API Protect Micro API Firewall

In previous tutorials, we have covered static analysis with the API security audit, dynamic testing with conformance scan – now it’s time to discuss protection. The Protection function is real-time protection of live APIs.

Protection Overview

You put our API firewall in the line of traffic. It’s an extremely efficient piece of software that we ship as a docker image. It’s been written in C, is highly optimized, less than 20 megabytes in size and has a sub-millisecond overhead.

When put in the line of traffic, our API Firewall uses your secure OpenAPI definition as an allowlist and policies. Essentially, it enforces the contract on all the API calls and all the responses (data coming in, data going out). Therefore, no call with get to your code if it’s outside of your contract, and no response will get sent back if it’s not expected.

To enable Protection, first click on Protect API.

protect-api (Custom)

Generating a Token

Next step is to generate a token. (1) Click on Protection Tokens > (2) Create Token > (3) Enter a name > (4) Click Generate Token. (screen shot of naming).

You then copy the token. Once you copy the token and close out the window there is no way to get the token for security reasons.

Deployment Docs

You will then need to configure your network to pass all the API calls and responses through the 42Crunch API Firewall. Click on Deploy Your APIs to follow the proper documentation related to your current deployment.

Navigating the Report

All actual security issues are scored based on the risk involved. The greater the risk, the higher the score (priority). You can filter issues by priority or category, or view all found issues as a list. You can also search for specific issues both in ‘All Issues’ and in each individual category.

You can immediately start fixing issues from the priority list, or click into individual issues and remediate from there. Clicking on Go to Issue takes you to the place in your code where the issue occurs and shows you a description and remediation recommendations.

Watch the 42Crunch API Firewall in Action

Check out the demo below to see our API micro-firewall in action!

Latest Resources


Something Old, Something New – OWASP API Security Top 10 in 2023

42Crunch’s Colin Domoney takes a look at the new OWASP API Security 2023 listing, identifying which vulnerabilities are new, which have not changed and which have been removed.


Analyst Report: Review of Partnership Between 42Crunch and Microsoft

By Dr. Edward Amoroso | November 29, 2023

This  analyst report prepared by Dr. Edward Amoroso, CEO of Tag Infosphere Inc, offers a review of the recently announced partnership between cybersecurity vendor 42Crunch and Microsoft. Introduction The recently announced partnership between 42Crunch and Microsoft, integrating 42Crunch’s API security solutions 1 with Microsoft Defender for Cloud 2, […]


APIs are the core building block of every enterprise’s digital strategy, yet they are also the number one attack surface for hackers. 42Crunch makes developers’ and security practitioners' lives easier by protecting APIs, with a platform that automates security into the API development pipeline and gives full oversight of security policy enforcement at every stage of the API lifecycle.

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Developer-first solution for delivering API security as code.