Deterministic correctness testing for MCP servers. CLI, CI, and zero-config audit.
A single Go binary that connects to your MCP server over stdio, SSE, or HTTP, calls your tools, and asserts the results. Define assertions in YAML, run them in CI. Works with servers written in Go, TypeScript, Python, Rust, Java, or anything else that speaks MCP.
v0.12.3: Lint False Positive Fix
Fixed
E105/E107 false positive reduction (#23)
On servers with many tools sharing path/ID/content params (e.g., 65-tool code intelligence servers), E105 and E107 were generating thousands of unusable findings. This release eliminates the noise:
- E105 now skips params that are unconstrained by design: filesystem paths (*_path, *_file, *_dir), identifiers (*_id, *_uri), and free-text content (new_text, query, filter, command, description, scope, etc.)
- E107 collapses cycle variants to one finding per unique cycle (was reporting every path permutation)
- E107 downgraded from error to warning (circular deps are advisory)
Before (65-tool server): 2,784 E105 errors + 751 E107 errors = 3,535 unusable findings
After: 0 E105 errors, 2 E107 warnings
Real issues (missing descriptions, missing examples, schema drift) are no longer buried.
Upgrade Notes
If you pinned --threshold to a high number to work around E105/E107 noise, you can lower it now. --threshold 0 should work for well-documented servers.
| Publisher | Blackwell Systems |
|---|---|
| Version | 0.12.3 |
| Release date | 2026-06-04 |
| License | MIT |
| Installer type | zip |
| Architecture | x64, arm64 |
| Package ID | BlackwellSystems.mcp-assert |
winget install --id=BlackwellSystems.mcp-assert -ewinget upgrade --id=BlackwellSystems.mcp-assert -ewinget uninstall --id=BlackwellSystems.mcp-assert -eYes. mcp-assert is free and open-source software released under the MIT license.
The latest version is 0.12.3, released on Jun 4, 2026.
The download button links to the official installer published on github.com, the same file Windows Package Manager installs. You can verify the downloaded file by comparing its SHA-256 checksum with 62e33d01c47dccab7e72a5e7c038d5a7681c2aab450924ac17c9278e75836ae0.
mcp-assert runs on Windows and is available for 64-bit (x64), ARM64 systems.
Open Settings › Apps › Installed apps, find mcp-assert and select Uninstall. From the command line, run winget uninstall --id=BlackwellSystems.mcp-assert -e.
Yes. mcp-assert is available as a portable ZIP archive (mcp-assert_0.12.3_windows_amd64.zip, 64-bit (x64)) that runs without installation. Copy it to any folder or USB drive and run it from there.
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