# Tannakian reconstruction

DevFeed: [Tannakian reconstruction](<https://devfeed.tech/articles/tannakian-reconstruction-28863.md>)

Original publisher: [Read original article](<https://bartoszmilewski.com/2026/07/14/tannakian-reconstruction/>)

Author: Bartosz Milewski

Published: 2026-07-14T10:51:53Z

Content type: tutorial

Language: en

Sources: [Bartosz Milewski's Programming Cafe](<https://devfeed.tech/sources/bartosz-milewski-s-programming-cafe.md>)

Topics: [structure](<https://devfeed.tech/topics/structure.md>)

Tags: [category-theory](<https://devfeed.tech/tags/category-theory.md>), [fiber-functor](<https://devfeed.tech/tags/fiber-functor.md>), [tannakian-reconstruction](<https://devfeed.tech/tags/tannakian-reconstruction.md>)

## AI overview

An explanatory article introduces Tannakian reconstruction through an analogy of superimposed photographs, then describes how functors, fiber functors, natural transformations, and ends can recover source-category morphisms.

## Source excerpt

Two friends, Alice and Bob, live in the same city, but on the opposite sides of a wide river. Every night, Bob looks at the lights on the other side and tries to guess, which one belongs to Alice. They come up with a clever arrangement: Alice will turn on her lights for 10 minutes [...]