diff --git a/.github/workflows/ci-common.yml b/.github/workflows/ci-common.yml
new file mode 100644
index 0000000..b1f2adc
--- /dev/null
+++ b/.github/workflows/ci-common.yml
@@ -0,0 +1,66 @@
+name: CI checks for common workspace
+
+on:
+  pull_request:
+    branches: ['main']
+    paths: ['common/**/*', '!**/*.{txt,md}']
+  push:
+    branches: ['main']
+    paths: ['common/**/*', '!**/*.{txt,md}']
+
+defaults:
+  run:
+    working-directory: 'common'
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          cache: 'yarn'
+      - name: Install yarn
+        run: npm install -g yarn
+      - name: Install dependencies
+        run: yarn
+      - name: Run tests
+        run: yarn test
+  eslint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          cache: 'yarn'
+      - name: Install yarn
+        run: npm install -g yarn
+      - name: Install dependencies
+        run: yarn
+      - name: Run ESLint
+        run: yarn eslint .
+  prettier:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          cache: 'yarn'
+      - name: Install yarn
+        run: npm install -g yarn
+      - name: Install dependencies
+        run: yarn
+      - name: Run Prettier
+        run: yarn prettier . --check --ignore-unknown
+  typecheck:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          cache: 'yarn'
+      - name: Install yarn
+        run: npm install -g yarn
+      - name: Install dependencies
+        run: yarn
+      - name: Run tsc to check types
+        run: yarn tsc --noEmit --strict
diff --git a/common/eslint.config.mjs b/common/eslint.config.mjs
new file mode 100644
index 0000000..0c9cd26
--- /dev/null
+++ b/common/eslint.config.mjs
@@ -0,0 +1,17 @@
+import globals from 'globals'
+import pluginJs from '@eslint/js'
+import tseslint from 'typescript-eslint'
+
+/** @type {import('eslint').Linter.Config[]} */
+export default [
+  { files: ['**/*.{js,mjs,cjs,ts}'] },
+  { languageOptions: { globals: { ...globals.browser, ...globals.node } } },
+  pluginJs.configs.recommended,
+  ...tseslint.configs.recommended,
+  {
+    rules: {
+      '@typescript-eslint/no-explicit-any': 'off', // disable this particular rule for now, since the `any` annotations are very tricky to get rid of
+      '@typescript-eslint/no-unused-expressions': 'off', // turn this off too for now, otherwise ESLint says "Cannot read properties of undefined"
+    },
+  },
+]
diff --git a/common/jest.config.js b/common/jest.config.js
index 22b1bda..8f9b097 100644
--- a/common/jest.config.js
+++ b/common/jest.config.js
@@ -1,11 +1,11 @@
 /** @type {import('ts-jest').JestConfigWithTsJest} */
-const { pathsToModuleNameMapper } = require('ts-jest')
-const { compilerOptions } = require('./tsconfig')
+import { pathsToModuleNameMapper } from 'ts-jest'
+import tsconfig from './tsconfig.js'
 
-module.exports = {
+export default {
   preset: 'ts-jest',
   testEnvironment: 'node',
-  moduleNameMapper: pathsToModuleNameMapper(compilerOptions.paths, {
+  moduleNameMapper: pathsToModuleNameMapper(tsconfig.compilerOptions.paths, {
     prefix: '<rootDir>/',
   }),
   testMatch: ['**/*.test.ts'],
diff --git a/common/package.json b/common/package.json
index b17f1df..490402c 100644
--- a/common/package.json
+++ b/common/package.json
@@ -1,5 +1,6 @@
 {
   "name": "common",
+  "type": "module",
   "version": "1.0.0",
   "private": true,
   "scripts": {
@@ -25,11 +26,15 @@
     "zod": "3.21.4"
   },
   "devDependencies": {
+    "@eslint/js": "9.32.0",
     "@types/jest": "29.2.4",
     "@types/lodash": "4.14.178",
     "@types/string-similarity": "4.0.0",
+    "eslint": "9.32.0",
+    "globals": "16.3.0",
     "jest": "29.3.1",
     "supabase": "2.15.8",
-    "ts-jest": "29.0.3"
+    "ts-jest": "29.0.3",
+    "typescript-eslint": "8.39.0"
   }
 }
diff --git a/common/src/api/schema.ts b/common/src/api/schema.ts
index d0374b0..01a6dcd 100644
--- a/common/src/api/schema.ts
+++ b/common/src/api/schema.ts
@@ -36,9 +36,9 @@ type APIGenericSchema = {
   cache?: string
 }
 
