The Fuel indexer is a standalone service that can be used to index various components of the blockchain. These indexable components include blocks, transactions, receipts, and state within the Fuel network, allowing for high-performance read-only access to the blockchain for advanced dApp use-cases.

Want to get started right away? Check out our Quickstart!

For Users

Users of the Fuel indexer project include dApp developers looking to write flexible data-based backends for their dApp frontends, as well as index operators who are interested in managing one or many indexer projects for dApp developers.

Dependencies

`fuelup`

We use fuelup in order to get the binaries produced by services in the Fuel ecosystem. Fuelup will install binaries related to the Fuel node, the Fuel indexer, the Fuel orchestrator (forc), and other components.
fuelup can be downloaded here.

`WebAssembly`

Two additonal cargo components will be required to build your indexers: wasm-snip and the wasm32-unknown-unknown target.

To install wasm-snip:

cargo install wasm-snip

To install the wasm32-unknown-unknown target via rustup:

rustup target add wasm32-unknown-unknown

IMPORTANT: Users on Apple Silicon macOS systems may experience trouble when trying to build WASM modules due to its clang binary not supporting WASM targets. If encountered, you can install a binary with better support from Homebrew (brew install llvm) and instruct rustc to leverage it by setting the following environment variables:

AR=/opt/homebrew/opt/llvm/bin/llvm-ar

CC=/opt/homebrew/opt/llvm/bin/clang

`forc-index` Plugin

The primary way of developing Fuel indexers for end users is via the forc-index plugin. The forc-index plugin, is a CLI tool that is bundled with Fuel's primary CLI tooling interface, forc ("Fuel Orchestrator").

As mentioned in the dependencies section, the forc-index plugin is made available once you download fuelup.

If you've successfully gone through the Quickstart, you should already have forc-index installed and available in your PATH.

`forc index check`

Check to see which indexer components you have installed.

forc index check

`forc index new`

Create new indexer project at the provided path.

forc index new --namespace my_org_name

`forc index init`

Create a new indexer project at the provided path. If no path is provided the current working directory will be used.

forc index init --namespace my_org_name

`forc index build`

Build the indexer in the current directory.

forc index build

`forc index deploy`

Deploy a given indexer project to a particular endpoint

forc index deploy --url https://indexer.fuel.network

`forc index remove`

Kill a running indexer.

forc index remove --url https://indexer.fuel.network

`forc index auth`

Authenticate against an indexer service.

forc index auth --url https://indexer.fuel.network

`forc index start`

Start the indexer service.

forc index start

`forc index status`

Check the status of a registered indexer.

forc index status

Schema

The Fuel indexer uses data models derived from GraphQL schema types in order to persist data to a database backend.

type Account {
    id: ID!
    address: Address! @unique
}

GraphQL Functionality

While we do our best to maintain compliance with the GraphQL specification and parity with other implementations, there are a few things that are under development or will not be implemented. You can find more information in the GraphQL chapter of the book.

Modules

Within the context of the Fuel indexer, WebAssembly (WASM) modules are binaries that are compiled to a wasm32-unknown-unknown target, which can then be deployed to a running indexer service.

WebAssembly (WASM) modules

There are a few points that Fuel indexer users should know when using WASM:

WASM modules are only used if the execution mode specified in your manifest file is wasm.
Developers should be aware of what things may not work off-the-shelf in a module: file I/O, thread spawning, and anything that depends on system libraries. This is due to the technological limitations of WASM as a whole; more information can be found here.
As of this writing, there is a small bug in newly built Fuel indexer WASM modules that produces a WASM runtime error due to an errant upstream dependency. For now, a quick workaround requires the use of wasm-snip to remove the errant symbols from the WASM module. More info can be found in the related script here.

IMPORTANT: Users on Apple Silicon macOS systems may experience trouble when trying to build WASM modules due to its clang binary not supporting WASM targets. If encountered, you can install a binary with better support from Homebrew (brew install llvm) and instruct rustc to leverage it by setting the following environment variables:

export AR=/opt/homebrew/opt/llvm/bin/llvm-ar

export CC=/opt/homebrew/opt/llvm/bin/clang

For Contributors

Contributors of the Fuel indexer project are devs looking to help backends for their dApps.

Dev Dependencies

`docker`

IMPORTANT: Docker is not required to run the Fuel indexer.

We use Docker to produce reproducible environments for users that may be concerned with installing components with large sets of dependencies (e.g. PostgreSQL).
Docker can be downloaded here.

Database

At this time, the Fuel indexer requires the use of a database. We currently support a single database option: PostgreSQL. PostgreSQL is a database solution with a complex feature set and requires a database server.

PostgreSQL

Note: The following explanation is for demonstration purposes only. A production setup should use secure users, permissions, and passwords.

On macOS systems, you can install PostgreSQL through Homebrew. If it isn't present on your system, you can install it according to the instructions. Once installed, you can add PostgreSQL to your system by running brew install postgresql. You can then start the service through brew services start postgresql. You'll need to create a database for your indexed data, which you can do by running createdb [DATABASE_NAME]. You may also need to create the postgres role; you can do so by running createuser -s postgres.

For Linux-based systems, the installation process is similar. First, you should install PostgreSQL according to your distribution's instructions. Once installed, there should be a new postgres user account; you can switch to that account by running sudo -i -u postgres. After you have switched accounts, you may need to create a postgres database role by running createuser --interactive. You will be asked a few questions; the name of the role should be postgres and you should elect for the new role to be a superuser. Finally, you can create a database by running createdb [DATABASE_NAME].

In either case, your PostgreSQL database should now be accessible at postgres://postgres@localhost:5432/[DATABASE_NAME].

SQLx

After setting up your database, you should install sqlx-cli in order to run migrations for your indexer service.
You can do so by running cargo install sqlx-cli --features postgres.
Once installed, you can run the migrations by running the following command after changing DATABASE_URL to match your setup.

Building from Source

Clone repository

git clone git@github.com:FuelLabs/fuel-indexer.git && cd fuel-indexer/

Run migrations

PostgreSQL migrations

cd packages/fuel-indexer-database/postgres
DATABASE_URL=postgres://postgres@localhost sqlx migrate run

Start the service

cargo run --bin fuel-indexer

If no configuration file or other options are passed, the service will default to a postgres://postgres@localhost database connection.

Testing

Fuel indexer tests are currently broken out by a database feature flag. In order to run tests with a PostgreSQL backend, use --features postgres.

Further, the indexer uses end-to-end (E2E) tests. In order to trigger these end-to-end tests, you'll want to use the e2e features flag: --features e2e.

All end-to-end tests also require the use of a database feature. For example, to run the end-to-end tests with a Posgres backend, use --features e2e,postgres.

Default tests

cargo test --locked --workspace --all-targets

End-to-end tests

cargo test --locked --workspace --all-targets --features e2e,postgres

`trybuild` tests

For tests related to the meta-programming used in the Fuel indexer, we use trybuild.

RUSTFLAGS='-D warnings' cargo test -p fuel-indexer-macros --locked

Contributing

If you're interested in contributing PRs to make the Fuel indexer a better project, feel free to read our contributors document.

Read the book

Whether you're a user or a contributor, for more detailed info on how the Fuel indexer service works, make sure you read the book.

Platformtestnet2/fuel-indexer