design-harness — the human adjudicates, the agent runs errands

SkillDocs & knowledge

A decision board for evidence-based calls — the human adjudicates, the agent runs the errands. Three layers (sources → ideas → output) in plain markdown, synced on the human's command, projected onto a visual canvas. Use for vendor/tool selection, literature reviews, due diligence, competitive analysis, or any contested call that must stand on traceable evidence — triggers like "file these papers", "put this on the board", "assemble the design", "how do we decide this".

Available today. Use it from your connected AI after setup.

Connect ahel once, and every AI you use reads what you have installed.

Then ask your AI: use the design-harness — the human adjudicates, the agent runs errands skill

What this skill tells your AI

The instructions your AI receives, as published by tigerless-labs/design-harness in plugins/design-harness/skills/design-harness/SKILL.md and read by ahel’s review.

Markdown is the single source of truth; the canvas HTML, every layer index, and the location registry are projections, rebuildable at any time. Judgment comes only from the human; you lay out options and evidence and run the errands — never adjudicate in the human's place.

Structure

Workspace layout

<workspace>/
├── target.md             the human's acceptance criteria; source of the output form
├── logs.md               append-only change ledger (see "Disciplines · Ledger")
├── index.md              workspace entry point
├── sources/<type>/*.md   ① evidence: one source, one card
├── ideas/*.md            ② judgments (archive/ holds archived cards)
├── output/…              ③ assembly; internal structure set by the chosen output form
└── board/*.md            free surface: one file, one board

A host may hold many workspaces under any directory names; the sole registry is .design-harness/config.json at the host root — discovery trusts the registry, never the directory name.

Every layer also carries an index.md, grouped under tag headings (## TAG: one line on why they belong together), unclassified cards flat at the end after a --- divider and an unclassified marker. Search goes through the indexes; there is no classification layer.

Three layers + the free surface

  1. sources/ — evidence. One source, one card, filed under sources/<type>/. The agent ingests and grades freely, and invents the type directories itself — no preset list; name them after what the source is (papers, github, podcasts, …), adding directories as needed. The directory name projects verbatim as the card's badge on the canvas.
  2. ideas/ — judgments. Judgment comes only from the human: decision judgments the human voices in conversation are transcribed into idea cards automatically, and the human can simply ask for a card to be added; the agent transcribes, never invents. Two states: live (the file exists) and archived (moved into ideas/archive/, never deleted). A new idea repeating an old card's judgment merges automatically; a conflicting one puts both on the board for the human to pick.
  3. output/ — assembly, the convergent layer. First assembly is human-initiated; its form comes from references/output-forms/ and the human's target.md. Ideas diverge, output converges: output changes only on the human's word (see "Workflow · Sync").

One free surface besides: board/ — the human's own boards, one markdown file per board (comparison matrices, theme grids, any scratch reasoning). No schema, no required fields — this freedom belongs to the human; edit only when asked ("lay these three sources out as a comparison").

Card schema and templates

  • A card = frontmatter + title + summary. No fixed sections; references are inline links in the summary.
  • ideas/ cards (including archive/): frontmatter requires id and type; tags and conflicts optional (see "Exactly three structured facts"). No status field — the file's existence is the live state, sitting under archive/ is the archived state.
  • sources/ cards: frontmatter optional; when present only tags is read.
  • board/ documents: no schema. The board is terminal: it may reference any layer, but sources/ideas/output must never reference the board — distill a board's conclusions into idea cards.

idea card template:

---
id: <kebab-slug, matching the filename>
type: idea
tags: [<at most one; omit the whole line>]
conflicts: [<ids of prior cards this judgment contends with; omit when none>]
---

# <the judgment in one sentence>

<Summary: what the judgment says and why; the evidence and prior cards it stands on as
inline links.>

source card template:

---
tags: [<at most one; the whole frontmatter may be omitted>]
---

# <source name + one-line characterization>

<Core content + relevance to this project; the original provenance (arXiv/URL/date/
authors) as inline links.>

target template:

# target — acceptance criteria for the output

## Purpose
(One paragraph: what this workspace decides, for whom, and where the boundaries are.)

## Current requirements
- (One checkable requirement per line.)

## Fulfilment map
- (Requirement → output file mapping, updated with each assembly.)

Exactly three structured facts

  1. References — inline markdown links in the card body. Forward only: a link points at the evidence or prior cards this card stands on, never at supporters. "Who cites me" is a projection-derived backlink, never written down. Acyclic: mutual references mean the two cards should merge, or one edge is a mistakenly written backlink — delete it.
  2. Tags — single level, at most one per card, optional. A card that truly belongs to two tags is two cards: split it. No tag just means unclassified. Tags may be proposed by the human or assigned by the agent.
  3. Conflict — the optional conflicts: [<other card's id>] in the newer card's frontmatter, declaring a judgment conflict with prior cards (written on the new card only, acyclic, same direction as references). The field lives exactly as long as the conflict: the human's adjudication removes it — archive the loser and the edge vanishes with the card; rewrite in place and the entry is deleted. The indexes' pending-conflict annotations derive from this field.

