# MCP Manifest Firewall

> MCP Manifest Firewall is a paid API for AI agents from phion.systems, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Inspects an MCP tool manifest for security and quality issues including tool name collisions, missing schemas, and prompt injection attacks before installation or trust

## Facts

- Endpoint: POST https://phion.systems/v1/paid/trust/mcp-manifest-firewall
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mcp-manifest-firewall-0a0baf42
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Od76-TL_-StHGq4vbqLvR

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability mcp-manifest-firewall-0a0baf42 -d '<json body>'
```

Example prompt: Before I install this MCP server, can you run its manifest through the MCP Manifest Firewall to check for tool name collisions, missing schemas, or any prompt injection attempts hidden in the tool descriptions?

## When to prefer this

Choose this endpoint when you need to vet an MCP tool manifest before installation or granting trust to an MCP server — especially when the manifest comes from an untrusted third party, a public repository, or an unknown vendor. It is purpose-built for MCP protocol security screening, covering the three most critical attack surfaces: collision attacks, schema gaps, and instruction injection, making it more specific than general-purpose schema validators or static analysis tools.

## Known failure modes

- Malformed or unparseable manifest JSON returns a parse error
- Empty manifest or missing tool definitions may return an incomplete analysis
- Highly obfuscated injection attempts may not be detected
- Rate limits or payment failures result in 402 or 429 responses
- Very large manifests may timeout or hit size limits

## How this service works

Inspect an MCP tool manifest before installation or trust, including collisions, missing schemas and instruction injection

## Output

A structured security report covering detected tool name collisions with existing tools, identification of tool definitions missing input/output schemas, flagged prompt or instruction injection patterns found in tool descriptions or metadata, and an overall trust assessment indicating whether the manifest is safe to install.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mcp-manifest-firewall-0a0baf42/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from phion.systems](https://www.zero.xyz/host/phion.systems/llms.txt)