Snyk Agent Scan

Discover and scan agent components on your machine for prompt injections
and vulnerabilities (including agents, MCP servers, skills).

> **NEW** Read our [technical report on the emerging threats of the agent skill eco-system](.github/reports/skills-report.pdf) published together with Agent Scan 0.4, which adds support for scanning agent skills.

Agent Scan helps you keep an inventory of all your installed agent components (harnesses, MCP servers, skills) and scans them for common threats like prompt injections, sensitive data handling, or malware payloads hidden in natural language. ## Highlights - Auto-discover MCP configurations, agent tools, skills - Scanning of Claude, Cursor, Windsurf, Gemini CLI, and other agents. - Detects [15+ distinct security risks](docs/issue-codes.md) across MCP servers and agent skills: - MCP: [Prompt Injection](docs/issue-codes.md#E001), [Tool Poisoning](docs/issue-codes.md#E003), [Tool Shadowing](docs/issue-codes.md#E002), [Toxic Flows](docs/issue-codes.md#TF001), [Rug Pull](docs/issue-codes.md#W005) - Skills: [Prompt Injection](docs/issue-codes.md#E004), [Malware Payloads](docs/issue-codes.md#E006), [Untrusted Content](docs/issue-codes.md#W011), [Credential Handling](docs/issue-codes.md#W007), [Hardcoded Secrets](docs/issue-codes.md#W008) ## Quick Start To get started: 1. **Sign up at [Snyk](https://snyk.io)** and get an API token from [https://app.snyk.io/account](https://app.snyk.io/account) (API Token → KEY → click to show). 2. **Set the token as an environment variable** before running any scan: ```bash export SNYK_TOKEN=your-api-token-here ``` 3. Have [uv](https://docs.astral.sh/uv/getting-started/installation/) installed on your system. ### Scanning To run a full scan of your machine (auto-discovers agents, MCP servers, skills), run: ```bash uvx snyk-agent-scan@latest --skills ``` This will scan for security vulnerabilities in servers, skills, tools, prompts, and resources. It will automatically discover a variety of agent configurations, including Claude Code/Desktop, Cursor, Gemini CLI, and Windsurf. Omit `--skills` to skip skill analysis. You can also scan particular configuration files: ```bash # scan mcp configurations uvx snyk-agent-scan@latest ~/.vscode/mcp.json # scan a single agent skill uvx snyk-agent-scan@latest --skills ~/path/to/my/SKILL.md # scan all claude skills uvx snyk-agent-scan@latest --skills ~/.claude/skills ``` #### Example Run [](https://asciinema.org/a/716858) ## Scanner Capabilities Agent Scan is a security scanning tool to both scan and inspect the supply chain of agent components on your machine. It scans for common security vulnerabilities like prompt injections, tool poisoning, toxic flows, or vulnerabilities in agent skills. Agent Scan operates in two main modes which can be used jointly or separately: 1. **Scan Mode**: The CLI command `snyk-agent-scan` scans the current machine for agents and agent components such as skills and MCP servers. Upon completion, it will output a comprehensive report for the user to review. 2. **Background Mode** (MDM, Crowdstrike). Agent Scan scans the machine in regular intervals in the background, and reports the results to a [Snyk Evo](https://evo.ai.snyk.io) instance. This can be used by security teams to monitor the company-wide agent supply chain in a central location. To set this up, please [contact us](https://evo.ai.snyk.io/#contact-us). ## How It Works ### Scanning Agent Scan searches through your local agent's configuration files to find agents, skills, and MCP servers. For MCP, it connects to servers and retrieves tool descriptions. It then validates the components, both with local checks and by invoking the Agent Scan API. For this, skills, agent applications, tool names, and descriptions are shared with Snyk. By using Agent Scan, you agree to the Snyk [terms of use for Agent Scan](./TERMS.md). A unique, persistent, and anonymous ID is assigned to your scans for analysis. You can opt out of sending this information using the `--opt-out` flag. Agent Scan does not store or log any usage data, i.e. the contents and results of your MCP tool calls. ## CLI