Open-Source Security · microsoft

ApplicationInspector

Application Inspector is a Microsoft-built static analysis tool that scans source code to identify what software does by detecting library calls, APIs, encryption, and framework usage across 12+ programming languages. It uses 400+ rule patterns to characterize code features and security-relevant behaviors without making pass/fail judgments.

Talk to DEV.co Discuss Implementation

Source: GitHub — github.com/microsoft/ApplicationInspector

4.4k

GitHub stars

366

Forks

Primary language

MIT

License (OSI-approved)

Key facts

Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.

Field	Value
Repository	microsoft/ApplicationInspector
Owner	microsoft
Primary language	C#
License	MIT — OSI-approved
Stars	4.4k
Forks	366
Open issues	27
Latest release	v1.9.55 (2026-01-22)
Last updated	2026-06-24
Source	https://github.com/microsoft/ApplicationInspector

What ApplicationInspector is

A C# command-line and NuGet-based static analyzer that employs a JSON rules engine to surface code characteristics through pattern matching and regex detection. It generates HTML, JSON, SARIF, and Markdown reports and supports mixed-language projects with file exclusion via glob patterns.

Quickstart

Get the ApplicationInspector source

Clone the repository and explore it locally.

terminalbash

1git clone https://github.com/microsoft/ApplicationInspector.git2cd ApplicationInspector3# follow the project's README for install & configuration

Need it deployed, integrated, or customized instead? DEV.co ships production installs.

Best use cases

Third-party component assessment

Quickly understand what an OSS dependency actually does—cryptography methods, cloud API calls, shell operations—before integration, reducing reliance on limited documentation.

Supply chain security scanning

Detect version-to-version feature deltas and identify injection of unexpected functionality as part of component vetting or pre-deployment scanning pipelines.

Build-time compliance automation

Embed in CI/CD to enforce organizational policies (e.g., only approved crypto, no hardcoded credentials) and generate metadata inventories for enterprise software catalogs.

Implementation considerations

Install .NET 6.0 SDK or use platform-specific binaries (Windows, Linux, macOS); global NuGet tool installation recommended for CLI workflows.
Baseline analysis takes seconds to minutes depending on codebase size; performance on multi-million-line repos requires profiling and potential rule subsetting.
Default output is HTML; JSON/SARIF/Markdown formats available for CI integration; consider post-processing reports for policy enforcement.
Rules are versioned with releases; evaluate rule currency for your compliance or security baseline requirements, especially for emerging frameworks or languages.
Multi-language projects are supported, but analyze accuracy varies by language maturity; test on representative samples before production rollout.

When to avoid it — and what to weigh

Need deep vulnerability detection — Application Inspector characterizes features; it does not identify CVEs, buffer overflows, or logic flaws. Use alongside traditional SAST/SCA tools for security scanning.
Require real-time cloud integration — This is a local, offline analysis tool. No built-in API upload, SaaS dashboard, or continuous monitoring; suitable for on-premises and airgapped environments only.
Minimal runtime dependencies — .NET 6.0+ runtime is mandatory for the CLI tool. If your infrastructure cannot support .NET or has strict dependency constraints, consider compiled language alternatives.
Need industry-standard rule customization UI — Custom rules require JSON editing and manual syntax verification. There is no visual rule builder; teams must understand the rule schema and test via verifyrules command.

License & commercial use

MIT License (permissive, OSI-approved). Source code, binaries, and library packages are all MIT-licensed, allowing commercial use, modification, and distribution with minimal restrictions (retain license notice).

MIT is a permissive OSI license that explicitly permits commercial use and proprietary modification. However, verify that your use case complies with your organization's IP policy and dependency governance; no paid support or SLA is implied by the license.

DEV.co evaluation signals

Editorial assessment — not user reviews. Directional, with an explicit confidence level.

Signal	Assessment
Maintenance	Active
Documentation	Adequate
License clarity	Clear
Deployment complexity	Low
DEV.co fit	Good
Assessment confidence	High

Security considerations

Application Inspector is itself checked by CodeQL automated scanning. It performs local static analysis without network calls and does not send code to external services. As a pattern-matcher, it is not vulnerable to typical code-execution exploits in analyzed code. Review rule quality and false-negative rates in your threat model; detection accuracy is rule-dependent and may miss obfuscated or novel attack patterns.

Alternatives to consider

Semgrep

Open-source static analysis with broader vulnerability detection, language support, and a visual rule playground. Better for vulnerability-focused SAST; less focused on feature characterization.

SonarQube

Enterprise-grade platform with cloud/on-prem deployment, real-time dashboards, and deep code quality metrics. Requires separate installation and licensing; overkill for lightweight component vetting.

Snyk + Syft

SCA-focused with SBOM generation and supply chain risk. Complements Application Inspector for dependency auditing; not a replacement for feature-level source code analysis.

Software development agency

Build on ApplicationInspector with DEV.co software developers

Install Application Inspector via .NET CLI or download platform binaries to begin characterizing code dependencies and enforcing security policies.

Talk to DEV.co

Related open-source tools

Surfaced by semantic similarity across the DEV.co open-source index.

AttackSurfaceAnalyzer openappsec static-analysis

Related on DEV.co

Explore the category and the services that help you build with it.

Open-Source Security AI development DevOps Enterprise software Talk to DEV.co

ApplicationInspector FAQ

Can Application Inspector identify vulnerabilities like SQL injection or XSS?

No. It detects feature usage (e.g., presence of database APIs, cryptography) but does not perform semantic analysis to identify logic flaws or exploitable patterns. Use alongside SAST tools like Semgrep or SonarQube.

What languages are supported?

C, C++, C#, Java, JavaScript, HTML, Python, Objective-C, Go, Ruby, PowerShell, and more (see wiki for full list). Accuracy varies by language maturity; C# and Java are best-supported.

Can I customize or add new detection rules?

Yes. Rules are JSON-based and can be authored or modified. Use the verifyrules command to validate syntax. No visual IDE; editing and testing are manual. Community contributions are welcomed.

Does it require internet or send data to Microsoft?

No. Analysis is fully local and offline. Privacy is governed by Microsoft's standard privacy statement, but no telemetry or code transmission occurs during scanning.

Custom software development services

DEV.co is a software development agency delivering custom software development services to companies building on open source. Our software developers and web developers design, integrate, and ship production systems — spanning web development, APIs, AI, data, and cloud. If ApplicationInspector is part of your open-source security roadmap, our team can implement, customize, migrate, and maintain it.

Assess your codebase features in minutes.

Install Application Inspector via .NET CLI or download platform binaries to begin characterizing code dependencies and enforcing security policies.

Talk to DEV.co Schedule a Consultation