MarketNow Registry / Developer Tools / defender

defender

Open source prompt injection protection for Agents calling tools (via MCP, CLI or direct function calling). Detect and defend against prompt injection attacks. 22MB, CPU-only, < 10ms latency.

Developer Tools v1.0.0 by StackOneHQ

Trust score

40/100

Install risk

Runs registry code

Source

github

Indexed

2026-09-10

Install

$ npx -y defender

Installing via npx/uvx/npm install executes arbitrary code from the public registry on your machine. This is the install-risk semantic of the MarketNow catalog — verify the publisher before running it.

How MarketNow scored this

Sentinel Index Heuristics — a security-first estimate from public signals:

Package age and release activity (stale repositories lose points)
Verified adoption: registry downloads or GitHub stars, not follower counts
Typosquat distance against the 150 most-installed MCP packages
Injection markers scanned in the package description

Heuristic, not a guarantee. For verified agent credentials and revocation, see the MarketNow Trust API.

What is defender?

Open source prompt injection protection for Agents calling tools (via MCP, CLI or direct function calling). Detect and defend against prompt injection attacks. 22MB, CPU-only, < 10ms latency. Indexed by MarketNow with trust 40/100 (Runs registry code).

How do I install it?

Run $ npx -y defender Installing via npx/uvx/npm install executes arbitrary code from the public registry on your machine. This is the install-risk semantic of the MarketNow catalog — verify the publisher before running it.

What does the trust score mean?

Security-first heuristic over public signals (age, adoption, typosquat distance, injection markers). It is not a popularity ranking and not a guarantee of safety. defender scores 40/100.