For Developers APIs, SDKs & security tools
Build security checks with versioned APIs, typed SDKs, an interactive playground, and a free tier.
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Key features. Everything you need to protect your infrastructure and users.
REST API
Simple, well-documented REST endpoints.
API Playground
Try the API without writing code.
Comprehensive Docs
Detailed guides, examples, and tutorials.
Open Source
The TypeScript SDK is open source on GitHub.
Fast & Reliable
Sub-100ms responses with high availability.
Use cases. How security teams use this tool.
App Security
Add threat checking to your applications.
CI/CD Integration
Scan dependencies and URLs in pipelines.
Security Tools
Build security tools with our data.
Research
Analyze threats for security research.
Build Secure Applications with Threat Intelligence
Modern applications need security built in from the start. Whether you're building a web application, mobile app, or backend service, integrating threat intelligence helps protect your users from malicious content. Our APIs make it easy to check URLs before redirecting users, verify domain reputation before displaying content, or block malicious IPs before they can exploit your systems. A few lines of code can dramatically improve your application's security posture.
Developer-First API Design
We built our API with developers in mind: - **RESTful Design**: Standard REST conventions that work exactly as you'd expect - **Consistent Responses**: Predictable JSON response formats across all endpoints - **Comprehensive Errors**: Clear error messages with specific guidance - **Versioned API**: Breaking changes only in major versions, with long deprecation windows - **Rate Limit Headers**: Know your quota status with every response - **Request IDs**: Every request gets a unique ID for debugging and support No surprises, no gotchas - just a clean API that's easy to integrate.
Official SDK and Client Libraries
Don't write boilerplate - use the published client, or call REST directly: - **TypeScript SDK**: `@ismalicious/sdk` on npm. Types included, CommonJS and ESM. - **Python, Go, Rust**: no published packages yet. Call `GET /check` with `X-API-KEY`, or generate a client from the OpenAPI spec. The TypeScript SDK is open source on GitHub.
Free Tier for Development and Testing
Get started without commitment: - **30 Free Requests/Month**: Enough for development, testing, and initial evaluation - **No Credit Card Required**: Sign up with just an email address - **Full API Access**: The free tier includes all endpoints, not a limited subset - **Generous Rate Limits**: 10 requests/second - plenty for development workflows - **Forever Free**: Not a trial - the free tier doesn't expire When you're ready to scale, Pro starts at €99/month with flexible usage-based pricing for production workflows.
Frequently asked questions.
Is the free tier really free?
What SDKs are available?
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Can I use it in production?
Related articles. Learn more from our security research blog.
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Join thousands of security teams using isMalicious to protect their infrastructure.
No credit card required · Free API key