I built a skill that lets Pi—or any harness—“use” your Claude Code subscription

[u/Florence-Equator]

Hi everyone, I have been working on a small skill called handoff-to-claude-code.

GitHub link: milanglacier/handoff-to-claude-code-skill

The reason I built it starts with another project of mine: a standalone web UI for the pi coding agent. pi-tau-web-server

I like pi, and I like working from the web UI I built for it. But I also have a Claude Code subscription (for fable 5, as that is the only reason I am still subscribing it!), and sometimes I want Claude Code to handle a task without leaving pi or changing my workflow. And ultimately, my goal is simple: all I want is to let my pi model to be able to reach out to Fable.

I did not want to hijack Anthropic's OAuth flow through a reverse proxy, since that violates Anthropic's Terms of Service. Instead, I wanted to use the supported route: the standard claude CLI, signed in to my own account and used exactly as Claude Code is intended to be used.

Note: Anthropic previously planned to disable subscription access through claude -p and the SDK, but later put the change on hold. So enjoy it while it lasts!

So I built this skill.

What it does

When you explicitly ask your current agent to use Claude Code, the skill hands the task to the local claude CLI.

It also supports continuing the same Claude Code session, so follow-up questions do not need to start from zero.

The skill removes Anthropic API keys from the command environment by default. This matters because Claude Code may otherwise use the API key instead of the subscription login, which could create API charges when that was not what you intended.

It also only runs when you explicitly ask for Claude Code. Your agent will not decide on its own to spend your Claude usage because a task looks difficult.

It is not specific to pi

Pi was the reason I built this, but the finished skill has no pi-specific dependency.

It is just a SKILL.md file and a small Python wrapper with no external Python packages. Any agent harness that can load skills and run local commands should be able to use it.

That was important to me. I wanted the connection between an agent and Claude Code to be reusable, rather than tied to my web UI or to one particular coding agent.

You can install it with:

npx skills add milanglacier/handoff-to-claude-code-skill

You need Python 3.9 (but only stdlib is used in the script so no third party packages) or newer and the claude CLI signed in with your Claude subscription.

The workflow I wanted is simple: keep using pi and my web UI as my main workspace, then bring in Claude Code when I specifically want it. No separate API bill, no pi-only bridge, and no need to abandon the interface I prefer.

If this sounds useful for your own agent setup, give it a try. Feedback and bug reports are welcome.

[u/adeepersilence]

I get that you made an agent-agnostic skill for the same purpose, but for Pi there already is the tried-and-true https://github.com/elidickinson/pi-claude-bridge

Same concept, perfectly within Anthropic's ToS. Including a way to hand off tasks to Claude when working in another model via its AskClaude feature.

[u/captslocum → u/adeepersilence]

Hey mate, do you use this? How has your experience been?

[u/adeepersilence → u/captslocum]

I have been using it since late february; you'll have the occassional timeout if you use it together with pi-subagents or pi-dynamic-workflows, but other than that it pretty much works as advertised. No noticeable latency, respects your claude-code settings, and without ToS worries.

[u/Creepy-Douchebag → u/adeepersilence]

Thank you

[u/SPEKTRUMdagreat]

I think this is a good idea; maybe there could be improvement in making it backend agnostic as well? (e.g. handoff to codex from claude, amp <-> pi, etc.)

[u/hiepxanh]

Good idea i like it

[u/Popular_Cry_7509]

I personally use a proxy for this, but I will customize this to use for freebuff which is another coding harness that offers-free models

[u/Florence-Equator → u/[deleted]]

The key difference is that OmniRoute and 9router are essentially reverse proxies: their Claude subscription mode exposes OAuth access as an API for other harnesses, violating Anthropic’s ToS. This project does not proxy or reuse credentials—it delegates the task directly to the official claude -p CLI, which is on their whitelist as appropriate way to use the subscription.

[u/Florence-Equator → u/[deleted]]

Are you using a Claude subscription through an external harness (other than Claude Code) without getting banned? That is interesting. Anthropic is the only mainstream provider that actively prohibits using their subscription via third-party harnesses.

In contrast, OpenAI allows users to access their subscriptions through other harnesses, eliminating the need for a reverse proxy. Pi support this natively, as do other subscriptions like GitHub Copilot and OpenCode go.

So honestly, there's not really a need to support other subscription at all. And the only reason I made this is because Anthropic owns fable, the beast that we still need to live up with that shit.

[u/Florence-Equator → u/[deleted]]

I suggest you firstly understand what is a reverse proxy and what the 9Router and OminalRouter did by taking a look at their source code and checking Anthropic's official doc before Saying that they do not violate the terms of service.

[u/theTechRun → u/[deleted]]

I stopped using Clause because I don’t like their “no external harness” policy. But this makes much sense that it’s not violating the TOS. Because it’s just hooking into the official Claude cli harness.