extenshi.io
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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

408,058
Extensions tracked
632,294
Versions & updates tracked
363,619
User reviews collected
Chrome Web StoreFirefox Add-onsEdge Add-ons
Browser stores covered
Tool examples

What you get

Data from 408K+ 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."

>_

"Look up this extension by its store link and explain its high-severity findings."

>_

"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.

Connect over OAuth

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. The connector supports catalog research, project and hosted-page tools, and Pay application management with the permissions you grant. Use the local setup above to scan a build. 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

Search and extension details cost one read each. A full security report with get_security costs three reads.

$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.

Find security issues before submission

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

Automate your pre-publish scansRead the docs

Start with three security scans included with your account.