extenshi.io
For developers

The MCP server for browser extension data,inside your AI tools

Cross-store search across Chrome, Firefox and Edge, security findings, market stats, and pre-publish Chrome Web Store scanning — exposed as tools in Claude Code, Cursor, and any MCP client. It serves extension data, not browser automation.

Get your API key — freeSee setup
No credit card10 free reads3 free scansRuns locally over stdio
bash · claude mcp add
# run in your project root
claude mcp add extenshi \
  --env EXTENSHI_API_KEY=ek_… \
  -- npx -y @extenshi/mcp@latest

Comprehensive extension data

We track and analyze the browser extension ecosystem

373,262
Extensions tracked
599,334
Versions & updates tracked
296,924
User reviews collected
Chrome Web StoreFirefox Add-onsEdge Add-ons
Browser stores covered
Six tools

What you get

Data from 373K+ tracked extensions across Chrome, Firefox and Edge — one API key away.

Search the cross-store catalog

search_extensions()

Inspect any extension

get_extension(id / store id)

Read security findings

get_security(id / store id)

Read market stats

market_overview()

Check remaining credits

get_credit_balance()

Search the docs & CLI reference

search_docs()

Scan before you publish

scan_extension(.zip / .crx / .xpi) — live per-scanner progress
3 free, one-time
No API juggling

Ask in plain language

>_

"Find the top 10 Chrome password managers and compare the permissions they request."

>_

"Show me the security findings for Grammarly and explain the high-severity ones."

>_

"Scan ./dist/my-extension.zip before I submit it to the Chrome Web Store."

>_

"How do I scan in CI and gate my release with the Extenshi CLI?"

>_

"Which screenshot extensions carry the highest risk score right now?"

Two minutes

Set up in three steps

1

Create an account

Sign up at auth.extenshi.io/signup

2

Copy your API key

Ready at dojo.extenshi.io/api-keys — copy it

3

Add it to your client

Pick your client above and set EXTENSHI_API_KEY

Get your API key — free

Works with Claude Code, Claude Desktop, Cursor, Codex and VS Code.

Prefer no install? Add the remote connector

On Claude.ai, Claude Desktop or Cowork, add Extenshi as a custom connector by URL — https://mcp.extenshi.io/mcp — and sign in with your Extenshi account. No API key, nothing to install. It exposes the search & research tools; use the local setup above when you need to scan or publish. Connector docs →

Pricing

Free to start, pay as you go

Start on the one-time free allowance, then pay as you go with prepaid packs that never expire — buy scans and reads separately.

Free

$0one-time

A one-time free allowance to try it in your client — no card.

  • 10 reads
  • 3 scans
Start free
Scan packs

Prepaid scans, never expire

One scan = one pre-publish security scan. Top up anytime.

$10$1.00 / scan
  • 10scans

Base rate

Best value
$80$0.80 / scan
  • 100scans

20% cheaper per scan

$500$0.50 / scan
  • 1,000scans

50% cheaper per scan

Read packs

Prepaid reads, never expire

One read = one GET request to our API — search, an extension's details, security findings or market stats.

$10$0.10 / read
  • 100reads

Base rate

Best value
$80$0.08 / read
  • 1,000reads

20% cheaper per read

$500$0.05 / read
  • 10,000reads

50% cheaper per read

Buy credit packs

Scans and reads are separate, prepaid, and never expire. The free allowance is a one-time grant — no credit card to start.

Ship to the stores without the takedown risk

Wire Extenshi into your build so every release is scanned before it reaches the review queue.

Automate your pre-publish scansRead the docs

Catch findings before reviewers do — and keep your extensions live.