BlowbackBLOCK
MCP Server for Frontend dev environment (formerly known as vite-mcp-server)
Overview
From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.
Vite MCP Server is now Blowback Blowback aims to support various FE development servers, not only Vite
A Model Context Protocol (MCP) server that integrates FE development servers with AI tools like Claude Desktop and Cursor.
How to Use
Command (Claude Code):
claude mcp add blowback -s project -e PROJECT_ROOT=/path/to/your/project -- npx -y blowback-context
Or use json configuration:
- Claude Code:
{PROJECT_ROOT}/.mcp.json - Cursor:
{PROJECT_ROOT}/.cursor/mcp.json
{
"mcpServers": {
"blowback": {
"command": "npx",
"args": ["-y", "blowback-context"],
"env": {
"PROJECT_ROOT": "/path/to/your/project"
}
}
}
}Environment Variables
PROJECT_ROOT: Project root path (optional, defaults to current working directory)ENABLE_BASE64: Include base64 encoded images in tool responses (default: false / affects token usage and context window when enabled)
Key Features
- Integration of local development server with MCP server
- Browser console log capture and transmission via MCP
- Checkpoint-based log management
- Screenshot capture and SQLite database management
- HMR (Hot Module Replacement) event monitoring
- Browser automation and element inspection
init Prompt
The init prompt provides guidance to AI assistants on how to effectively use the following features:
Cursor Chat does not support MCP prompt functionality, so this feature is not available. (Claude Code recommended) If needed, manually input the following prompt:
You can use checkpoint features by inserting `` into the head to create a named snapshot of the current state. The data-id attribute is a unique identifier for the checkpoint. Console logs generated in the browser while a checkpoint is active are tagged with the checkpoint ID and can be queried individually. Note: In some development environments, hot reload is triggered when files ar
ae0654243abfOBSERVED · 2026-10-09Connect
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.
claude mcp add blowback-context -- npx -y [email protected]
{
"mcpServers": {
"blowback-context": {
"command": "npx",
"args": [
"-y",
"[email protected]"
]
}
}
}Exposed tools (16)
14 read · 2 write · 0 destructive.
| Tool | Risk | Description |
|---|---|---|
browser-evaluate | read | Evaluates JavaScript code directly in the browser context and returns the result. Supports expressions, function strings, and complex code with automatic execution handling. Can target the entire page or work with element handles for precise DOM manipulation. Examples: - Simple expression: |
capture-screenshot | read | Captures a screenshot of the current page or a specific element. Stores the screenshot in the MCP resource system and returns a resource URI. If ENABLE_BASE64 environment variable is set to |
close-browser | read | Closes a specific browser instance |
execute-browser-commands | write | |
get-console-logs | read | Retrieves console logs from the development server |
get-context-info | read | Gets detailed information about a specific browser instance |
get-context-stats | read | Gets usage statistics for browsers |
get-element-dimensions | read | Retrieves dimension and position information of a specific element |
get-element-html | read | Retrieves the HTML content of a specific element and its children with optional depth control |
get-element-properties | read | Retrieves properties and state information of a specific element |
get-element-styles | read | Retrieves style information of a specific element |
get-hmr-events | read | Retrieves recent HMR events |
how-to-use | read | Description of how to use the server |
list-browsers | read | Lists all active browser instances |
monitor-network | read | Monitors network requests in the browser for a specified duration |
start-browser | write | Creates a new browser context with an auto-generated unique ID |
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 | PASS |
| L4 | Behavioural (sandbox) | SKIPPED |
What the source does
- Filesystem
- none-observed
- Network
- declared (3 observation(s))
- Shell
- declared (1 observation(s))
- Dependencies
- not all pinned
- Secrets in source
- none-found
Findings (5)
const func = eval(`(${fn})`);cdpEndpoint = `http://127.0.0.1:${cdpPort}`;.eslintignore
@modelcontextprotocol/sdk, node-sqlite3-wasm, playwright, ws, zod, @changesets/cli, @types/node, @types/ws
Gates applied: no_behavioural_pass, no_license.
ae0654243abffull audit observations/trust-audit/mcp-server/esnark__blowback.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 |
|---|---|---|---|---|---|
| 2026-10-09 | ae0654243abf | BLOCK | D | 69 | first audit |
Questions
What is the Blowback MCP server?
MCP Server for Frontend dev environment (formerly known as vite-mcp-server)
What tools does Blowback expose?
16 in total: 14 read-only, 2 that write, and 0 that can delete or overwrite. Every one is listed on this page with its risk.
Is Blowback 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.
What credentials does Blowback need?
No credential environment variables were found in its source, so it appears to need none.
How does Blowback run?
It speaks stdio, so it runs as a local process your client starts. It is published on npm as blowback-context at 1.1.1.
How current is this page?
The grade is for one exact copy of the source (ae0654243abf), read on 2026-10-09. The repository is watched and re-audited when it changes.