MCPSpec
Ship reliable MCP servers without writing test code
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Hi HN,I've been building MCPSpec, an open-source CLI for MCP server reliability. Record sessions, generate mock servers, catch Tool Poisoning, and fail your CI build when something's wrong — without writing test code.There are ways to validate MCP servers today — the MCP Inspector, ad-hoc SDK scripts, unit tests for server internals — but nothing that handles regression detection, security auditing, mock generation, and CI pass/fail checks in one tool. MCPSpec does that:1. Record a session against your real server, replay it after changes to catch regressions2. Generate a standalone .js mock from any recording — no API keys, no live server needed in CI3. Security audit with 8 rules including Tool Poisoning (prompt injection hidden in tool descriptions)4. 0-100 quality score across documentation, schema quality, error handling, responsiveness, and security5. One command to generate GitHub Actions / GitLab CI configsNo LLMs in the loop. Deterministic and fast. Ships with 70 ready-to-run tests for 7 popular MCP servers.GitHub: https://github.com/light-handle/mcpspec Docs: https://light-handle.github.io/mcpspec/Would love feedback or feature ideas.
HN · launched Feb 25, 2026 · 7 upvotes (top 62%) · 0 views
Niche: mcp server developer tools · 108 launches, 12 in the last 7 days ▲ +50% · Explore this niche →
Category and tags
- Horizontal
- Observability & eval
- Developer
- AI-native
- Commercial product
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More like this: all 108 launches in mcp server developer tools →
Could you build this?
Yes MCPSpec is a CLI testing and mocking tool that communicates via the Model Context Protocol (JSON-RPC over stdio/SSE), running schema validation, recording responses, and asserting YAML rules.
Discussion
2 comments analyzed.
Competitors mentioned: MCP Inspector (Anthropic), MCP-Scan (Snyk), Promptfoo, MCP Protocol Validator
Concerns raised: No industry standards exist yet for MCP testing/compliance, Market still early, standards development just starting
Competitors
Other products that read as similar to this one : 403 launches clear the similarity bar, closest 8 shown.
Attention rank: #236 of 404 (itself plus its competitors, highest first, normalized so YC and Product Hunt are compared fairly).
Launched 118 days after the earliest competitor.
- Tool for Testing MCP Servers · hn · 2026-01-07 · 5 upvotes · similarity 0.57
- MCP Playground · hn · 2026-03-01 · 7 upvotes · similarity 0.56
- mcp-recorder · hn · 2026-03-06 · 6 upvotes · similarity 0.56
- Mcpscore · hn · 2026-08-04 · 10 upvotes · similarity 0.55
- mcpscore · ph · 2026-10-30 · 5 upvotes · similarity 0.53
- mcpward · ph · 2026-10-10 · 3 upvotes · similarity 0.53
- PlugMCP · ph · 2026-11-06 · 1 upvotes · similarity 0.52
- MCPJam · ph · 2026-09-17 · 141 upvotes · similarity 0.50
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