | Grade | Score | Change |
|---|---|---|---|---|---|
| 2026-10-09 | 668269cd42a6 | SAFE | B | 89 | first audit |
Questions
What is the MAT MCP server?
Headless Eclipse MAT MCP server for Java heap dump analysis
What tools does MAT expose?
6 in total: 3 read-only, 3 that write, and 0 that can delete or overwrite. Every one is listed on this page with its risk.
Is MAT safe to connect to an agent?
The audit found nothing in the source that contradicts what it says it does, and graded it B (89/100). Grade A is held back for packages that have also passed a sandboxed behavioural run, which is why a clean server reads B.
What credentials does MAT need?
No credential environment variables were found in its source, so it appears to need none.
How does MAT run?
It speaks stdio, so it runs as a local process your client starts. It is published on npm as mcp-mat at 0.1.0.
How current is this page?
The grade is for one exact copy of the source (668269cd42a6), read on 2026-10-09. The repository is watched and re-audited when it changes.