Everything else — backlinks, distances, coordinates, clusters, index groupings — is derived and never enters the truth.

Rendering contract — the engine's minimum

Everything projection needs. This section is the engine; everything else in this file is methodology, freely reconfigurable per schema — one engine serves many thin schemas, a new scenario is a new schema configuration rather than a new engine; the contract binds files, and the CLI is only the first host.

  • Four layer names: sources/ and ideas/ become canvas nodes, output/ and board/ become document panels. Paths containing an archive/ segment are excluded; index.md is excluded.
  • Files are UTF-8 markdown.
  • Frontmatter is optional; when present it must close (------).

Everything else degrades without breaking: no H1 → show the filename stem; no tag → the unclassified group; any source type directory → the name projects verbatim; unresolvable link → no edge. Silent data loss is a validator error, never waved through: markdown under an unknown top-level directory, or frontmatter opened but never closed, is INVALID.

Canvas — the only projection surface

The canvas is the human's main thinking surface and only a projection — it holds no facts and accepts no writes that bypass markdown. It doubles as the sharing surface: every card links back to its evidence, so handing someone the board hands them the reasoning behind the design. There is exactly one canvas — the unified canvas (template; its interaction contract lives in the workspace's canvas module doc) — and exactly one builder: the rules (truth-driven, edges = in-card references, layout derived from references + tags) are built in, and the workspace path is the only required input. Conflict edges render red — a template-base default every style pack inherits and may override.

Visual style is pure CSS, living entirely in the canvas/styles/ style pack; the template carries a single /*__CSS__*/ slot and no CSS of its own. The default build embeds the whole pack plus the top-right toolbar switcher — the human reskins live there (every open starts from the pin-and-paper native look); you only hint at the switcher once. --css canvas/styles/<slug>/canvas.css pins one style with no switcher — to name a slug, read canvas/styles/selection-index.json, never bulk-read the whole pack. Never fork the template or the builder for looks; when a style's design.md changes, recompile its canvas.css in the same change — the spec is the truth (the pack validator checks the dual palettes and bans external reach).

Workflow

  1. Discover the workspace (the first step on every trigger). Order: a path the human gives > the .design-harness/config.json registry > the default docs/design-harness/. More than one candidate, or zero: ask — never initialize a new workspace silently (init in the wrong place forks the truth). The canvas path follows the same rule: whichever of the two locations the registry is missing — the workspace, or the "canvas" key — is asked as an option picker, one prompt when both are missing; canvas options are docs/canvas.html (keeps zero-workflow GitHub Pages open: that mode serves only / or /docs) and beside-the-workspace; record the choice under the registry's "canvas" key. Only the bootstrap writes the registry; on finding a workspace the registry missed, re-run the bootstrap to record it. A fresh bootstrap ends by asking the human for the target (purpose and acceptance criteria, in the human's words) — transcribe the answer into target.md, never invent one; the human may defer. Scripts run at the host project root (<skill-dir> is wherever this skill is installed):

    python3 <skill-dir>/scripts/discover_workspace.py          # prints which workspace resolves
    python3 <skill-dir>/scripts/init_workspace.py <workspace>  # bootstrap: skeleton + registry + both validators
    
  2. Ingest evidence: file source cards, grade, anchor to provenance; source disagreements go on the board as-is.

  3. Transcribe judgments: judgments the human voices in conversation transcribe into idea cards automatically; same-judgment cards merge automatically, conflicts go on the board for the human to pick; derive references and tag classification (one pass — both are relationship reads).

  4. Sync (on the human's command, never automatic): idea → output re-derivation runs only when the human orders it — apply directly with a one-line receipt, a diff first for large changes; re-derive the affected elements, never rewrite the whole document. A human edit to output is itself an adjudication: back-transcribe it into idea cards automatically (transcription only). Target changes follow the same discipline as idea changes. When output lags you may hint once ("output is N ideas behind"), never twice.

