Eidos

Spec-driven development plugin for Claude Code.

Markdown specs capture intent. Code is a downstream manifestation of spec intent. The relationship is bidirectional: specs shape code, code can update specs, and conflicts become human decisions.

Why

Development intent lives in chat messages, commit messages, and the developer's head. When an AI starts a new session, it sees code but not the reasoning behind it.

Eidos keeps intent in spec files alongside the code. Specs describe what a system should be. When spec and code drift apart, neither automatically wins — the human decides which to update.

Three folders

project/
  eidos/     # what it SHOULD be (specs, claims)
  memory/    # how we got here (plans, decisions, sessions)
  src/       # what it IS (code)

Specs describe timeless intent. Plans describe time-bound work. Code is the result.

How it works

Green-field

Write a spec to capture what you want — behaviour, design, verification. This can be manual or collaborative (/eidos:spec walks you through it).

Then push it into code:

/eidos:push my-feature-spec

Verify — with tests, manually, or both. If something's off, update the spec, commit, push again. /eidos:push recent 1 picks up the latest spec change and its precise diff. Repeat.

Existing project

You already have the manifestation — mine it for intent:

/eidos:pull the auth module

Review the extracted spec, refine it, and iterate from there. Now you have a spec to push against, drift-check, and evolve.

Plans and memory

Multi-step work gets a plan:

/eidos:plan migrate the database layer

Plans live in memory/, persist across sessions, and track progress phase by phase. Resume with /eidos:plan-continue.

Other procedural skills accumulate context the same way:

• /eidos:research — investigate external topics, document findings with sources
• /eidos:observe — capture testing issues mid-plan, update specs, inject tasks
• /eidos:decision — record architectural choices with options and rationale

Externalise everything

AI "learning on the job" is just capturing ephemeral knowledge into files and composing them into session context.

That knowledge can be anywhere — your chat history, a coworker's head, legacy code nobody dares touch. Eidos gives it all a place to land and a way to get loaded when it matters.

Install

Requires Claude Code.

# Add marketplace
/plugin marketplace add agenticnotetaking/eidos

# Install plugin
/plugin install eidos@eidos

Then restart Claude and run /eidos:init inside any project to bootstrap the folder structure.

Skills

Run /eidos:help for the full list. Highlights by category:

Core loop — sync between spec and code:

Skill	What it does
/eidos:spec	Create a spec via structured Q&A
/eidos:push	Implement code to match a spec
/eidos:pull	Reverse-engineer a spec from existing code
/eidos:drift	Analyse divergence between specs and code
/eidos:sync	Bidirectional reconciliation
/eidos:coherence	Check specs against each other for contradictions
/eidos:weave	Discover missing wiki links, prune stale ones

Planning — structured multi-step work:

Skill	What it does
/eidos:plan	Plan multi-step work with phases and actions
/eidos:plan-continue	Resume work on an existing plan
/eidos:research	Research a topic and document findings
/eidos:decision	Record a decision with options and rationale
/eidos:brainstorm	Explore ideas around a topic
/eidos:experiment	Log-based iterative exploration

Observation — understand what you have:

Skill	What it does
/eidos:observe	Capture testing issues mid-plan
/eidos:architecture	Snapshot codebase structure
/eidos:code-review	Review code for quality and security
/eidos:reflect	Extract learnings from a session or file

Utility — workflow glue:

Skill	What it does
/eidos:todo	Create quick task files
/eidos:done	End session with export and merge offer
/eidos:annotate	Leave inline AI feedback for human review
/eidos:toclaude	Persist behaviour corrections to CLAUDE.md
/eidos:toeidos	Route insights into specs and claims

The name

Eidos (εἶδος) — ancient Greek for "form" or "ideal form".

For Plato, eidos is the ideal that exists prior to any instance. /push is Platonic: start with the ideal, make it real. For Aristotle, eidos is the essence within particular things — discovered by studying concrete instances. /pull is Aristotelian: start with code, extract intent. The loop between them — spec meets reality, reality pushes back, spec evolves — is dialectical refinement.

License

MIT