# @metamask/eth-json-rpc-middleware

> Ethereum-related json-rpc-engine middleware

Latest version **25.0.0** (published 2026-09-09) · ISC license · 0 weekly downloads

## Install

```sh
npm install @metamask/eth-json-rpc-middleware
pnpm add @metamask/eth-json-rpc-middleware
yarn add @metamask/eth-json-rpc-middleware
bun add @metamask/eth-json-rpc-middleware
```

## Health

**Score 65/100 (B)** — status: active.

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

Warnings: low downloads; no types.

## Facts

| | |
|---|---|
| Version | 25.0.0 |
| Published | 2026-09-09 |
| First published | 2023-02-02 |
| Weekly downloads | 0 |
| License | ISC |
| TypeScript types | none |
| Module format | ESM |
| Node | ^22.14.0 \|\| ^24 |
| Dependencies | 10 |
| Unpacked size | 259.4 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| Provenance | attested (GitHub Actions) |
| GitHub stars | 413 |
| Maintainers | frederikbolding, metamaskbot, gudahtt, mrten, mcmire, naugtur |
| Keywords | Ethereum, MetaMask |

## Links

- npm: https://www.npmjs.com/package/@metamask/eth-json-rpc-middleware
- Repository: https://github.com/MetaMask/core
- Homepage: https://github.com/MetaMask/core/tree/main/packages/eth-json-rpc-middleware#readme
- Issues: https://github.com/MetaMask/core/issues
- npm.io page: https://npm.io/package/@metamask/eth-json-rpc-middleware

## Dependencies (10)

- [klona](https://npm.io/package/klona.md) ^2.0.6
- [@metamask/utils](https://npm.io/package/@metamask/utils.md) ^11.12.0
- [@metamask/rpc-errors](https://npm.io/package/@metamask/rpc-errors.md) ^7.0.2
- [@metamask/superstruct](https://npm.io/package/@metamask/superstruct.md) ^3.4.1
- [safe-stable-stringify](https://npm.io/package/safe-stable-stringify.md) ^2.4.3
- [@metamask/eth-sig-util](https://npm.io/package/@metamask/eth-sig-util.md) ^9.0.0
- [@metamask/json-rpc-engine](https://npm.io/package/@metamask/json-rpc-engine.md) ^11.0.0
- [@metamask/message-manager](https://npm.io/package/@metamask/message-manager.md) ^15.0.0
- [@metamask/eth-block-tracker](https://npm.io/package/@metamask/eth-block-tracker.md) ^16.0.0
- [@metamask/eth-json-rpc-provider](https://npm.io/package/@metamask/eth-json-rpc-provider.md) ^7.0.0

## Recent versions

- 25.0.0 (latest) — 2026-09-09
- 24.0.2 — 2026-09-01
- 24.0.1 — 2026-08-26
- 24.0.0 — 2026-08-03
- 23.1.3 — 2026-04-28
- 23.1.2 — 2026-04-23
- 23.1.1 — 2026-03-26
- 23.1.0 — 2026-02-03
- 23.0.0 — 2026-01-15
- 22.0.1 — 2025-12-09
- 22.0.0 — 2025-11-20
- 21.0.0 — 2025-10-16
- 20.0.0 — 2025-10-15
- 19.0.1 — 2025-10-15
- 19.0.0 — 2025-10-09
- … 26 more at https://npm.io/package/@metamask/eth-json-rpc-middleware/versions

## README

# `@metamask/eth-json-rpc-middleware`

Ethereum-related middleware for [`json-rpc-engine`](https://github.com/MetaMask/json-rpc-engine).

See tests for usage details.

## Installation

`yarn add @metamask/eth-json-rpc-middleware`

or

`npm install @metamask/eth-json-rpc-middleware`

## See also

- [`@metamask/eth-json-rpc-filters`](https://github.com/MetaMask/eth-json-rpc-filters).
- [`@metamask/eth-json-rpc-infura`](https://github.com/MetaMask/eth-json-rpc-infura).
- [`@metamask/json-rpc-engine`](https://github.com/MetaMask/core/tree/main/packages/json-rpc-engine).

## Contributing

This package is part of a monorepo. Instructions for contributing can be found in the [monorepo README](https://github.com/MetaMask/core#readme).

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_Source: https://npm.io/package/@metamask/eth-json-rpc-middleware · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._