Parameters Agent Scan provides the following commands: ``` snyk-agent-scan - Security scanner for agents, MCP servers, and skills ``` ### Common Options These options are available for all commands: ``` --storage-file FILE Path to store scan results and scanner state (default: ~/.mcp-scan) --base-url URL Base URL for the verification server --verbose Enable detailed logging output --print-errors Show error details and tracebacks --full-toxic-flows Show all tools that could take part in toxic flow. By default only the top 3 are shown. --json Output results in JSON format instead of rich text ``` ### Commands #### scan (default) Scan MCP configurations for security vulnerabilities in tools, prompts, and resources. ``` snyk-agent-scan scan [CONFIG_FILE...] ``` Options: ``` --checks-per-server NUM Number of checks to perform on each server (default: 1) --server-timeout SECONDS Seconds to wait before timing out server connections (default: 10) --suppress-mcpserver-io BOOL Suppress stdout/stderr from MCP servers (default: True) --skills Autodetects and analyzes skills --skills PATH_TO_SKILL_MD_FILE Analyzes the specific skill --skills PATHS_TO_DIRECTORY Recursively detects and analyzes all skills in the directory ``` #### inspect Print descriptions of tools, prompts, and resources without verification. ``` snyk-agent-scan inspect [CONFIG_FILE...] ``` Options: ``` --server-timeout SECONDS Seconds to wait before timing out server connections (default: 10) --suppress-mcpserver-io BOOL Suppress stdout/stderr from MCP servers (default: True) ``` #### help Display detailed help information and examples. ```bash snyk-agent-scan help ``` ### Examples ```bash # Scan all known MCP configs snyk-agent-scan # Scan a specific config file snyk-agent-scan ~/custom/config.json # Just inspect tools without verification snyk-agent-scan inspect ``` ## Demo This repository includes a vulnerable MCP server that can demonstrate Model Context Protocol security issues that Agent Scan finds. How to demo MCP security issues? 1. Clone this repository 2. Create an `mcp.json` config file in the cloned git repository root directory with the following contents: ```jsonc { "mcpServers": { "Demo MCP Server": { "type": "stdio", "command": "uv", "args": ["run", "mcp", "run", "demoserver/server.py"], }, }, } ``` 3. Run Agent Scan: `uvx --python 3.13 snyk-agent-scan@latest scan --full-toxic-flows mcp.json` Note: if you place the `mcp.json` configuration filepath elsewhere then adjust the `args` path inside the MCP server configuration to reflect the path to the MCP Server (`demoserver/server.py`) as well as the `uvx` command that runs Agent Scan with the correct filepath to `mcp.json`. ## Agent Scan is closed to contributions Agent Scan does not accept external contributions at this time. We welcome suggestions, bug reports, or feature requests as GitHub issues. ## Development Setup To run Agent Scan from source, follow these steps: ```bash uv run pip install -e . uv run -m src.agent_scan.cli ``` ## Including Agent Scan results in your own project / registry If you want to include Agent Scan results in your own project or registry, please [reach out](https://evo.ai.snyk.io/#contact-us). There are designated APIs for this purpose. Using the standard Agent Scan API for large scale scanning is considered abuse and will result in your account being blocked. ## Documentation - [Scanning](docs/scanning.md) — How scanning works, CLI parameters, and usage examples. - [Issue Codes](docs/issue-codes.md) — Reference for all security issues detected by Agent Scan. ## Further Reading - [Introducing MCP-Scan](https://invariantlabs.ai/blog/introducing-mcp-scan) - [MCP Security Notification Tool Poisoning Attacks](https://invariantlabs.ai/blog/mcp-security-notification-tool-poisoning-attacks) - [WhatsApp MCP Exploited](https://invariantlabs.ai/blog/whatsapp-mcp-exploited) - [MCP Prompt Injection](https://simonwillison.net/2025/Apr/9/mcp-prompt-injection/) - [Toxic Flow Analysis](https://invariantlabs.ai/blog/toxic-flow-analysis) - [Skills Report](.github/reports/skills-report.pdf) ## Changelog See [CHANGELOG.md](CHANGELOG.md).