MCP Substack Server
🤖 MCP Server for Substack integration with Claude AI Desktop. Download and parse Substack posts directly in your Claude conversations.
Caution. Specific findings reduced this grade. They are listed on the page. Grades reflect the full trust pyramid: code, verification depth, and reputation. New projects cap at C until adoption is earned.
How we verified
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⚡ Connect GitHub → continuous verification on every pushwhy connect →Who stands behind it
michalnaka
Source: mcp.so
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Install from
The grade above is for the source repository. Registries can serve a different version, so we mark the ones we were not able to read.
Disclosed vulnerabilities in this server's declared npm dependencies (via OSV). Whether each is reachable depends on the installed versions.
Model Context Protocol (MCP) TypeScript SDK does not enable DNS rebinding protection by default
Undici: Malicious WebSocket 64-bit length overflows parser and crashes the client
Undici has Unhandled Exception in WebSocket Client Due to Invalid server_max_window_bits Validation
Undici has Unbounded Memory Consumption in WebSocket permessage-deflate Decompression
undici WebSocket client vulnerable to denial of service via fragment count bypass
Tool annotations
No tools have read-only/destructive annotations
Add readOnlyHint or destructiveHint annotations to every tool so hosts can warn users before invoking.
All four hints declared on every tool
1/1 tools missing one or more hints — download_substack (missing: readOnlyHint, destructiveHint, idempotentHint, openWorldHint). OpenAI's directory rejects tools where any of the four hints are missing or non-boolean.
For every tool, set all four hints (readOnlyHint, destructiveHint, idempotentHint, openWorldHint) to explicit true/false values that match the handler’s actual behaviour.
License file
No license file
Add a LICENSE file (MIT, Apache-2.0, etc.).
Tests exist
No test files found
Add tests that exercise each declared tool.
Production dependencies are patched
0 critical, 5 high severity in production deps — @modelcontextprotocol/sdk@0.6.1 (high), undici@6.21.0 (high)
Run npm audit fix, or upgrade the affected packages to a non-vulnerable version.
Dependency freshness
1/4 production deps stale: node-fetch@2023-11-30 (2.8y)
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