safe-event-emitter(latest: 1.0.1) An `EventEmitter` that isolates the emitter from errors in handlers. If an error is thrown in a handler it is caught and re-thrown inside of a `setTimeout` so as to not interupt the emitter's code flow.
json-rpc-middleware-stream(latest: 2.1.1) A small toolset for streaming json rpc and matching requests and responses. Made to be used with `json-rpc-engine`.
eth-trezor-keyring(latest: 0.4.0) A MetaMask compatible keyring, for trezor hardware wallets
eth-method-registry(latest: 1.2.0) A module for getting method signature info from an ethereum method signature.
web3-sagas(latest: 0.3.1) Redux Sagas for Web3 and Truffle
obs-store(latest: 4.0.3) `ObservableStore` is a synchronous in-memory store for a single value, that you can subscribe to updates on.
eth-token-tracker(latest: 1.1.11) A module for tracking Ethereum token balances over block changes.
eth-block-tracker(latest: 4.4.3) A block tracker for the Ethereum blockchain. Keeps track of the latest block.
metamask-extension-provider(latest: 1.1.1) A module for allowing a WebExtension to access the web3 provider from an installed MetaMask instance.
json-rpc-capabilities-middleware(latest: 0.18.0) A module for managing basic [capability-based security](https://en.wikipedia.org/wiki/Capability-based_security) over a [JSON-RPC API](https://www.jsonrpc.org/) as a middleware function for [json-rpc-engine](https://www.npmjs.com/package/json-rpc-engine),
eth-json-rpc-filters(latest: 4.1.1) [json-rpc-engine](https://github.com/kumavis/json-rpc-engine) middleware implementing ethereum filter methods. Backed by an [eth-block-tracker](https://github.com/MetaMask/eth-block-tracker) and web3 provider interface (`web3.currentProvider`).
mm-plugin(latest: 0.3.13) MetaMask plugin development CLI.
snaps-cli(latest: 0.4.1) A CLI for developing MetaMask Snaps.