SPECLAN v0.9.9 — Draw the Diagram Right Inside the Spec

A good specification is thorough, and thorough usually means dense: walls of precise text that are correct but hard to picture. The fastest way to make a requirement click is a diagram. v0.9.9 is the release where you can draw that diagram right inside the requirement it explains — and keep editing it there as the design moves.

Watch It in Two Minutes

Prefer to see it before you read? Here's the whole flow end to end — create a diagram inside a requirement, edit it in place, and see what your AI agent reads.

Excalidraw Diagrams: The Picture Is Spec Content Now

Until now, a diagram in a spec meant a screenshot pasted into a doc — stale the moment the design changed, and invisible to the AI agent reading the spec. v0.9.9 makes diagrams first-class.

Draw without leaving SPECLAN. Put your cursor in the spec, click the insert-diagram button in the editor toolbar — or add one from the spec's Artifacts section — give it a name, and the Excalidraw canvas opens. Sketch your architecture, your flow, your state machine, whatever the requirement needs.

It renders inline. Back in the spec, the diagram appears right where it belongs, under the prose it illustrates. Not a screenshot. Not an attachment in a list below. The picture you see is the file on disk.

Edit in place. Click a diagram to reopen the canvas, change it, save — and the inline render updates to match. The picture and the words evolve together, in the same window, with no re-export and no drift.

It's just files in your repo. Every diagram is an ordinary .excalidraw.png artifact in the spec's artifacts/ folder, versioned in Git like everything else. Because it's a real PNG, it renders anywhere an image does — GitHub, your docs site, a Markdown preview. Because it's also an Excalidraw file, you can reopen it any time and keep drawing. One file, both jobs, no lock-in.

Human-readable and machine-readable. On the filesystem the diagram is a plain ![lifecycle](./artifacts/lifecycle.excalidraw.png) Markdown link, sitting inside a self-describing spec hierarchy. Your team reads the picture; your AI implementation agent reads the same plain files and puts them in context with zero special handling. Your specification was always your prompt — now the pictures are in the prompt too.

Dark-mode aware. A diagram you drew on a light background is automatically adjusted to sit comfortably in a dark editor theme, so it never glares at you. (Drew it dark on purpose? Name it .dark.excalidraw.png and SPECLAN leaves it alone.)

One Setup Step: The Excalidraw Extension, Side by Side

This is the one thing to know going in. Viewing diagrams works out of the box — no extension needed. But creating and editing them is powered by a companion VS Code extension that runs alongside SPECLAN: Excalidraw by pomdtr.

The two extensions split the work cleanly: SPECLAN owns the specification and renders the diagram inline; the Excalidraw extension owns the drawing canvas. Install it once from the VS Code Marketplace (search "Excalidraw pomdtr" in the Extensions view), and SPECLAN detects it automatically — if it isn't there when you try to draw, SPECLAN prompts you with a one-click install link. Both extensions are free.

For the full walkthrough, see the Excalidraw diagrams help page or watch the tutorial video.

Also in v0.9.9

Smarter HLRD Imports

The HLRD Import Assistant — which turns a high-level requirements document into a structured SPECLAN hierarchy — gets two upgrades.

Choose where the imported specs land. Some requirements documents describe one focused capability; others sprawl across many goals and features. Before analysis begins, you now pick between Populate here — generated specs land directly at your current tree location — and Create umbrella feature — the assistant first creates a summary feature and groups everything beneath it, keeping an already-populated tree tidy. The default is chosen for you based on where you started the import, and you can override it.

Your source is preserved. Every completed import now saves a verbatim copy of the original HLRD document as an artifact on the resulting specification, so you can always trace generated entities back to the exact text that produced them — with automatic version-safe naming that never overwrites a previous import.

A Sharper AI Chat

Authoring with AI Chat gets more precise.

@-mention to link entities. Type @ in the chat input to search your Goals, Features, and Requirements, then pick one to drop a correctly formatted reference straight into your command — as a tidy chip, not a hand-typed ID. The referenced entity's full content is automatically added to the AI's context, so the model knows exactly which spec you mean.

Select text to focus the AI. Highlight a passage in the editor and it becomes the point of interest for your next instruction — a banner shows how many words you've selected — so the AI works on exactly the part you mean instead of guessing from a description.

Get the Update

If you already have SPECLAN installed from the VS Code Marketplace, v0.9.9 will update automatically. To start drawing inside your specs, add the Excalidraw extension by pomdtr — it runs side by side with SPECLAN, and both are free.

The diagram stops being an attachment and becomes spec content: drawn where it lives, edited where it lives, and kept as plain files in your own repo — readable by your team and your AI agent alike.