RepoLantern
Menu
Start a guide

How RepoLantern turns a repository into a guide

A careful reading of the whole codebase, a cost you approve, and a guide checked against the code before you see it.

AELSHA™ RepoLantern is a free web app and command-line tool that turns any Git repository into a grounded documentation guide: architecture diagrams, citations to exact lines of code, and a check of every name it mentions against the code. You use your own AI model key.

How a guide is made: Read, Understand, Write, Check Four stages from left to right. 1 Read: fetches one commit, removes secrets, runs none of the code. Then you approve the cost. 2 Understand: summarises each file, then folders, then the whole system. 3 Write: writes each section for your audiences and draws real diagrams. 4 Check: looks up every name, links exact lines and scores the guide, so it is checked before you see it. Under Understand and Write: if a model limit is reached or you pause, finished work is kept, and the guide resumes on any model without redoing or billing it twice. You approve the cost Checked before you see it 1 Read Fetches one commit Removes secrets Runs none of the code 2 Understand Summarises each file, then folders, then the whole system 3 Write Writes each section for your audiences Draws real diagrams 4 Check Looks up every name Links exact lines Scores the guide Paused at a model limit, or by you? Finished work is kept. Resume on any model; nothing is redone or billed twice. How a guide is made: Read, Understand, Write, Check Four stages from top to bottom. 1 Read: fetches one commit, removes secrets, runs none of the code. Then you approve the cost. 2 Understand: summarises each file, then folders, then the whole system. 3 Write: writes each section for your audiences and draws real diagrams. 4 Check: looks up every name, links exact lines and scores the guide, so it is checked before you see it. If a model limit is reached or you pause, finished work is kept, and the guide resumes on any model without redoing or billing it twice. 1 Read Fetches one commit. Removes secrets. Runs none of the code. You approve the cost 2 Understand Summarises each file, then folders, then the whole system. 3 Write Writes each section for your audiences. Draws real diagrams. 4 Check Looks up every name. Links exact lines. Scores the guide. Checked before you see it Paused at a model limit, or by you? Finished work is kept. Resume on any model; nothing is redone or billed twice.

Open any stage for the details.

1. Read

Fetch the code at one commit, safely.

RepoLantern fetches the repository at one exact commit, without running any of its code. It lists every file, finds the languages, entry points, manifests and tests, and removes secrets such as keys and passwords before anything is sent to a model. Large repositories are split into parts that fit the model, and every file is summarised once and reused.

You approve the cost

Nothing is spent until you say yes.

Before any spend, you see how many files will be analysed, how long it will take, and the likely, low and high cost for your model, next to your limit. Nothing is spent until you approve.

2. Understand

From files to folders to the whole system.

File summaries are combined into folder and system views: the architecture, components and flows that every section shares.

3. Write

The guides you chose, from one analysis.

From that one analysis, RepoLantern writes the guides you chose: a beginner's guide, a senior engineer's guide and an architect's guide. Each has its own sections, such as a quick start, key concepts, architecture and data flow, module reference, setup and tests, and a glossary. Diagrams are drawn from the code's real imports.

4. Check

Checked against the code before you see it.

Every file path, function and class a guide mentions is looked up in the real code. A section with names that can't be found is rewritten once, and kept only if it improves. Anything still unverified is listed for you. Citations are resolved to exact lines and link to the analysed commit. How the checks work.

Pause and resume

Nothing finished is redone or billed twice.

Progress is saved step by step. If the server restarts, a model limit is reached or you pause, the job resumes where it stopped, on the same model or another one, without redoing or paying again for finished work. Limits and pauses.

Read, ask, export

Read the guide at three depths, ask questions beside it, and export it to Markdown, PDF, Word, PowerPoint, HTML or draw.io.

Engineered with AELSHA™ ASTRA

RepoLantern is built the way AELSHA™ builds agents for production: as a software system first, with every step observable, measured and gated. You can see this engineering in the app while a guide is made.

More on AELSHA™ ASTRA in RepoLantern · How RepoLantern observes itself

Light up your first codebase

Free to use. Bring your own model key; see the cost before anything is spent.

Start a guide