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MCP Blast-Radius Auditor

Official registry Security

Static blast-radius audit for MCP servers before agent install. Manifest optional.

Source code Website Documentation

What can you do with MCP Blast-Radius Auditor?

  • aos_compliance_validate — scan one MCP server directory (target_dir required; tool_id optional label)
  • aos_compliance_self_test — wiring smoke test

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

PYPI package mcp-blast-radius
Claude Code 
claude mcp add mcp-blast-radius-auditor -- uvx mcp-blast-radius==0.2.8
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "mcp-blast-radius-auditor": {
            "command": "uvx",
            "args": [
                "mcp-blast-radius==0.2.8"
            ]
        }
    }
}

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. MCP Blast-Radius Auditor
  2. Try it in 3 steps
  3. Machine-readable metadata
  4. Example walkthrough
  5. Report a scan question
  6. 30-second scan
  7. Install
  8. CLI entry
  9. MCP tools
  10. What is extracted
  11. Environment
  12. Example
  13. License

MCP Blast-Radius Auditor

See what any MCP server can actually touch — before you add it to your agent.

No manifest? You still get the full blast-radius report. Add a manifest to also catch divergences.

Also, if the server declares a manifest: Catch an MCP server that touches files it said it wouldn't — and block the merge in CI.

Statically extract what a third-party MCP server can reach (files, network, subprocess, env) via surface-level analysis. Compare against declared boundaries when a manifest is present.

Scan scope (default): production package only — excludes tests/, docs/, examples/, scripts/, benchmarks/, .github/, and test_*.py patterns; JSON output includes scan_scope and excluded_file_count. Pass --include-peripheral to scan the full repo.

Try it in 3 steps

① Scan your server in one command

pip install mcp-blast-radius==0.2.5
mcp-blast-radius-gate --gate-mode advisory --target-dir /path/to/your-mcp-server

Point --target-dir at your shipping package root (e.g. src/). Default scope excludes tests, docs, and scripts.

② Read the JSON

FieldWhat it means
gate_passScan finished (advisory = report either way; blocking = exit 1 on divergences)
blocking_reasonsLines starting with DIVERGENCE: = declared vs. observed mismatch (if you ship a manifest)
blast_radiusStatic capability surface (network, subprocess, env, filesystem)
confidence labelsdeclared / observed-static / cannot-determine — static only, upper bounds

Undeclared capability is usually drift, not malice. Treat network/subprocess counts as upper bounds, not confirmed traffic.

③ Apply for an audit badge (optional, opt-in)

Ran a clean scan and want a signed README badge? Open a badge application — paste your command and JSON. Free, 90-day attestation, no phone-home. Criteria: BADGE_CRITERIA.md.

To verify any published attestation independently: pip install cryptography, then run packaging/scripts/verify_attestation.py (accepts local paths or HTTPS URLs). See BADGE_CRITERIA.md §Verify.

Machine-readable metadata

Example walkthrough

git clone --depth 1 https://github.com/oraios/serena.git /tmp/serena
mcp-blast-radius-gate --gate-mode advisory --target-dir /tmp/serena

Inspect blast_radius and any DIVERGENCE: lines in blocking_reasons.

Report a scan question

Open a GitHub issue with your JSON output (structured template loads automatically).

30-second scan

pip install mcp-blast-radius
mcp-blast-radius-gate --gate-mode blocking --target-dir /path/to/mcp-server

pipx run mcp-blast-radius starts the MCP stdio server (for Claude Desktop / Cursor). For CLI scanning, use mcp-blast-radius-gate as above.

  • Red (blocking): divergence detected — code touches paths or capabilities not declared in manifest.
  • Green: no divergences (or no manifest — blast radius report only, advisory pass).

Install

python3 -m venv .venv
source .venv/bin/activate
pip install .

CLI entry

mcp-blast-radius          # MCP stdio server
mcp-blast-radius-gate     # CI gate (default blocking, exit 1 on fail)
CI blocking gate
mcp-blast-radius-gate --gate-mode blocking --target-dir .
# no divergences → exit 0 / divergences or declaration violations → exit 1

MCP tools

  • aos_compliance_validate — scan one MCP server directory (target_dir required; tool_id optional label)
  • aos_compliance_self_test — wiring smoke test

Default gate_mode=advisory. Use gate_mode=blocking in CI to fail on divergences.

What is extracted

LayerScopeConfidence
Dependenciesrequirements.txt, pyproject.toml, package.jsondeclared
Python ASTimports, file I/O, network, env, subprocess; MCP tool attributionobserved-static / cannot-determine
Divergencemanifest permitted_output_paths / oracle_paths vs observed accessblocking when mismatch

Limitations: Static analysis only. Dynamic imports, getattr/eval, obfuscation, and native extensions may hide capabilities. We do not claim complete coverage — every finding includes a confidence label.

Environment

VariablePurpose
AOS_VALIDATOR_TARGET_DIRDefault scan root when target_dir is omitted
AOS_VALIDATOR_MCP_LOGJSONL path for local tool call log (never sent externally)
AOS_VALIDATOR_CALLERCaller label (ci, smoke_self_call, etc.)

Example

aos_compliance_validate target_dir=/path/to/my-mcp-server gate_mode=blocking

License

MIT

Frequently asked questions

What is MCP Blast-Radius Auditor?

Static blast-radius audit for MCP servers before agent install. Manifest optional.

How do I install MCP Blast-Radius Auditor?

It runs on your machine. In Claude Code: claude mcp add mcp-blast-radius-auditor -- uvx mcp-blast-radius==0.2.8. For other clients, paste the JSON configuration from this page into their MCP settings.

Does MCP Blast-Radius Auditor need an API key?

Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.

Is MCP Blast-Radius Auditor open source?

Yes. Its code is on GitHub under the MIT license.

Who maintains MCP Blast-Radius Auditor?

It is published by aos-standard. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.