> ## Documentation Index
> Fetch the complete documentation index at: https://docs.snakream.tonbo.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Streams

> Understand Snakream's core append-only stream primitive and its lifecycle.

A stream is an append-only byte sequence. Once data is written, it cannot be modified or reordered. Only new data can be appended to the end.

Every stream has a URL (e.g. `/ds/myapp/user-42`) and goes through a simple lifecycle:

* **Open**: accepts appends. This is the default state on creation.
* **Closed**: permanently sealed. Readers see an EOF signal; further appends are rejected. Useful for marking a completed session or a finalized document.
* **Deleted**: removed entirely.

Closing is explicit (`Stream-Closed: true` header on a POST) and irreversible.