Preflight (All the Possibles)

What Preflight (All the Possibles) does

Preflight (All the Possibles) provides security checks for systems and content that an AI agent may connect to, read, install, or trust. It focuses on risk signals that ordinary schema validation or a basic install review can miss, including unauthenticated MCP transports, overly broad capabilities, hidden instructions, obfuscated payloads, and suspicious output patterns.

The service exposes four MCP tools. scan_mcp_server evaluates a reachable server URL or accepts a manifest containing tool definitions when the target cannot be accessed over HTTP. scan_content examines either a fetched URL or text supplied directly. scan_extension covers VS Code extensions and Claude Skills. check_output reviews structured data before an agent returns it or acts on it.

How it works

The remote MCP endpoint is available at https://preflight.allthepossibles.com/mcp over Streamable HTTP. A client can connect to that endpoint and invoke the scanning tools through MCP. A separate REST API is also available for applications that do not use MCP.

Server checks look for transport authentication gaps, capabilities that expose filesystem, shell, or credential access without scoping, and known-bad signatures. Content checks identify invisible Unicode and obfuscated payloads. On the Pro tier, semantic analysis also looks for prompt-injection language directed at the model rather than the human reader.

Extension analysis differs by artifact type. For VS Code extensions, the service considers publisher domain verification alongside install count and checks descriptions for known-bad signatures. Claude Skill checks inspect the SKILL.md body, tool-grant frontmatter, inline shell execution, and bundled scripts for credential-exfiltration patterns. Pro analysis adds semantic prompt-injection detection for the skill body.

Output checks cover invalid JSON, placeholder values such as TBD, N/A, or unknown where a substantive answer is expected, repeated byte-identical array items, and missing or empty expected fields.

Setup and configuration

Connect an MCP-compatible client to https://preflight.allthepossibles.com/mcp using Streamable HTTP. The service offers a free tier without signup. Pro semantic scanning is enabled when a Pro API key is supplied as an Authorization: Bearer header. For scan_mcp_server, provide either a live server URL or a tool manifest; for scan_content, provide a URL or raw text.

Tools and capabilities

• scan_mcp_server: Review MCP transport authentication, capability scope, and known-bad signatures.
• scan_content: Detect invisible Unicode, obfuscation, and Pro semantic prompt-injection signals in text or fetched pages.
• scan_extension: Assess VS Code extensions and Claude Skills, including skill instructions, grants, shell commands, and bundled scripts.
• check_output: Find malformed or suspicious structured output before it is trusted.

Limitations and notes

Semantic prompt-injection analysis requires the Pro tier and a Pro API key. A server that is not reachable over HTTP must be represented with a manifest for scan_mcp_server. check_output complements schema validation; valid structure alone does not establish that the answer is meaningful or safe to use.