Han: For the Solo Product Engineer

Han is a suite of AI skills and agents for solo (or small-team) product engineers. It combines evidence-based planning, test-driven implementation, full documentation maintenance, deep code review, and architectural analysis into a team of specialists you can dispatch from Claude Code.

What this plugin does

Han turns planning, implementation, review, and documentation work that would normally take a team into a set of deterministic skills you run from Claude Code.

Each skill dispatches specialist agents, such as project managers, adversarial reviewers, investigators, architectural analysts, and testing and security specialists, to do the judgment-heavy work. It then folds their findings into an artifact you can trust.

The skills are designed to compose. You can plan a feature, then plan its implementation, then iterate on the plan, then build it test-first, then review the resulting code, then write the PR description. All through named skills that hand off to each other cleanly.

Read Concepts for the skill-and-agent model that runs through the whole plugin.

For Solo Product Engineers and Small Teams

Han is purpose-built for solo product engineers and small teams, instead of large teams or enterprise. This does not mean it can't work in larger teams, though. Read about why Han's focus is solo product engineers and small teams to understand Han's positioning and what it does not bring to the table.

Installation

Claude Code

Add the Test Double skills marketplace to Claude Code, then install the plugin:

/plugin marketplace add testdouble/han
/plugin install han@han

Han ships as multiple plugins:

Plugin	Type	What it brings
`han`	parent	the parent plugin that brings in `han-core`, `han-planning`, `han-coding`, `han-github`, and `han-reporting`
`han-core`	bundled	research, analysis, and documentation skills plus every agent
`han-planning`	bundled	planning skills you reach for before implementation
`han-coding`	bundled	coding skills you reach for while working in code
`han-github`	bundled	GitHub-facing skills like posting a code review on a PR
`han-reporting`	bundled	reporting skills like the stakeholder summary
`han-feedback`	opt-in	skill for capturing post-session feedback on Han skill runs
`han-atlassian`	opt-in	skills for publishing docs and work items to Atlassian products
`han-linear`	opt-in	skill for publishing work items to Linear (requires a Linear MCP server)
`han-plugin-builder`	opt-in	carries the guidance and skills for building your own skills, agents, and plugins

Installing han@han pulls in the bundled suite (the meta-plugin plus han-core, han-planning, han-coding, han-github, and han-reporting), and is the right choice for most people. If you do not want the planning, coding, GitHub, or reporting skills, install han-core@han instead, and add other specific plugins as desired.

For the full picture and a quick "which one do you need?" guide, see Choosing a Han plugin.

Codex

Add this repo as a Codex marketplace:

codex plugin marketplace add testdouble/han

Codex does not yet support meta-plugins like han@han (see openai/codex#23531,) so install the Han packages directly:

codex plugin add han-core@han
codex plugin add han-planning@han
codex plugin add han-coding@han
codex plugin add han-github@han
codex plugin add han-reporting@han

Install han-feedback, han-atlassian, han-linear, or han-plugin-builder separately when you want those opt-in packages.

Documentation

Concepts. Skill vs. agent, and how they compose. Read once before using the plugin.
Choosing a Han plugin. The full suite vs. core only, the han-planning, han-coding, han-github, and han-reporting dependencies on han-core, and a quick guide to which one to install.
Quickstart. Five paths for five common situations. Each path is a short sequence of skills.
Skills Index. All skills, grouped by purpose.
Agents Index. All agents, grouped by role.
Sizing. The small / medium / large model that decides how many agents the swarming skills dispatch.
YAGNI. The evidence-based "You Aren't Gonna Need It" rule every planning, review, and architecture skill applies.
Evidence. What counts as evidence in Han, how to characterize how strong it is, and what to do when no evidence exists at all.
Readability. The shared output standard every reader-facing skill applies as it writes, so its human-facing deliverable leads with the main point and reads consistently across skills.
Changelog. What's new in each version of the plugin.

How-To Guides

How-to guides. End-to-end recipes for planning a feature, revising a plan after the build starts, accelerating your understanding of unfamiliar code, triaging and investigating a bug, running an effective code review, and researching a decision. Pick one when you want the full walkthrough, not only the path.
How to provide feedback on Han. Send the maintainers structured feedback on a skill or agent run.
Extend Han via dependencies. Add your own custom skills on top of Han.
Build a plugin that depends on Han. Ship a plugin that builds on Han's skills and agents.

