stree is a CLI tool designed to visualize the directory tree structure of an S3 bucket. By inputting an S3 bucket/prefix and utilizing various flags to customize your request, you can obtain a colorized or non-colorized directory tree right in your terminal.

Uses machine learning to identify files in misconfigured buckets across a large number of providers, including AWS, Azure, Digital Ocean, GCP, and Alibaba. Requires an account to get results but the free tier is pretty useful in itself.

API documentation: https://openbuckets.io/api-docs

You have to have a Bounty Hunter subscription or higher to use it, though.

The last S3 security document that we’ll ever need, and how to use it.

Notea is a privacy-first, open-source note-taking application. It supports Markdown syntax, sharing, responsive and more. Notea is self-hosted, so your data is safe in your hands. In a few steps, it can be deployed to Vercel or Netlify, or even your own server via docker. Notea does not require a database. Notes are stored in AWS S3 bucket or compatible APIs. This means you can use MinIO (self-hosted), Aliyun OSS (like AWS S3) or NAS to store your data. You can publish your content to the web. With beautiful typography and new upcoming features, you can share your docs, wikis, blogs and newsletters with others using Notea.

Sits in front of S3 or Minio, lets you use it as a key/value datastore. Sort of like Redis, but with HTTP.

A search engine for open and unsecured Amazon S3 buckets.

Has a REST API. Have a key.

Minio is an opensource object storage system that is functionally compatible with Amazon's S3 service. It's written in go and aims for minimalism, scalability, and reliability with automatic erasure coding and checksums of data. If you can throw it in an S3 bucket, you can throw it in a Minio bucket. Objects top out at 5TB in size. The executable itself tops out at 22 MB in size. Even has an online webapp that lets you browse buckets and their contents.