[BUG] Prompt-based Stop hooks receive only metadata, not conversation content (regression confirmed in v2.0.42)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Prompt-based Stop hooks are unable to access conversation content for evaluation. The hook receives session metadata but the LLM cannot read the actual transcript, making content-aware evaluation impossible.

What Should Happen?

Related Issue: This appears to be the same regression reported in GitHub issue for v2.0.37
(teren-papercutlabs)

Configuration (in ~/.claude/settings.json):
```
{
"hooks": {
"Stop": [
{
"hooks": [
{
"type": "prompt",
"prompt": "You are analyzing a Claude Code conversation... Context: $ARGUMENTS...
[evaluation criteria]",
"timeout": 60
}
]
}
]
}
}

  Expected Behavior:
  Based on documentation example ("Analyze the conversation and determine if..."), $ARGUMENTS
  should contain conversation content that the LLM can evaluate.

  Actual Behavior:
  - Hook receives only metadata: session_id, transcript_path, cwd, permission_mode,
  hook_event_name, stop_hook_active
  - LLM correctly identifies: "Cannot evaluate - transcript file is not accessible to this
  evaluation context"
  - The transcript_path is provided but the LLM cannot read files

  Error Output:
  Prompt hook condition was not met: Cannot evaluate criteria - transcript file is not
  accessible to this evaluation context. The hook receives only session metadata... but cannot
  read the actual transcript file at the provided path.

  Impact:
  All prompt-based Stop hooks requiring conversation analysis are non-functional. This blocks
  use cases like learning pattern detection, quality control, and style enforcement.

  Documentation Inconsistency:
  The official example implies conversation is accessible ("Analyze the conversation"), but
  implementation only provides file path without content.

### Error Messages/Logs

```shell
Prompt hook condition was not met: Cannot evaluate criteria - transcript file is not accessible to this evaluation context. The hook receives only session metadata... but cannot read the actual transcript file at the provided path.

Steps to Reproduce

1. Add Stop hook to ‎⁠~/.claude/settings.json⁠:

{

"hooks": {

"Stop": [

{

"hooks": [

{

"type": "prompt",

"prompt": "Analyze the conversation context: $ARGUMENTS\n\nCheck if all tasks are\n complete.\n\nRespond with JSON: {\"decision\": \"approve\" or \"block\", \"reason\": \"explanation\"}",

"timeout": 30

}

]

}

]

}

}

1. Start a new Claude Code session: ‎⁠claude⁠

1. Send a message that triggers a response (e.g., “Hello” or a simple task).

1. Observe the error output when the Stop hook fires.

1. Error appears: “Prompt hook condition was not met: Cannot evaluate - transcript file is not accessible to this evaluation context…”

What the LLM receives{

"session_id": "...",

"transcript_path": "/path/to/transcript.jsonl",

"cwd": "...",

"hook_event_name": "Stop",

"stop_hook_active": true

}

The model receives only metadata, not the actual conversation content required for evaluation.

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.0.42

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

_No response_