[FEATURE] Feature Request: Display startup hook stdout output in terminal

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

---
GitHub Issue for Claude Code

URL to report: https://github.com/anthropics/claude-code/issues

Issue Title

Feature Request: Display startup hook stdout output in terminal

Issue Description

Problem

Startup hooks (SessionStart) execute successfully but their stdout output is not displayed in the PowerShell
terminal when Claude Code starts. The output is captured internally and visible to Claude in system messages, but
not shown to the user.

Current Behavior

PS C:\Users\KhurshidAli\VibeCodingGenesys> claude

▐▛███▜▌ Claude Code v2.0.33
▝▜█████▛▘ Sonnet 4.5 (1M context) · API Usage Billing
▘▘ ▝▝ C:\Users\KhurshidAli\VibeCodingGenesys

# Chat starts immediately - no hook output visible

Expected Behavior

PS C:\Users\KhurshidAli\VibeCodingGenesys> claude

▐▛███▜▌ Claude Code v2.0.33
▝▜█████▛▘ Sonnet 4.5 (1M context) · API Usage Billing
▘▘ ▝▝ C:\Users\KhurshidAli\VibeCodingGenesys

================================================================================
🤖 GENESYS CLOUD AGENT - ACTIVATED
================================================================================

📍 Connected to: aafsdfsa
Region: agfsergreg
Org ID: bfadbsndfndtjyzsdASvfbxdgfngfuknb

👤 Authenticated as: .ClaudeCode_Exploration_Khurshid

🚀 INSTANT CAPABILITIES
--------------------------------------------------------------------------------
✓ User Management → List, create, search users
✓ Queue Management → List, create queues
...

# Then chat starts

Configuration

.claude/settings.local.json:
{
"hooks": {
"SessionStart": [
{
"hooks": [
{
"type": "command",
"command": "python python_scripts/startup_welcome.py"
}
]
}
]
}
}

Use Case

I'm building a domain-specific agent skill (Genesys Cloud operations) and want users to see:

• Which environment/org they're connected to
• Available capabilities
• Quick start examples
• Authentication status

This welcome banner provides immediate context without requiring the user to ask "what can you do?"

Verification

• ✅ Hook executes successfully (confirmed via Claude's system messages)
• ✅ Script works when run manually: python python_scripts/startup_welcome.py
• ✅ Script outputs to stdout correctly
• ❌ Output not displayed in terminal on startup

Environment

• Claude Code version: v2.0.33
• Platform: Windows 11
• Shell: PowerShell 7.5.4
• Model: Sonnet 4.5 (1M context)

Workarounds Tried

1. Using echo commands in hooks - same issue
2. Using skill auto-activation to show banner in first response - works but not as immediate
3. Creating slash command - works but requires manual invocation

Feature Request

Please add an option to display startup hook stdout/stderr in the terminal, either:

Option A: Always display hook output before chat starts
{
"hooks": {
"SessionStart": [
{
"hooks": [
{
"type": "command",
"command": "python script.py",
"displayOutput": true // NEW
}
]
}
]
}
}

Option B: Global setting to show all hook output
{
"displayHookOutput": true, // NEW
"hooks": { ... }
}

Option C: Hook-specific visibility levels
{
"hooks": {
"SessionStart": [
{
"hooks": [
{
"type": "command",
"command": "python script.py",
"outputMode": "terminal" // NEW: "terminal" | "context" | "hidden"
}
]
}
]
}
}

Impact

This would greatly improve user experience for:

• Custom agent skills with context-specific capabilities
• Environment/project-specific tooling information
• Authentication/connection status displays
• Quick reference information on startup

---

Proposed Solution

PS C:\Users\KhurshidAli\VibeCodingGenesys> claude

▐▛███▜▌ Claude Code v2.0.33
▝▜█████▛▘ Sonnet 4.5 (1M context) · API Usage Billing
▘▘ ▝▝ C:\Users\KhurshidAli\VibeCodingGenesys

================================================================================
🤖 GENESYS CLOUD AGENT - ACTIVATED
================================================================================

📍 Connected to: aafsdfsa
Region: agfsergreg
Org ID: bfadbsndfndtjyzsdASvfbxdgfngfuknb

👤 Authenticated as: .ClaudeCode_Exploration_Khurshid

🚀 INSTANT CAPABILITIES
--------------------------------------------------------------------------------
✓ User Management → List, create, search users
✓ Queue Management → List, create queues
...

# Then chat starts

Alternative Solutions

Give option to customize the starting screen project folder specific.

Priority

Medium - Would be very helpful

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_