> For the complete documentation index, see [llms.txt](https://docs.herodotus.dev/herodotus-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.herodotus.dev/herodotus-docs/developers/data-structure-indexer-api.md).

# Data Structure Indexer API

The Data Structure Proofs API is a read-only API designed to help developers work with off-chain data structures used by Herodotus. Even though these data structures are kept off-chain, they have their roots committed on-chain. 

{% hint style="danger" %}
Most developers are unlikely to directly interact with this API, as its usage happens behind the scenes when interacting with the Storage Proof API.
{% endhint %}

Developers can query the Data Structure Indexer to retrieve:

* [Herodotus block hash accumulators](/herodotus-docs/protocol-design/historical-block-hash-accumulator.md)
* Individual block data within these accumulators
* Verifiable binary search path [linking a timestamp to a specific block numbers](/herodotus-docs/protocol-design/timestamp-to-block-number-mapper.md)
* List of timestamp remappers that Herodotus manages and indexes
* The peaks of a specific accumulator MMR
* MMR inclusion proofs for specific blocks

## Interactive Documentation

<https://rs-indexer.api.herodotus.cloud/swagger/>

<https://rs-indexer.api.herodotus.cloud/rapidoc/>

<https://rs-indexer.api.herodotus.cloud/redoc/>