-let _apiTypeCheck: { [x: string]: APIGenericSchema }
+type apiTypeCheck = { [x: string]: APIGenericSchema }
 
-export const API = (_apiTypeCheck = {
+export const API: apiTypeCheck = {
   health: {
     method: 'GET',
     authed: false,
@@ -476,7 +476,7 @@ export const API = (_apiTypeCheck = {
       radius: z.number().min(1).max(500),
     }),
   },
-} as const)
+} as const
 
 export type APIPath = keyof typeof API
 export type APISchema<N extends APIPath> = (typeof API)[N]
diff --git a/common/src/api/websocket-client.ts b/common/src/api/websocket-client.ts
index 74ee83e..ae30565 100644
--- a/common/src/api/websocket-client.ts
+++ b/common/src/api/websocket-client.ts
@@ -86,7 +86,7 @@ export class APIRealtimeClient {
       // to connect, so we need to turn on our reconnect in that case
       this.waitAndReconnect()
     }
-    this.ws.onopen = (_ev) => {
+    this.ws.onopen = () => {
       if (VERBOSE_LOGGING) {
         console.info('API websocket opened.')
       }
diff --git a/common/src/api/zod-types.ts b/common/src/api/zod-types.ts
index c3cab69..853266c 100644
--- a/common/src/api/zod-types.ts
+++ b/common/src/api/zod-types.ts
@@ -8,7 +8,6 @@ export const arraybeSchema = z
   .or(z.string())
   .transform(arrify)
 
-// @ts-ignore
 export const contentSchema: z.ZodType<JSONContent> = z.lazy(() =>
   z.intersection(
     z.record(z.any()),
diff --git a/common/src/envs/is-prod.ts b/common/src/envs/is-prod.ts
index 76d98ff..251d620 100644
--- a/common/src/envs/is-prod.ts
+++ b/common/src/envs/is-prod.ts
@@ -1,3 +1,5 @@
+import admin from 'firebase-admin'
+
 export const isProd = () => {
   // For cloud run API service
   if (process.env.ENVIRONMENT) {
@@ -7,8 +9,6 @@ export const isProd = () => {
     return process.env.NEXT_PUBLIC_FIREBASE_ENV == 'PROD'
   } else {
     // For local scripts and cloud functions
-    // eslint-disable-next-line @typescript-eslint/no-var-requires
-    const admin = require('firebase-admin')
     return admin.app().options.projectId === 'polylove'
   }
 }
diff --git a/common/src/love/lover.ts b/common/src/love/lover.ts
index f334178..cf2da97 100644
--- a/common/src/love/lover.ts
+++ b/common/src/love/lover.ts
@@ -1,6 +1,6 @@
 import { Row, run, SupabaseClient } from 'common/supabase/utils'
 import { User } from 'common/user'
-import { Database } from 'common/supabase/schema'
+//import { Database } from 'common/supabase/schema'
 
 export type LoverRow = Row<'lovers'>
 export type Lover = LoverRow & { user: User }
diff --git a/common/src/secrets.ts b/common/src/secrets.ts
index fe85a2d..c6dc647 100644
--- a/common/src/secrets.ts
+++ b/common/src/secrets.ts
@@ -91,7 +91,7 @@ export const getServiceAccountCredentials = (env: 'PROD' | 'DEV') => {
 
   try {
     return JSON.parse(readFileSync(keyPath, { encoding: 'utf8' }))
-  } catch (e) {
+  } catch {
     throw new Error(`Failed to load service account key from ${keyPath}.`)
   }
 }
diff --git a/common/src/socials.test.ts b/common/src/socials.test.ts
index e1bfbb2..ce84c8e 100644
--- a/common/src/socials.test.ts
+++ b/common/src/socials.test.ts
@@ -23,7 +23,9 @@ describe('strip', () => {
 
   describe('instagram', () => {
     it('should strip instagram URLs', () => {
-      expect(strip('instagram', 'https://instagram.com/username')).toBe('username')
+      expect(strip('instagram', 'https://instagram.com/username')).toBe(
+        'username'
+      )
       expect(strip('instagram', 'instagram.com/username')).toBe('username')
       expect(strip('instagram', '@username')).toBe('username')
       expect(strip('instagram', 'username')).toBe('username')
@@ -32,7 +34,9 @@ describe('strip', () => {
 
   describe('bluesky', () => {
     it('should strip bluesky URLs', () => {
-      expect(strip('bluesky', 'https://bsky.app/profile/username')).toBe('username')
+      expect(strip('bluesky', 'https://bsky.app/profile/username')).toBe(
+        'username'
+      )
       expect(strip('bluesky', 'bsky.app/profile/username')).toBe('username')
       expect(strip('bluesky', '@username')).toBe('username')
       expect(strip('bluesky', 'username')).toBe('username')
@@ -41,16 +45,24 @@ describe('strip', () => {
 
