Sidekick is a dockerized backend you can run to perform blockchain reads/writes through simple HTTP endpoints while keeping private keys off the client. It integrates with Sequence services (Indexer, Transactions API, Node Gateway) and can hold keys locally or via KMS.

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What it’s for

  • Server-side write flows (e.g., mint ERC-1155/721, transfer, airdrops).
  • Secure key custody with local files, AWS KMS, or GCP KMS.
  • Simple HTTP endpoints so your app doesn’t need to embed signing logic.

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High-level setup

1

Run the container

Start Sidekick via Docker; configure environment variables for your access keys, networks, and key storage (local or KMS).
2

Get the smart account

Retrieve the Sidekick smart account address from the /sidekick/smart-account-address endpoint.
3

Grant permissions

Grant MINTER_ROLE (or transfer ownership) on your contracts to the Sidekick account, depending on your access control model.
4

Call endpoints

Use write endpoints (e.g., /write/erc1155/{chainId}/{contract address}/mint) and read endpoints as needed.

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Quickstart

There is a public docker image available on GitHub Container Registry. 
docker run -p 7500:7500 -e SEQUENCE_PROJECT_ACCESS_KEY=... ghcr.io/0xsequence/sidekick:latest
This will get you started with a local Sidekick backend running on port 7500 with the minimal features.
We recommend setting SEQUENCE_PROJECT_ACCESS_KEY as well but for testing purposes we provide a default one, you can get yours from Sequence Builder.
To do a full setup, you can follow the quickstart guide.

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Features and Use Cases

Effortless setup

Either use our public docker image or start it in dev mode with minimal configuration.

Flexible wallet options

Use a Sequence Smart Wallet with locally managed private keys or securely integrate AWS/GCP KMS for enhanced security.

Webhook management

Leverage our high-performance indexer to build and setup your own custom webhooks through the performant Sequence Indexer.

Tenderly integration

Leverage Tenderly to easily debug your transactions, you get a simulation URL for every transaction executed through Sidekick.

Automatic contract verification

Verifying contracts is cumbersome. Sidekick does it for you for every contract deployed.

Integrated with Sequence Builder

Already have a Sequence Builder project? Import all your contracts data into Sidekick with a single API call.

Built-in Bull MQ Dashboard

Create, monitor and manage your background jobs.

Swagger UI

Explore the API documentation and test the endpoints with the Swagger UI

Optimized transaction execution

Transactions are submitted at optimal gas prices, with automatic resubmission if not included in the mempool within three blocks.

Analytics and monitoring

Sidekick comes integrated with Grafana, Prometheus and Blackbox Exporter to monitor your backend health.

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Further Reading