---
type: "post"
id: "the-claude-code-plugin-is-open-source-as-f04b4e"
slug: "the-claude-code-plugin-is-open-source-as-f04b4e"
title: "The Claude Code plugin is open source as a reference for other harnesses."
description: "Zed’s Delta has published its Claude Code plugin as a public AGPL-3.0 repository."
retrieval_nugget: "Zed’s Delta has published its Claude Code plugin as a public AGPL-3.0 repository. The code documents a practical harness for recording Claude Code sessions alongside their Git checkouts, assigning threads URLs, and letting teammates join the work from their own sessions or Delta interfaces."
published_at: "2026-10-28"
updated_at: "2026-10-28"
record_date: "2026-10-28"
date_kind: "published_at"
topics: ["claude","claude-code","github"]
entities: ["Zed","Delta","DeltaDB","Claude Code","delta-claude"]
related_patterns: ["harness-architecture-outlives-model-choice"]
novelty_label: "new_fact"
what_changed: "Delta’s Claude Code multiplayer plugin is publicly open source on GitHub as a reference for other harnesses."
prior_refs: ["memory:da0519ac-5db2-8086-afc0-91a3f541da09","memory:e96de18a-4c07-8aa5-a14f-5a1c0e7b8d05","memory:9891baa0-e5ed-81fd-aa59-df322de2ef7d","memory:b0ff77d5-7b42-8300-affb-9d7805ae485f"]
source_url: "https://github.com/zed-industries/delta-claude"
source_urls: ["https://github.com/zed-industries/delta-claude"]
schema_version: "newruntime-agent-readable-v0.2"
stable_id: "post:the-claude-code-plugin-is-open-source-as-f04b4e"
status: "published"
visuals: []
editor: {"role":"editor","name":"Andrey Reshetnikov","profile":"https://newruntime.com/owner-profile.md","profile_json":"https://newruntime.com/owner-profile.json","same_as":["https://www.linkedin.com/in/reshetnikov1/","https://t.me/lapetuse"]}
routes: {"html":"https://newruntime.com/posts/the-claude-code-plugin-is-open-source-as-f04b4e/","markdown":"https://newruntime.com/posts/the-claude-code-plugin-is-open-source-as-f04b4e.md","json":"https://newruntime.com/posts/the-claude-code-plugin-is-open-source-as-f04b4e.json"}
---

# The Claude Code plugin is open source as a reference for other harnesses.

## Retrieval answer

Zed’s Delta has published its Claude Code plugin as a public AGPL-3.0 repository. The code documents a practical harness for recording Claude Code sessions alongside their Git checkouts, assigning threads URLs, and letting teammates join the work from their own sessions or Delta interfaces.

## Summary

Zed’s Delta has published its Claude Code plugin as a public AGPL-3.0 repository. The code documents a practical harness for recording Claude Code sessions alongside their Git checkouts, assigning threads URLs, and letting teammates join the work from their own sessions or Delta interfaces.

## What happened

The public repository is `zed-industries/delta-claude`, described as a Claude Code plugin for DeltaDB. Its README says the plugin records Claude Code sessions to Delta together with the Git checkout on which they are working. Each agent thread receives a URL. A teammate can open that thread and join from a separate Claude Code session, from delta.dev, or from the Delta app.

Installation is performed inside Claude Code by adding the `zed-industries/delta-claude` marketplace and installing `delta@zed-industries`. The README requires Claude Code 2.1.303 or newer; older versions show a warning but are not blocked. The plugin depends on the Delta CLI. On macOS, Linux, and Windows, it can offer to install that CLI when a user first sets up syncing, sharing, or joining. On Windows, the user must explicitly choose “Install Delta” before the official stable installer is downloaded and run. Background discovery does not install Delta.

