clarp: Open Source Drop-In Replacement for Claude -p Before June 15 Metered Pricing

Claude -p (print mode) and the Agent SDK are moving to separate credit-based pricing on June 15. For developers with tools and workflows built around claude -p, that change could mean significantly higher costs. Enter clarp — an open source CLI that acts as a drop-in replacement for claude -p in local developer workflows.

How It Works

Under the hood, clarp launches the normal interactive Claude Code CLI in a hidden PTY, then uses a local read-only proxy to observe the Anthropic API stream and reconstruct claude -p-style output. It does not modify Claude's requests or responses — it's purely a proxy that translates interactive output into print-mode format.

In most projects, migrating is as simple as changing the binary name from claude to clarp.

What Works

• Text, JSON, and stream-JSON output
• stdin prompts
• Multi-turn stream-JSON input
• Most Claude Code flag passthrough
• Permission forwarding
• Token-level partials via --include-partial-messages

What's Not Yet Perfect

Sideband/non-assistant events are not exact parity. Some hook/task/progress events are still incomplete. The author says it's high parity for common claude -p use but not a perfect reimplementation of Claude Code's internal print-mode pipeline. It is aimed at local developer workflows, not a hosted service.

Installation

npm install -g clarp-cli

Once installed, replace claude -p with clarp in your scripts and tools. The project is built with significant help from Claude itself: implementing the proxy/session pieces, writing parity tests, finding edge cases in argument parsing, and tightening the release and docs.

Who It's For

Developers who have automated tools or scripts dependent on claude -p and want to avoid the upcoming metered pricing without rewriting their workflows.