AWS Threat Composer

Overview

AWS Threat Composer is a threat-modeling project for identifying security issues and developing ways to address them. Its structured threat grammar offers adaptive suggestions for composing threat statements. Models can include architecture and data-flow diagrams, tracked assumptions, links between threats and mitigations, and an insights dashboard with quality metrics and improvement suggestions. Users can manage multiple models and export them as JSON, Markdown, DOCX, or PDF. The web application stores data in the browser, supports import and export, and is available as a hosted demo or as a static site deployed in an AWS account. The VS Code extension in AWS Toolkit edits .tc.json files, works offline, and stores data locally. A browser extension displays threat model files on GitHub, GitLab, Bitbucket, and Amazon CodeCatalyst; it is read-only and requires internet access for web-hosted files. The AI-assisted CLI and MCP server can analyze source code to create starter models, but the tools are experimental. They use AWS Bedrock, and inference costs apply.

Who it is for

It suits people modeling system threats who want diagrams, linked mitigations, and portable model files. The VS Code integration also supports keeping models alongside code in version control.

Compared on threat modeling software

Free plan

Yesawslabs.github.io

Risk prioritization

Yesawslabs.github.io

Collaborative review

Yesawslabs.github.io

Templates and frameworks

Yesawslabs.github.io

Deployment

bothawslabs.github.io

Facts

Purpose

Threat Composer helps users identify security issues and develop strategies to address them through iterative threat modeling.github.com · 2 Oct 2026

Threat writing

It uses structured threat grammar with adaptive suggestions to help compose threat statements.github.com · 2 Oct 2026

Modeling features

It supports architecture and data flow diagrams, assumptions tracking, threat and mitigation links, and an insights dashboard.github.com · 2 Oct 2026

Exports

Threat models can be exported in JSON, Markdown, DOCX, and PDF formats.github.com · 2 Oct 2026

Web app storage

The web application uses browser-based storage and supports import and export.github.com · 2 Oct 2026

Self-hosting

The web application can be deployed to an AWS account with customization.github.com · 2 Oct 2026

AI tools

The AI-assisted CLI and MCP server analyze source code to generate starter threat models; the AI tools are marked experimental.github.com · 2 Oct 2026

AI cost

The project page says AWS Bedrock inference costs apply to the AI-powered CLI and MCP server.github.com · 2 Oct 2026

VS Code

The VS Code extension is included in AWS Toolkit and edits .tc.json files; its documentation says it works offline and stores data in local files.github.com · 2 Oct 2026

Browser extension integrations

The browser extension supports GitHub, GitLab, Bitbucket, and Amazon CodeCatalyst, including configurable URL patterns for self-hosted instances.github.com · 2 Oct 2026

Browser extension limits

The browser extension is read-only, requires internet access to load web files, and its documentation says Chrome Web Store and Firefox Add-ons publication is not yet available.github.com · 2 Oct 2026

Browser extension privacy

Its documentation says it does not collect or transmit data, uses no analytics or tracking, and makes no external API calls.github.com · 2 Oct 2026

Audience and workflow

The project is designed for people threat modeling systems, and its VS Code integration supports keeping threat models alongside code in version control.github.com · 2 Oct 2026

Support

The project directs users to GitHub Issues and GitHub Discussions for bug reports, feature requests, and questions.github.com · 2 Oct 2026

Threat statements

It uses structured threat grammar with adaptive suggestions to help users compose threat statements.github.com · 3 Oct 2026

Diagrams and insights

Features include architecture and data flow diagrams, plus an insights dashboard with quality metrics and improvement suggestions.github.com · 3 Oct 2026

Model management

Users can track assumptions, link them to threats and mitigations, manage multiple models, and export models as JSON, Markdown, DOCX, or PDF.github.com · 3 Oct 2026

Web app

The web application is available as a hosted demo or as a static website users can self-host in their AWS account; it supports browser-based storage and import/export.github.com · 3 Oct 2026

AI usage costs

The AI CLI and MCP server use AWS Bedrock, and Bedrock inference costs apply.github.com · 3 Oct 2026

Browser integrations

The browser extension supports viewing threat model files on GitHub, GitLab, Bitbucket, and Amazon CodeCatalyst; its documentation says Chrome Web Store and Firefox Add-ons publication is not yet available.github.com · 3 Oct 2026

Browser extension limitation

The browser extension provides read-only viewing, requires internet access to load web-hosted files, and may take time to load large models.github.com · 3 Oct 2026

Support and security reports

The project directs users to GitHub Issues and Discussions for feedback and support, and asks that security vulnerabilities be reported through AWS's Vulnerability Disclosure Program or [email protected].github.com · 3 Oct 2026

Where it ranks on Specifiction

• Best Threat Modeling Software in 2026#4 of 22

Sources

• github.com/awslabs/threat-composer· checked 2 Oct 2026
• github.com/awslabs/threat-composer/blob/main/docs/· checked 2 Oct 2026
• github.com/awslabs/threat-composer/blob/main/docs/· checked 2 Oct 2026