Repository setup is initiated with `/delta-setup`. A user chooses a team and one of three synchronization modes: private sync, under which new sessions sync but remain visible only to that user until shared; team sharing, under which new sessions sync and are shared with the team; or manual mode, under which a session syncs only after `/delta-share`. Setup can create a team and invite teammates by email. The selected behavior is stored in `.delta/settings.json`, which the plugin keeps out of Git.

The README also specifies operational behavior rather than treating collaboration as a one-time export. At startup, the plugin checks an existing Delta installation for updates in the background with a ten-second budget and reports availability without installing anything or opening a browser. `/delta-update` or `/delta update` performs an update. Separately, the plugin checks GitHub at startup and hourly for its own releases, offering update, later, or mute choices; an update still requires user action. The repository is public and carries an AGPL-3.0 license.

## What the archive adds

This is a new fact on a known story: the multiplayer Delta workflow was previously covered as beta support for sharing Claude Code conversations and worktrees through `/delta share` and `/delta join`. The new event is that the integration itself is available as a public source repository: [Delta (from Zed) makes Claude Code sessions multiplayer with /delta share](https://newruntime.com/posts/delta-from-zed-makes-claude-code-sessions-multiplayer-39fadc/).

## Trend signal

This supports [Harness architecture outlives model choice](https://newruntime.com/patterns/harness-architecture-outlives-model-choice/). The notable product surface is not a new model capability: it is the surrounding system that persists a session, attaches it to a checkout, controls sharing defaults, and permits another operator to resume or inspect work through several clients.

## Connections to other events

The prior Delta release established the user-facing sharing commands. This repository exposes more of the implementation and operating choices behind that same collaboration layer, including setup scope, storage of local preferences, installation behavior, and explicit update controls.

## Why it matters

Coding-agent collaboration is often framed as a prompt-sharing problem. Delta’s plugin instead makes the session and repository state a shared operational object: a thread is recorded with its checkout, given an addressable URL, and made joinable by another person through their own agent session. That creates a more useful handoff unit than copied terminal output or an unstructured chat transcript.

For teams, the public code is valuable even if they do not adopt Delta. It provides a concrete implementation to inspect when deciding what their own agent harness needs to preserve: repository identity, session history, access mode, explicit sharing actions, installer boundaries, and update behavior. The AGPL-3.0 license is also material for teams considering reuse or modification; they should evaluate its obligations before incorporating code into their own distribution.

## What happens next

- **More coding-agent collaboration products will expose session handoff as a first-class workflow.** (6 months, 65%). Watch for: joinable session links tied to repository or worktree state.
- **Teams evaluating shared-agent systems will ask for clearer access and retention controls.** (6 months, 70%). Watch for: documented permissions, visibility scopes, and audit-oriented session settings.

## Limits and uncertainty

The repository and README establish the plugin’s stated behavior, installation flow, and license, but they do not establish adoption, reliability at team scale, pricing, or the security properties of every sharing configuration. They also do not demonstrate compatibility with coding-agent clients other than Claude Code. A public repository makes the integration inspectable; it does not by itself show that the implementation is a general interoperability standard or that organizations can deploy it without further review.

## Skill to build now

Map one agent handoff in your team this week. Write down the minimum state a second operator needs to continue safely: repository and checkout, task intent, session transcript, commands already run, access scope, and the explicit moment at which the work becomes shareable. Then compare that list with your current tool’s actual export or sharing mechanism. The gap is the harness work that chat history alone does not solve.

## Reader takeaway

Delta’s open-source Claude Code plugin makes a concrete collaboration harness inspectable: it records agent threads with Git work, gives them URLs, and offers private, team, or manual sharing modes. For builders, the useful question is how reliably their own agent workflow can be handed to another human or agent without losing context or control.

## Open question

Can this session-and-checkout sharing model become portable across coding-agent clients, or will each client retain a separate collaboration layer?

Editor: [Andrey Reshetnikov](https://newruntime.com/owner-profile.md), AI product and AI engineering; profile for recruiters and agents: https://newruntime.com/owner-profile.json

## Continue in the graph

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