   describe('mastodon', () => {
     it('should handle mastodon handles', () => {
-      expect(strip('mastodon', '@user@instance.social')).toBe('user@instance.social')
-      expect(strip('mastodon', 'user@instance.social')).toBe('user@instance.social')
+      expect(strip('mastodon', '@user@instance.social')).toBe(
+        'user@instance.social'
+      )
+      expect(strip('mastodon', 'user@instance.social')).toBe(
+        'user@instance.social'
+      )
     })
   })
 
   describe('linkedin', () => {
     it('should strip linkedin URLs', () => {
-      expect(strip('linkedin', 'https://linkedin.com/in/username')).toBe('username')
+      expect(strip('linkedin', 'https://linkedin.com/in/username')).toBe(
+        'username'
+      )
       expect(strip('linkedin', 'linkedin.com/in/username')).toBe('username')
-      expect(strip('linkedin', 'https://linkedin.com/company/companyname')).toBe('companyname')
+      expect(
+        strip('linkedin', 'https://linkedin.com/company/companyname')
+      ).toBe('companyname')
       expect(strip('linkedin', 'username')).toBe('username')
     })
   })
@@ -59,22 +71,42 @@ describe('strip', () => {
 describe('getSocialUrl', () => {
   it('should generate correct URLs for each platform', () => {
     expect(getSocialUrl('x', 'username')).toBe('https://x.com/username')
-    expect(getSocialUrl('github', 'username')).toBe('https://github.com/username')
-    expect(getSocialUrl('instagram', 'username')).toBe('https://instagram.com/username')
-    expect(getSocialUrl('bluesky', 'username')).toBe('https://bsky.app/profile/username')
-    expect(getSocialUrl('mastodon', 'user@instance.social')).toBe('https://instance.social/@user')
-    expect(getSocialUrl('linkedin', 'username')).toBe('https://linkedin.com/in/username')
-    expect(getSocialUrl('facebook', 'username')).toBe('https://facebook.com/username')
-    expect(getSocialUrl('spotify', 'username')).toBe('https://open.spotify.com/user/username')
+    expect(getSocialUrl('github', 'username')).toBe(
+      'https://github.com/username'
+    )
+    expect(getSocialUrl('instagram', 'username')).toBe(
+      'https://instagram.com/username'
+    )
+    expect(getSocialUrl('bluesky', 'username')).toBe(
+      'https://bsky.app/profile/username'
+    )
+    expect(getSocialUrl('mastodon', 'user@instance.social')).toBe(
+      'https://instance.social/@user'
+    )
+    expect(getSocialUrl('linkedin', 'username')).toBe(
+      'https://linkedin.com/in/username'
+    )
+    expect(getSocialUrl('facebook', 'username')).toBe(
+      'https://facebook.com/username'
+    )
+    expect(getSocialUrl('spotify', 'username')).toBe(
+      'https://open.spotify.com/user/username'
+    )
   })
 
   it('should handle custom website URLs', () => {
     expect(getSocialUrl('site', 'example.com')).toBe('https://example.com')
-    expect(getSocialUrl('site', 'https://example.com')).toBe('https://example.com')
+    expect(getSocialUrl('site', 'https://example.com')).toBe(
+      'https://example.com'
+    )
   })
 
   it('should handle discord user IDs and default invite', () => {
-    expect(getSocialUrl('discord', '123456789012345678')).toBe('https://discord.com/users/123456789012345678')
-    expect(getSocialUrl('discord', 'not-an-id')).toBe('https://discord.com/invite/AYDw8dbrGS')
+    expect(getSocialUrl('discord', '123456789012345678')).toBe(
+      'https://discord.com/users/123456789012345678'
+    )
+    expect(getSocialUrl('discord', 'not-an-id')).toBe(
+      'https://discord.com/invite/AYDw8dbrGS'
+    )
   })
-})
\ No newline at end of file
+})
diff --git a/common/src/util/algos.ts b/common/src/util/algos.ts
index 7fe2118..95b7a98 100644
--- a/common/src/util/algos.ts
+++ b/common/src/util/algos.ts
@@ -5,7 +5,7 @@ export function binarySearch(
 ) {
   let mid = 0
   let i = 0
-  while (true) {
+  while (i <= 100000) {
     mid = min + (max - min) / 2
 
