DeepSeek Harness v0.2.1-rc.1

DeepSeek Harness v0.2.1-rc.1: Plugins, Context & Migration

Author
DeepSeekAgent.io Editorial Team
Published
Updated

DeepSeek Harness v0.2.1-rc.1 is the first release candidate in the 0.2.1 line. It consolidates plugin, model, Session, workspace, and context features introduced across the preceding alphas. Its significance is not one headline feature, but a broad set of interfaces and behaviors approaching a release boundary.

Status and installation

npx @deepseek-ai/[email protected] web

At publication, npm latest still points to 0.2.0-rc.2. Pin rc.1 or use next for candidate testing, and keep prerelease Profiles separate from production data.

A complete plugin workflow

The 0.2.1 line adds custom plugin sources, Agent-assisted plugin creation, dependency synchronization, and hot reload. Minimal can load optional plugins, while Claude Code and Codex bundles expand compatibility. The experimental Claude Code Mods bridge offers a migration route, but native DSH Plugins retain the fuller lifecycle and capability model.

Compatibility primarily uses engines.dsh. Internal plugins should declare a supported range and test installation, enable/disable, dependency setup, reload, and uninstall—not merely whether the package appears in a list.

Models, tools, and context

Custom models can declare reasoning levels. Dynamic tools and system-prompt updates reduce fixed state in long Sessions. Minimal gains image reading and automatic compaction, with /compact available as a manual control. Subagents can use independent Presets, and wait behavior is improved.

These changes affect the token curve of long tasks. Measure context size before and after compaction, tool-set changes, parent/child Session usage, and the provider's actual billed usage.

Workspaces, remote use, and SDKs

The candidate adds working-directory tools and SDK support, an SSH helper runtime, Git Worktrees, and richer Session state APIs. The shared AGENTS.md location also changes. Include SDK resume, Remote connections, Headless execution, and shared instruction discovery in migration tests.

Web deployment work covers --public-url, IPv4/IPv6, and TLS. A reverse-proxy test must include path prefixes, WebSockets, cookies, and trusted hosts—not just a successful page load.

Migration checklist

  • Web/Desktop saved credentials differ from Headless environment or .env configuration.
  • Old invariant exports are removed.
  • Plugin subpath metadata and engines.dsh require attention.
  • Statistics split into activity and usage.
  • Agent Team Inbox APIs change.
  • Python PTC uses a revised sandbox boundary, and the old both mode is removed.
  • Azure provider naming changes.
  • SDK resume, public URL, and listener options require retesting.

Plugin, Remote/Headless, long-Session, and multi-agent users have the strongest reason to test rc.1 in an isolated Profile. Users who only need a stable Web UI can remain on npm latest until 0.2.1 reaches that channel.

References