# @onflow/fcl-core

> Core JavaScript/TypeScript library providing shared functionality for Flow blockchain interactions.

Latest version **1.30.3** (published 2026-06-23) · Apache-2.0 license · 0 weekly downloads

## Install

```sh
npm install @onflow/fcl-core
pnpm add @onflow/fcl-core
yarn add @onflow/fcl-core
bun add @onflow/fcl-core
```

## Health

**Score 75/100 (B)** — status: active.

Positive: has types; esm support; no vulnerabilities; has provenance; recently updated; high maintenance score; high quality score.

Warnings: low downloads.

## Facts

| | |
|---|---|
| Version | 1.30.3 |
| Published | 2026-06-23 |
| First published | 2023-12-04 |
| Weekly downloads | 0 |
| License | Apache-2.0 |
| TypeScript types | bundled |
| Module format | ESM + CommonJS |
| Dependencies | 18 |
| Unpacked size | 1.7 MB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| Provenance | attested (GitHub Actions) |
| GitHub stars | 333 |
| Author | Flow Foundation |
| Maintainers | han210, dapperj, dapper_labs, jeffreydoyle, harry.eth, chasefleming, gregorggg, turbolent_ff, jribbink, kan-flow-foundation, michael_flow, lmcmze |

## Links

- npm: https://www.npmjs.com/package/@onflow/fcl-core
- Repository: https://github.com/onflow/fcl-js
- Homepage: https://flow.com
- Issues: https://github.com/onflow/fcl-js/issues
- npm.io page: https://npm.io/package/@onflow/fcl-core

## Dependencies (18)

- [uuid](https://npm.io/package/uuid.md) ^11.1.0
- [@onflow/rlp](https://npm.io/package/@onflow/rlp.md) 1.2.4
- [@onflow/sdk](https://npm.io/package/@onflow/sdk.md) 1.13.7
- [cross-fetch](https://npm.io/package/cross-fetch.md) ^4.0.0
- [@onflow/types](https://npm.io/package/@onflow/types.md) 1.5.0
- [@babel/runtime](https://npm.io/package/@babel/runtime.md) ^7.25.7
- [@onflow/config](https://npm.io/package/@onflow/config.md) 1.11.1
- [@onflow/util-uid](https://npm.io/package/@onflow/util-uid.md) 1.2.4
- [abort-controller](https://npm.io/package/abort-controller.md) ^3.0.0
- [@onflow/util-actor](https://npm.io/package/@onflow/util-actor.md) 1.3.5
- [@onflow/interaction](https://npm.io/package/@onflow/interaction.md) 0.0.11
- [@onflow/util-logger](https://npm.io/package/@onflow/util-logger.md) 1.3.4
- [@onflow/util-semver](https://npm.io/package/@onflow/util-semver.md) 1.0.4
- [@onflow/util-address](https://npm.io/package/@onflow/util-address.md) 1.2.4
- [@onflow/util-template](https://npm.io/package/@onflow/util-template.md) 1.2.4
- [@onflow/transport-http](https://npm.io/package/@onflow/transport-http.md) 1.15.6
- [@onflow/util-invariant](https://npm.io/package/@onflow/util-invariant.md) 1.2.5
- [@improbable-eng/grpc-web](https://npm.io/package/@improbable-eng/grpc-web.md) ^0.15.0

## Recent versions

- 1.30.3 (latest) — 2026-06-23
- 1.21.0-alpha.2 (alpha) — 2025-07-24
- 1.17.0-kit.0 (kit) — 2025-04-23
- 1.17.0-cross-vm.2 (cross-vm) — 2025-04-08
- 1.12.0-deeplink.0 (deeplink) — 2024-10-11
- 1.30.2 — 2026-03-25
- 1.30.1 — 2025-12-12
- 1.30.0 — 2025-12-12
- 1.29.0 — 2025-12-12
- 1.23.1 — 2025-12-10
- 1.23.0 — 2025-12-09
- 1.22.3 — 2025-11-28
- 1.22.2 — 2025-11-17
- 1.22.1 — 2025-11-06
- 1.22.0 — 2025-10-21
- … 56 more at https://npm.io/package/@onflow/fcl-core/versions

## README

# FCL: Flow Client Library
### Making secure web applications powered by the Flow Blockchain

Flow Client Library (FCL) enables applications to easily integrate with all FCL-compatible wallets and
other services (e.g. (Coming Soon) profiles, private information, notifications). This offers developers a strong
foundation to compose their apps with existing building blocks. It’s currently supported for browser
applications, and will be extended to other platforms.

With FCL, you can:

- Integrate all compatible wallets without any custom code or code injection
- Authenticate users
- Query the Flow Blockchain
- Send transactions (e.g. initializing resources, sending assets, purchasing, etc.)
- Sign transactions through wallet integration avoiding key management

With FCL, you will eventually be able to:

- Personally sign data via FCL Compatible Wallets
- Request Additional User info like Emails

## Status

- **Last Updated:** Mar 2nd 2021
- **Stable:** Yes
- **Risk of Breaking Change:** Low

The things that exists probably won't be changing much externally, we will be adding new functionality in the near future.

## Install

```bash
npm install --save @onflow/fcl
```

## Getting Started

For a detailed guide explaining how to use `@onflow/fcl` to interact with Flow please see the [Flow App Quick Start](https://developers.flow.com/tutorials/flow-app-quickstart)

Having trouble with something? Reach out to us on [Discord](https://discord.gg/k6cZ7QC), we are more than happy to help.

---
_Source: https://npm.io/package/@onflow/fcl-core · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._