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

# Source documents

> Local copies of the official PDFs and what each document contributes to the transit documentation set.

## Primary PDFs

* [Transit specification PDF](/files/511/source/511-transit-spec.pdf)
* [Overview specification PDF](/files/511/source/511-overview-spec.pdf)
* [Data agreement PDF](/files/511/source/511-data-agreement.pdf)
* [Pathways coverage PDF](/files/511/source/511-pathways-stations.pdf)

## What each document is for

### Transit specification

The transit specification is the main technical source. It covers the transit endpoint families, request parameters, XML and JSON examples, SIRI message structures, GTFS+ files, historic feed notes, and shapes coverage.

### Overview specification

The overview specification defines the broader 511 data-exchange context: encoding, language, authentication, throttling, discovery, jurisdictions, and other shared protocol guidance.

### Data agreement

The data agreement defines the license, attribution expectations, branding limits, disclaimers, indemnification, and termination rules for anyone using 511-provided data.

### Pathways coverage

The pathways document is a coverage list. It identifies which stations and hubs are represented in pathways data.