[FEATURE] Add --ephemeral flag to prevent saving conversation history in programmatic mode

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

When running Claude Code programmatically with claude -p "Something", a conversation history is always created as a .jsonl file. This conversation then appears when running claude --resume, cluttering the conversation history with automated/scripted runs.

For CI/CD pipelines, automated scripts, and one-off programmatic queries, these ephemeral conversations should not persist in the resume history. Currently, there's no way to prevent this behavior.

Proposed Solution

Add an --ephemeral flag that prevents conversation history from being saved to disk.

Example usage:

# One-off programmatic query - no history saved
claude -p --ephemeral "Analyze this log file" < logs.txt

# CI/CD pipeline - don't clutter history
claude -p --ephemeral "Run linting and fix issues" --output-format json

The flag should:

1. Skip creating the .jsonl conversation file
2. Prevent the session from appearing in claude --resume
3. Skip background conversation summarization jobs

[!NOTE] This flag should only work with --print mode since interactive sessions inherently expect persistence.

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<summary><strong>Alternative Solutions</strong></summary>

Current workarounds:

1. Post-execution cleanup: Parse session_id from JSON output and manually delete the .jsonl file

• Brittle and requires knowing the file location
• May conflict with background summarization jobs

Alternatives considered:

1. Environment variable: CLAUDE_EPHEMERAL=1 - less discoverable than a CLI flag
2. Auto-cleanup after N days - doesn't solve the immediate clutter problem

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Priority

High - Significant impact on productivity

Feature Category

CLI commands and flags

Use Case Example

CI/CD Pipeline:

# In GitHub Actions workflow
claude -p --ephemeral "Review PR for security issues" \
  --output-format json --allowedTools Read,Grep > review.json

Automated Monitoring:

# Runs every hour via cron - would create 24+ conversations/day
echo "$logs" | claude -p --ephemeral "Detect anomalies" --output-format json

Quick Development Queries:

claude -p --ephemeral "Explain this error" < error.log

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<summary><strong>Additional Context</strong></summary>

Related documentation:

• Conversation history is always stored: https://docs.anthropic.com/en/docs/claude-code/common-workflows
• No mention of ephemeral mode: https://docs.anthropic.com/en/docs/claude-code/headless

Similar features in other tools:

• Docker: docker run --rm (ephemeral containers)
• Git: git commit --no-verify (skip hooks)

Implementation considerations:

• Should be mutually exclusive with --continue and --resume
• Should work with all output formats (text, json, stream-json)

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