     // Break once we've reached max precision.
diff --git a/common/src/util/api.ts b/common/src/util/api.ts
index 9005cd3..4849f6c 100644
--- a/common/src/util/api.ts
+++ b/common/src/util/api.ts
@@ -15,7 +15,7 @@ export const typedAPICall = <P extends APIPath>(
 ) => {
   // parse any params that should part of the path (like market/:id)
   const newParams: any = {}
-  let url = getApiUrl(path)
+  let url: string = getApiUrl(String(path)) // `path` could be a string or number, we don't know
   forEach(params, (v, k) => {
     if (url.includes(`:${k}`)) {
       url = url.replace(`:${k}`, v + '')
diff --git a/common/src/util/json.ts b/common/src/util/json.ts
index bbdf56e..e772069 100644
--- a/common/src/util/json.ts
+++ b/common/src/util/json.ts
@@ -1,7 +1,7 @@
 export const safeJsonParse = (json: string | undefined | null) => {
   try {
-    return JSON.parse(json ?? '') 
-  } catch (e) {
+    return JSON.parse(json ?? '')
+  } catch {
     return null
   }
 }
diff --git a/common/src/util/parse.ts b/common/src/util/parse.ts
index 74713b1..11a7922 100644
--- a/common/src/util/parse.ts
+++ b/common/src/util/parse.ts
@@ -2,7 +2,7 @@ import {
   getText,
   getSchema,
   getTextSerializersFromSchema,
-  Node,
+  //Node,
   JSONContent,
 } from '@tiptap/core'
 import { Node as ProseMirrorNode } from '@tiptap/pm/model'
diff --git a/common/src/util/random.ts b/common/src/util/random.ts
index b9c34cc..6162281 100644
--- a/common/src/util/random.ts
+++ b/common/src/util/random.ts
@@ -51,4 +51,4 @@ export const shuffle = (array: unknown[], rand: () => number) => {
     const swapIndex = i + Math.floor(rand() * (array.length - i))
     ;[array[i], array[swapIndex]] = [array[swapIndex], array[i]]
   }
-}
\ No newline at end of file
+}
diff --git a/common/src/util/string.ts b/common/src/util/string.ts
index 4dae265..23e1c73 100644
--- a/common/src/util/string.ts
+++ b/common/src/util/string.ts
@@ -4,4 +4,4 @@ export function removeEmojis(str: string) {
     /[\u{1F600}-\u{1F64F}\u{1F300}-\u{1F5FF}\u{1F680}-\u{1F6FF}\u{1F700}-\u{1F77F}\u{1F780}-\u{1F7FF}\u{1F800}-\u{1F8FF}\u{1F900}-\u{1F9FF}\u{1FA00}-\u{1FA6F}\u{1FA70}-\u{1FAFF}\u{2600}-\u{26FF}\u{2700}-\u{27BF}\u{2300}-\u{23FF}\u{2B50}\u{2B55}\u{2934}\u{2935}\u{2B05}\u{2B06}\u{2B07}\u{2B1B}\u{2B1C}\u{2B50}\u{2B55}\u{3030}\u{303D}\u{3297}\u{3299}\u{FE0F}]/gu,
     ''
   )
-}
\ No newline at end of file
+}
diff --git a/common/tsconfig.js b/common/tsconfig.js
new file mode 100644
index 0000000..e9bb67a
--- /dev/null
+++ b/common/tsconfig.js
@@ -0,0 +1,22 @@
+// hacky workaround for not being able to import tsconfig.json directly
+export default {
+  compilerOptions: {
+    rootDir: 'src',
+    composite: true,
+    module: 'commonjs',
+    moduleResolution: 'node',
+    noImplicitReturns: true,
+    outDir: 'lib',
+    tsBuildInfoFile: 'lib/tsconfig.tsbuildinfo',
+    sourceMap: true,
+    strict: true,
+    target: 'es2022',
+    skipLibCheck: true,
+    paths: {
+      'common/*': ['./src/*', '../lib/*'],
+    },
+    resolveJsonModule: true,
+    esModuleInterop: true,
+  },
+  include: ['src/**/*.ts'],
+}
diff --git a/common/tsconfig.json b/common/tsconfig.json
index 2506d8d..09eab2a 100644
--- a/common/tsconfig.json
+++ b/common/tsconfig.json
@@ -13,7 +13,9 @@
     "skipLibCheck": true,
     "paths": {
       "common/*": ["./src/*", "../lib/*"]
-    }
+    },
+    "resolveJsonModule": true,
+    "esModuleInterop": true
   },
   "include": ["src/**/*.ts"]
 }