fennecBLOCK
AI-native developer observability MCP (Model Context Protocol) server that gives AI agents full-stack visibility into your development environment — browser, terminal, and processes — all in one unified interface.
Overview
From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.
Fennec 🦊
Ears everywhere in your stack.
AI-native developer observability MCP — browser, terminal, and processes, all in one.
What is Fennec?
Fennec is an MCP (Model Context Protocol) server that bridges the gap between AI agents and your development environment. Instead of you copy-pasting errors between terminal, browser, and AI, Fennec gives your AI agent direct access to all three simultaneously — and lets it run and supervise your apps, not just observe them.
The Problem It Solves
When a developer asks an AI agent "why is my login broken?", the agent is essentially blind:
What agent sees: What developer sees: ───────────────── ────────────────────────────────── "I can't access Browser
9e176011f7e9OBSERVED · 2026-10-11Connect
Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control. Replace the environment placeholders with a token scoped to the least it needs.
claude mcp add fennec-core --env FENNEC_VAULT_KEY=${FENNEC_VAULT_KEY} -- npx -y @plumpslabs/[email protected]{
"mcpServers": {
"fennec-core": {
"command": "npx",
"args": [
"-y",
"@plumpslabs/[email protected]"
],
"env": {
"FENNEC_VAULT_KEY": "${FENNEC_VAULT_KEY}"
}
}
}
}Exposed tools (19)
17 read · 1 write · 1 destructive. Blast radius: 1 tool can delete or overwrite — an agent that can be talked into calling a tool can be talked into calling this one.
| Tool | Risk | Description |
|---|---|---|
Context | read | |
Debug | read | |
Disabled | read | |
Exec | write | |
Failing | read | |
Other | read | |
Retry | read | |
Simple | read | |
Skip | read | |
Test | read | |
WF1 | read | |
WF2 | read | |
browser | read | Browser automation and DevTools — navigation, interaction, DOM, console, network, storage, auth, tabs, diagnostic |
mobile | read | Mobile device management via ADB — device detection, tap, type, swipe, pinch, logcat, screenshot, UI hierarchy dump, app management. Integrated with EventBus for cross-layer correlation. |
process | destructive | Process management and terminal monitoring — spawn, kill, attach, pipe watching, log filtering |
test | read | |
test_empty | read | An empty tool |
test_hello | read | A test tool |
test_tool | read | Test tool |
Trust audit
BLOCKgrade D · trust 69/100 Do not install this without reading the findings. The audit found something that could harm you or your machine.
| Layer | What it checks | Result |
|---|---|---|
| L0 | Provenance & inventory | PASS |
| L1 | Static analysis of the code | FAIL |
| L2 | Instruction surface (what it tells the agent) | PASS |
| L3 | Class-specific surface | WARN |
| L4 | Behavioural (sandbox) | SKIPPED |
What the source does
- Filesystem
- declared (2 observation(s))
- Network
- declared (7 observation(s))
- Shell
- declared (6 observation(s))
- Dependencies
- not all pinned
- Secrets in source
- none-found
Findings (21)
const parsed = yaml.load(raw) as DevConfig;
return `http://127.0.0.1:${port}${healthCheck}`;process
.prettierignore
readFileSync(new URL('../../package.json', import.meta.url), 'utf-8'),const CLI = resolve(__dirname, '../../dist/index.js');
} from '../../src/commands/assistant.js';
import { VERSION } from '../../src/utils/banner.js';const CLI = resolve(__dirname, '../../dist/index.js');
With `--sse`, Fennec starts an HTTP+SSE endpoint (default `http://127.0.0.1:3333/sse`).
`require('http').get('http://127.0.0.1:${port}',r=>process.exit(0)).on('error',()=>process.exit(1))`,`require('http').get('http://127.0.0.1:${extPort}',r=>process.exit(0)).on('error',()=>process.exit(1))`,`require('http').get('http://127.0.0.1:${extPort}',r=>process.exit(0)).on('error',()=>process.exit(1))`,prettier, typescript
js-yaml, cli-table3, picocolors, @types/js-yaml, @types/node, tsup, typescript, vitest
@modelcontextprotocol/sdk, js-yaml, zod, zod-to-json-schema, @types/js-yaml, @types/node, playwright, tsup
smart_fill_form({ fields: { "email": "[email protected]", "password": "secret" }, submitAfter: true })"text": "{\"success\":true,\"data\":{\"page\":{\"url\":\"http://localhost:3000/login\",\"title\":\"Login Page\",\"readyState\":\"complete\"},\"consoleErrors\":[\"TypeError: Cannot read properties of u"text": "{\"success\":true,\"data\":{\"browser\":{\"url\":\"http://localhost:3000/login\",\"title\":\"Login Page\",\"consoleErrors\":[\"TypeError: Cannot read properties of undefined (reading 'token')"text": "{\"success\":true,\"data\":{\"request\":{\"url\":\"https://api.example.com/api/auth/token\",\"method\":\"POST\",\"headers\":{\"content-type\":\"application/json\"},\"postData\":\"{\\\"email\\| **🗄️ Database** | dbTui sidecar (Go binary) | Database observation: PostgreSQL, MySQL, SQLite — schema inspection, read-only queries, health checks, credential management via OS keychai
Gates applied: no_behavioural_pass.
9e176011f7e9full audit observations/trust-audit/mcp-server/plumpslabs__fennec.json · Report an issue / request a re-scanAudit history
Every audit this server has had. A grade with a past is a grade somebody is still checking.
| Date | Source | Verdict | Grade | Score | Change |
|---|---|---|---|---|---|
| 2026-10-11 | 9e176011f7e9 | BLOCK | D | 69 | first audit |
Questions
What is the fennec MCP server?
AI-native developer observability MCP (Model Context Protocol) server that gives AI agents full-stack visibility into your development environment — browser, terminal, and processes — all in one unified interface.
What tools does fennec expose?
19 in total: 17 read-only, 1 that write, and 1 that can delete or overwrite (process). Every one is listed on this page with its risk.
Is fennec safe to connect to an agent?
No — not without reading the findings first. The audit graded it D (69/100) and found 1 critical or high issue in the source. Each one is listed on this page with the file and line it is on. Separately from the audit: 1 of its tools can destroy data, so scope the token you give it to what you actually need.
What credentials does fennec need?
It reads FENNEC_VAULT_KEY from the environment. Give it a token scoped to the least it needs — an agent that can be talked into calling a tool can be talked into calling it with your credentials.
How does fennec run?
It speaks sse and stdio, so it runs as a local process your client starts. It is published on npm as @plumpslabs/fennec-core at 1.17.1.
How current is this page?
The grade is for one exact copy of the source (9e176011f7e9), read on 2026-10-11. The repository is watched and re-audited when it changes.