Contributing to Han

Contributing. Adding or editing skills, agents, and documentation.
Create a new skill. Build a new slash command from scratch with /skill-builder.
Create a new agent. Build a new subagent from scratch with /agent-builder.

Maintenance and Support

Maintenance horizon: Indefinitely maintained, best-effort. No SLA.
Project type: Personal project, with some Test Double support
How to report issues: GitHub Issues, with expected best effort for response within 2 weeks.

Han is an open source product of Test Double, and maintained by the following people:

River Lynn Bailey: Creator, and primary maintainer
Tamika Nomara: Core contributor
Aaron Frerichs: Core contributor
All contributors: Misc and greatly appreciated!

Name	Description	Category	Source
han	Meta-plugin that installs the bundled Han suite. Has no components of its own; it depends on han-core, han-planning, han-coding, han-github, and han-reporting so installing it pulls them all in. Does not bundle the opt-in han-feedback, han-atlassian, or han-plugin-builder plugins.	—	./han
han-core	Evidence-based research, architecture, and documentation skills for software projects, plus the adversarial specialist agents the rest of the suite dispatches. Includes issue triage, open-ended research, architectural decision records (ADRs), gap analysis, project discovery, project and feature documentation, and runbooks. Feature- and implementation-planning skills live in han-planning, which depends on han-core.	—	./han-core
han-planning	Planning skills for the Han suite: specifying, planning, sequencing, breaking down, and stress-testing work before implementation. Home of plan-a-feature, plan-implementation, plan-a-phased-build, plan-work-items, and iterative-plan-review. Depends on han-core; bundled by the han meta-plugin.	—	./han-planning
han-coding	Code-writing and execution skills for the Han suite. Home of the tdd skill, which drives a feature or behavior through a BDD-framed red-green-refactor loop with an enforced observed-failure gate. Depends on han-core; bundled by the han meta-plugin.	—	./han-coding
han-github	GitHub-specific extensions to Han. Provides skills to post code reviews as PR comments, update a PR description with a consistent format, and other GitHub-facing workflows.	—	./han-github
han-reporting	Reporting and summary skills for the Han suite. Turns feature specifications into plain-language stakeholder summaries (also called executive or business summaries) with diagrams, for sharing with non-technical stakeholders before implementation kicks off.	—	./han-reporting
han-feedback	Post-session feedback skill for the Han suite. Captures structured observations, ratings, and improvement ideas on the Han skills you ran in a session and optionally posts them as a GitHub issue to testdouble/han. Opt-in: installed on its own, not pulled in by the han meta-plugin.	—	./han-feedback
han-atlassian	Atlassian-facing extensions to the Han suite. Adds markdown-to-confluence, which publishes a local Markdown file to a user-specified Confluence page; project-documentation-to-confluence, which runs the core project-documentation skill and then publishes the result there; investigate-to-confluence, which runs the core investigate skill and publishes the resulting investigation report there; code-overview-to-confluence, which runs the core code-overview skill and publishes the resulting overview there; plan-a-feature-to-confluence, which runs the core plan-a-feature skill and publishes the spec and its companion artifacts there as a page tree; and work-items-to-jira, which creates one Jira ticket per slice from a work-items file. All work through the Atlassian MCP server. Depends on han-core, han-planning, and han-coding (its wrapper skills run skills from each) and requires a configured Atlassian MCP server. Opt-in: installed on its own, not pulled in by the han meta-plugin.	—	./han-atlassian
han-linear	Linear-facing extensions to the Han suite. Adds work-items-to-linear, which creates one Linear issue per slice from a work-items file. Works through the Linear MCP server. Depends on han-core and requires a configured Linear MCP server. Opt-in: installed on its own, not pulled in by the han meta-plugin.	—	./han-linear
han-plugin-builder	Guidance for building Claude Code skills, agents, and plugins. The guidance skill answers authoring questions and, run with init, vendors the full guidance set into a repo as a path-scoped rule index so the right guidance surfaces while editing skill and agent files. Opt-in and dependency-free: installed on its own, not pulled in by the han meta-plugin.	—	./han-plugin-builder

han

Install to Claude Code

README