claude-code - 💡(How to fix) Fix [FEATURE] Feature request: Session start hook or --init-command CLI flag for automatic setup on launch [1 participants]

Preflight Checklist

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

Problem Statement

Summary

I'd like the ability to automatically run a slash command (or shell command) when a Claude Code session starts, optionally conditioned on the working directory.

Current Limitation

• Available hooks (PreToolUse, PostToolUse, Notification) only fire during tool execution, not on session start.
• There's no CLI flag to inject an initial command into an interactive session.
• Shell wrappers (<<<, expect) are fragile and break interactive stdin.

Proposed Solution

Proposed Solutions (any one would work)

1. SessionStart hook type — fires once when a session begins, with access to cwd for conditional logic:

   {                                                                                                            
     "hooks": {                                                                                                 
       "SessionStart": [                                                                                        
         {                                                                                                      
           "matcher": { "cwd_pattern": "/my/sandbox/dir/abc/.*" },                                          
           "commands": ["/sandbox"]                                                                             
         }                                                                                                      
       ]                                                                                                        
     }                                                                                                          
   }

2. CLI flag like --init-command "/sandbox" that executes a slash command after interactive startup completes.
3. startup_commands field in .claude/settings.json that lists slash commands to run on launch:
   {
   "startup_commands": ["/sandbox"]
   }

Alternative Solutions

No response

Priority

Medium - Would be very helpful

Feature Category

CLI commands and flags

Use Case Example

Use Case

I work across multiple project trees. When launching Claude from directories under a specific path (e.g.,
/my/sandbox/dir/abc/), I need /sandbox to run automatically to configure the session environment. Currently I have to remember to type it manually every time.

Additional Context

No response