The io.github.mnemox-ai/idea-reality-mcp MCP server performs a pre-build reality check by scanning GitHub, npm, PyPI, Hacker News, and Stack Overflow. It produces a 0–100 signal and includes evidence, trend detection, and pivot suggestions so an AI agent can decide next steps.
How to check if someone already built your app idea — automatically.
idea-reality-mcp is an MCP server that scans GitHub, npm, PyPI, Hacker News, and Stack Overflow to check if your startup idea already exists. It returns a 0–100 reality score with evidence, trend detection, and pivot suggestions — so your AI agent can decide whether to build, pivot, or kill the idea before writing any code.
When to use this: You're about to start a new project and want to know if similar tools already exist, how competitive the space is, and whether the market is growing or declining.
Project status (August 2026): Maintenance mode. The tool works, stays free & open source, and the hosted API remains up; bug reports are reviewed, but no new features are planned.
Not just checking — building it? After a reality check, open your idea as a public project on AngelRun — ship updates, climb the season, and get seen by angels.
Your AI agent never Googles anything before it starts building.idea_check runs inside your agent — it triggers automatically whether you remember or not.
Google
ChatGPT
idea-reality-mcp
Who runs it
You, manually
You, manually
Your agent, automatically
Output
10 blue links
"Sounds promising!"
Score 0-100 + evidence
Sources
Web pages
None (LLM)
GitHub + HN + npm + PyPI + PH + SO
Price
Free
Paywall
Free & open-source (MIT)
Modes
Mode
Sources
Use case
quick (default)
GitHub + HN
Fast sanity check, < 3 seconds
deep
GitHub + HN + npm + PyPI + Stack Overflow
Full competitive scan
Scoring weights
Source
Quick
Deep
GitHub repos
60%
22%
GitHub stars
20%
9%
Hacker News
20%
14%
npm
—
18%
PyPI
—
13%
Stack Overflow
—
10%
If a source is unavailable, its weight is redistributed automatically — so the deep-mode
weights above are renormalised over the sources that actually answered.
Product Hunt was removed on 2026-07-17. It had carried 14% of the deep-mode weight
since launch and had never returned a single result: the adapter asked for
posts(search: $query), and Product Hunt's API has no text search on posts at all
(Field 'posts' doesn't accept argument 'search'). Its weight is now redistributed to
sources that answer. If you need it back, it needs a real search surface — not a token.
{"reality_signal":72,"duplicate_likelihood":"high","trend":"accelerating","sub_scores":{"market_momentum":73},"evidence":[{"source":"github","type":"repo_count","query":"...","count":342},{"source":"github","type":"max_stars","query":"...","count":15000},{"source":"hackernews","type":"mention_count","query":"...","count":18},{"source":"npm","type":"package_count","query":"...","count":56},{"source":"pypi","type":"package_count","query":"...","count":23},{"source":"stackoverflow","type":"question_count","query":"...","count":120}],"top_similars":[{"name":"user/repo","url":"https://github.com/...","stars":15000,"description":"..."}],"pivot_hints":["High competition. Consider a niche differentiator...","The leading project may have gaps in..."]}
export GITHUB_TOKEN=ghp_... # Higher GitHub API rate limits
PRODUCTHUNT_TOKEN no longer does anything — the source is disabled and ignores it.
Setting it used to be worse than useless: it un-skipped a source whose query the API
rejects, so it reported "0 competitors on Product Hunt" into 14% of the deep score.
Auto-trigger: Add one line to your CLAUDE.md, .cursorrules, or .github/copilot-instructions.md:
code
When starting a new project, use the idea_check MCP tool to check if similar projects already exist.
Roadmap
v0.1 — GitHub + HN search, basic scoring
v0.2 — Deep mode (npm, PyPI, Product Hunt), keyword extraction
v0.3 — 3-stage keyword pipeline, Chinese term mappings, LLM-powered search
