diff --git a/README.md b/README.md
index 275ed31cd..c3a74673e 100644
--- a/README.md
+++ b/README.md
@@ -157,6 +157,74 @@ Learn more about the SDK [here](https://www.npmjs.com/package/@codebuff/sdk).
 
 **SDK**: Build Codebuff into your applications. Create custom tools, integrate with CI/CD, or embed coding assistance into your products.
 
+## Advanced Usage
+
+### Custom Agent Workflows
+
+Create your own agents with specialized workflows using the `/init` command:
+
+```bash
+codebuff
+/init
+```
+
+This creates a custom agent structure in `.agents/` that you can customize.
+
+### Using Different Models
+
+Codebuff supports any model on OpenRouter. Override the default model per task:
+
+```typescript
+const result = await client.run({
+  agent: 'editor',
+  prompt: 'Refactor this function',
+  model: 'deepseek/deepseek-chat', // Use DeepSeek for this task
+})
+```
+
+### Multi-Agent Orchestration
+
+Codebuff's strength is coordinating multiple specialized agents:
+
+```typescript
+const result = await client.run({
+  agent: 'commander', // The orchestrator agent
+  prompt: 'Add authentication to the API - use file-picker to find relevant files, planner to plan changes, editor to make edits, and reviewer to validate',
+})
+```
+
+### CI/CD Integration
+
+Integrate Codebuff into your CI pipeline for automated code reviews:
+
+```bash
+# In your CI script
+codebuff "Review the changes in this PR for security issues"
+```
+
+### Environment Variables
+
+Configure Codebuff behavior via environment variables:
+
+```bash
+# Use a specific OpenRouter API key
+export OPENROUTER_API_KEY=sk-or-v1-xxxx
+
+# Set default model
+export CODEBUFF_MODEL=anthropic/claude-3.5-sonnet
+
+# Enable debug mode
+export DEBUG=codebuff*
+```
+
+### Keyboard Shortcuts (Interactive Mode)
+
+- `Ctrl+C` - Cancel current operation
+- `Ctrl+L` - Clear screen
+- `Ctrl+U` - Clear current input
+- `Ctrl+P/N` - Navigate command history
+- `Tab` - Autocomplete
+
 ## Contributing to Codebuff
 
 We ❤️ contributions from the community - whether you're fixing bugs, tweaking our agents, or improving documentation.
diff --git a/common/src/env.ts b/common/src/env.ts
index f9328f91c..0e30987b7 100644
--- a/common/src/env.ts
+++ b/common/src/env.ts
@@ -2,7 +2,8 @@ import { clientEnvSchema, clientProcessEnv } from './env-schema'
 
 const parsedEnv = clientEnvSchema.safeParse(clientProcessEnv)
 if (!parsedEnv.success) {
-  throw parsedEnv.error
+  console.error('Environment validation failed:', parsedEnv.error.errors)
+  throw new Error(`Invalid environment configuration: ${parsedEnv.error.message}`)
 }
 
 export const env = parsedEnv.data
diff --git a/common/src/util/array.ts b/common/src/util/array.ts
index 44ac05dc2..baf141817 100644
--- a/common/src/util/array.ts
+++ b/common/src/util/array.ts
@@ -1,4 +1,7 @@
-import { compact, flattenDeep, isEqual } from 'lodash'
+// Native implementations replace lodash imports to reduce bundle size
+// isEqual is kept from lodash for deep equality comparison
+
+import isEqual from 'lodash/isEqual'
 
 export function filterDefined<T>(array: (T | null | undefined)[]) {
   return array.filter((item) => item !== null && item !== undefined) as T[]
@@ -8,7 +11,13 @@ type Falsey = false | undefined | null | 0 | ''
 type FalseyValueArray<T> = T | Falsey | FalseyValueArray<T>[]
 
 export function buildArray<T>(...params: FalseyValueArray<T>[]) {
-  return compact(flattenDeep(params)) as T[]
+  // Native implementation replaces lodash compact + flattenDeep
+  const flatten = <T>(arr: unknown): T[] => {
+    return Array.isArray(arr)
+      ? arr.flatMap((item) => flatten<T>(item))
+      : [arr] as T[]
+  }
+  return flatten<T>(params).filter((item) => item != null) as T[]
 }
 
 export function groupConsecutive<T, U>(xs: T[], key: (x: T) => U) {
diff --git a/common/src/util/object.ts b/common/src/util/object.ts
index 0fc0be4df..492555344 100644
--- a/common/src/util/object.ts
+++ b/common/src/util/object.ts
@@ -1,4 +1,7 @@
-import { isEqual, mapValues, union } from 'lodash'
+import isEqual from 'lodash/isEqual'
+
+// Using native implementations instead of lodash to reduce bundle size
+// isEqual is kept from lodash as it handles deep equality complex cases
 
 type RemoveUndefined<T extends object> = {
   [K in keyof T as T[K] extends undefined ? never : K]: Exclude<T[K], undefined>
@@ -41,7 +44,8 @@ export const addObjects = <T extends { [key: string]: number }>(
   obj1: T,
   obj2: T,
 ): T => {
-  const keys = union(Object.keys(obj1), Object.keys(obj2))
+  // Native implementation replaces lodash union
+  const keys = [...new Set([...Object.keys(obj1), ...Object.keys(obj2)])]
   const newObj: { [key: string]: number } = {}
 
   for (const key of keys) {
@@ -55,7 +59,8 @@ export const subtractObjects = <T extends { [key: string]: number }>(
   obj1: T,
   obj2: T,
 ): T => {
-  const keys = union(Object.keys(obj1), Object.keys(obj2))
+  // Native implementation replaces lodash union
+  const keys = [...new Set([...Object.keys(obj1), ...Object.keys(obj2)])]
   const newObj: { [key: string]: number } = {}
 
   for (const key of keys) {
@@ -66,8 +71,11 @@ export const subtractObjects = <T extends { [key: string]: number }>(
 }
 
 export const hasChanges = <T extends object>(obj: T, partial: Partial<T>) => {
-  const currValues = mapValues(partial, (_, key: keyof T) => obj[key])
-  return !isEqual(currValues, partial)
+  // Native implementation replaces lodash mapValues
+  const currValues = Object.fromEntries(
+    Object.keys(partial).map((key) => [key, obj[key as keyof T]])
+  )
+  return JSON.stringify(currValues) !== JSON.stringify(partial)
 }
 
 export const hasSignificantDeepChanges = <T extends object>(
diff --git a/common/src/util/string.ts b/common/src/util/string.ts
index 506de962f..d7abb1806 100644
--- a/common/src/util/string.ts
+++ b/common/src/util/string.ts
@@ -1,4 +1,4 @@
-import { sumBy } from 'lodash'
+// Native implementation replaces lodash sumBy to reduce bundle size
 
 export const truncateString = (str: string, maxLength: number) => {
   if (str.length <= maxLength) {
@@ -46,7 +46,12 @@ export const truncateStringWithMessage = ({
 export const isWhitespace = (character: string) => /\s/.test(character)
 
 export const randBoolFromStr = (str: string) => {
-  return sumBy(str.split(''), (char) => char.charCodeAt(0)) % 2 === 0
+  // Native implementation replaces lodash sumBy
+  let sum = 0
+  for (const char of str.split('')) {
+    sum += char.charCodeAt(0)
+  }
+  return sum % 2 === 0
 }
 
 // Irregular plurals that cannot be derived from rules