# Data Indexers

### The Graph

[The Graph](https://thegraph.com/) is the most popular blockchain indexing solution to simplify data delivery. The Graph indexes blockchain data based on subgraph descriptions and allows for effectively querying and filtering data with GraphQL.

[Official documentation](https://thegraph.com/docs/en/about/)

### Envio

[Envio](https://envio.dev/) is a self-hosted indexer for custom EVM chains. It is a simple tool to index data from your dApp and to use it to track stats or deliver data to the frontend.

[Official documentation](https://docs.envio.dev/docs/overview)

### Flair

[Flair](https://docs.flair.dev/) is a free indexing solution for maintaining an indexed database of filtered transactions for any EVM chain.

[Official documentation](https://docs.flair.dev/)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.lightlink.io/lightlink-protocol/tools-for-developers/data-indexers.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.