LLMSchema

LLMSchema is a self-hosted developer tool that turns relational database structures into Markdown for coding agents and documentation workflows. It suits teams working with PostgreSQL, MySQL, or SQLite who want schema context in source control without paying for a hosted service. Its development-only positioning makes it best treated as an aid for AI-assisted coding, not as an authoritative production record.

Overview

LLMSchema generates documentation from PostgreSQL, MySQL, and SQLite databases. The output covers tables, columns, data types, indexes, constraints, and relationships, giving an AI coding assistant a compact view of how an application’s relational data fits together. Because the result is Markdown, it can sit beside code and be read by both developers and language models.

The project is MIT licensed and free to use. It runs locally or on infrastructure you control, avoiding a hosted documentation subscription. The trade-off is that you own installation, execution, and whatever process keeps generated files current. The project explicitly targets development databases and should not be relied on for production-critical documentation.

Key features

Markdown schema output

LLMSchema can write one portable Markdown document or an overview accompanied by a separate Markdown file for every table. A single file is convenient for straightforward agent instructions; split files are more practical when a repository is large or when prompts should point an agent to narrower table-level context.

Selective documentation

Include and exclude filters let you limit generated content to chosen tables. That keeps prompts and checked-in documentation focused, and helps teams avoid exposing irrelevant development tables to an agent.

Automation and interfaces

The command-line tool can be added to a Makefile or migration script so documentation is regenerated as schemas change. The same project is available as a Go library, which gives Go-based tooling a programmatic integration path rather than requiring shell orchestration. The README also recommends telling an agent where the files live through AGENTS.md, CLAUDE.md, or an equivalent instruction file.

Coverage is intentionally centered on core relational schema objects. Views and materialized views, PostgreSQL triggers and functions, and table and column comments are identified as areas for exploration, so workflows that depend on those objects should expect an incomplete picture.

Pricing

Free (MIT-licensed software) — 0.00 USD

This is the only plan: free CLI and Go library access for PostgreSQL, MySQL, and SQLite. There is no paid tier, renewal, seat charge, quota, or trial period. That makes LLMSchema a sensible choice for individual developers and teams that can run tooling in their own environments. You give up the convenience of a commercial support package and broader documentation coverage, so organizations needing production-grade governance should look elsewhere.

Platforms

LLMSchema supports Linux, macOS, Windows, and self-hosted deployment. Go installation instructions and a quick-install script are provided for macOS and Linux; Windows users can use the command-line and library on that platform but should expect to manage installation themselves. Self-hosting suits repositories with strict control over database access and generated files.

Who it's for

Choose LLMSchema if you are a developer or small team using a supported relational database and want deterministic Markdown context for AI-assisted coding. It is particularly suitable when schema files belong in version control and a Makefile or migration process can regenerate them.

It is a poor fit when documentation must describe production-only objects, serve as a formal data dictionary, or be maintained by nontechnical users through a hosted interface. The project’s stated development-database boundary is important for any operational or compliance workflow.

Pros and cons

Pros

• Free and MIT licensed: there is no subscription or seat cost, and the code can be self-hosted.
• Useful relational coverage: tables, columns, types, indexes, constraints, and relationships provide the essentials for coding assistance.
• Flexible Markdown layouts: one file or one file per table supports both simple and large repositories.
• Automation-friendly: Makefile and migration-script integration can keep checked-in docs aligned with development changes.
• CLI and Go library: teams can use a command or embed generation in Go tooling.

Cons

• Not for production-critical records: the project itself limits its reliability claim to development databases.
• Object coverage has gaps: views, materialized views, PostgreSQL triggers and functions, and comments are not established parts of the documented scope.
• Self-managed operation: installation and update automation remain the user’s responsibility.
• Relational-only focus: teams using nonrelational systems need another tool.

Alternatives

Browse Database Documentation Tools for a wider category comparison.

MySQL is the stronger choice when you need a full database platform with a freemium model, a trial, and replication, high-availability components, and connectors beyond schema-to-Markdown generation.

Pick DBDock for an open-source MIT-licensed CLI with self-hosting and broader API, web, and desktop platform coverage.

dbdocs fits teams wanting a hosted documentation service, public sharing, password protection, and a paid single-user tier with annual billing options.

Choose dbForge Studio for PostgreSQL when PostgreSQL work benefits from an Express edition with code completion, formatting, query history, visual editing, and data transfer tools.

DbSchema is better for visual schema design and synchronization, with Pro and Architect upgrades beyond its community offering.

DBX is another free, open-source documentation tool with self-hosted, web, and desktop availability.

Taavik suits users who need a hosted database workspace with members, saved queries, schedules, history, and query-run limits on its free tier.

tbls is a straightforward alternative if you prefer an MIT-licensed, single-binary CLI for database documentation.

Verdict

LLMSchema is a strong pick for developers who want free, self-hosted Markdown schema context for AI coding workflows across PostgreSQL, MySQL, or SQLite. Its filtering, automation hooks, and CLI/Go interfaces make it practical to keep development documentation near the code. Look elsewhere if you need production assurance, richer database-object coverage, visual design, or a managed documentation experience.