diff --git a/HACKING.md b/HACKING.md
new file mode 100644
index 00000000..17e57fd3
--- /dev/null
+++ b/HACKING.md
@@ -0,0 +1,32 @@
+# Hacking arch3.js
+
+This document explains all you need to work on `arch3.js`, i.e. modify it. It is not intended for users of `arch3.js`.
+
+## Prerequisite
+
+- A UNIX-like development environment
+- Node.js 14+ and [yarn](https://yarnpkg.com/getting-started/install)
+
+## Installation
+
+1. Install dependencies: `yarn install`
+2. Install SDKs (to make IDE integration work): `yarn dlx @yarnpkg/sdks`
+
+## Running tests
+
+For unit tests that don't connect to any blockchain, just do:
+
+```sh
+yarn test
+```
+
+## Code Style
+
+After you modified a file, check if the linter is happy:
+
+```sh
+yarn lint
+
+# or if you want linting plus automatic fixing
+yarn lint:fix
+```
diff --git a/README.md b/README.md
index 8f88fe97..72e33791 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,7 @@
 # arch3.js
+
 The all-in-one library for your awesome Archway dApp
+
+## Development
+
+See [HACKING.md](./HACKING.md).