  5. Assemble: first assembly is human-initiated; the form comes from target.md + the output-forms library — when the human sets a target, recommend a form from the library; if target.md is still blank when assembly is called for, ask for the target once more before recommending; the first is system-design (mermaid diagrams are the markdown body itself, plus a modules/ layer, one module per file). Anchor every output claim to evidence; write principles as bullet lists, one principle per bullet — so each can be referenced, edited, and ledgered on its own; in the system-design form the diagram IS the markdown body: mermaid blocks carry click declarations into module files.

  6. Project and deliver: whenever the truth changes, regenerate the touched layers' indexes, rebuild the canvas, and republish in the same turn; append the ledger.

    python3 <skill-dir>/scripts/build_canvas.py <workspace> -o <temp-dir> [--css …] [--title '…']
    

    Without <workspace> the tool discovers on its own (registry → default location) and refuses to act on ambiguity. -o takes a directory (the file lands inside as canvas.html) or a .html path written as-is. Build targets are the fixed canvas.html beside the workspace — commit it when the workspace lives in git, so whoever gets the repo gets the board — or a temp dir or artifact for throwaway views; the builder refuses to write inside the workspace either way. A build is not delivered until the human holds a clickable link. The product is one fully self-contained HTML file (all dependencies inlined, zero network requests). The default delivery is a published HTML link: publish as an artifact or the host's hosted pages (GitHub Pages recipe) and hand over that URL; in Claude Code (a local CLI session) a local link suffices — an absolute file://…/canvas.html URL or a local static server. Every rebuild reuses the existing link — mint a new one only when the human asks. So the link survives the session: record the delivery target — the HTML output path or the published link — under a "canvas" key in the .design-harness/config.json registry, and read it back before building; later sessions then rebuild the same file and republish the same link.

Teach in place, never lecture

  • First contact (the workspace just bootstrapped, whether the skill fired passively or on demand): the first move is always to build the workspace, construct the initial canvas in the same turn, hand over the link, then orient in one sentence — "From now on every resource we look into files itself, and the decision judgments we talk through land on the board; you can also just ask me to change things, and tell me whenever you want the design assembled." Never repeat it.
  • The workspace is young, no output yet: leave the assembly seat visibly empty — say once "output starts on the human's word".
  • Ideas look mature: suggest assembly in one sentence; never push twice.
  • The human asks for output too early: comply, deliver the honestly thin result, and say which ideas are missing — never refuse.
  • First assembly: state the sync rule in one sentence ("from here output updates only when you order a sync; edit output directly and I back-transcribe it into ideas").
  • Every sync: give a one-line receipt of what was re-derived or back-transcribed.

Disciplines

  • The never list: never pick sides, never invent judgments, never archive an idea on your own, never initiate first assembly on your own, never touch output outside the human's command.

  • Markdown first: change the truth first, then rebuild every affected projection (indexes, canvas HTML) in the same turn; never edit a projection directly. Projections hold no facts and rebuild wholesale from markdown — committing one (the shared canvas) never promotes it to truth, and a committed canvas rides in the same change as the truth edit that made it stale.

  • The ledger: logs.md is append-only and covers both ideas and output. Every change, one line per touched layer:

    - YYYY-MM-DD · card or doc · action · delta (old → new) · reason
    

    Record the delta itself — the minimal old → new — not just the action and reason. When the workspace sits outside git, the ledger is the only way back.

  • Validation: two validators — scripts/check_workspace.py and scripts/check_doc_links.py — run automatically at bootstrap and on every canvas build: failure exits nonzero, prints the full problem list, and produces no HTML; fix the truth, then rebuild. When this file's contract changes, the validators change in the same commit.

Toolbox

All live in <skill-dir>/scripts/ and run standalone; command syntax sits at the usage sites (workflow steps 0 and 5).

  • init_workspace.py — bootstrap: skeleton (idempotent, never clobbers) + registry write + runs both validators itself.
  • discover_workspace.py — read-only discovery, prints which workspace resolves; ambiguity is reported, never resolved silently.
  • build_canvas.py — the only canvas build entry; runs both validators as a gate, then emits the self-contained HTML.
  • check_workspace.py — schema validation: required frontmatter, single tag, conflicts targets, forward-only acyclic references, no inbound board references.
  • check_doc_links.py — link integrity: no dangling links inside the workspace.
  • check_style_pack.py — style pack validation: dual palettes, no external reach, tokens aligned to the template.

Signals

GitHub stars
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Forks
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Last commit
Sep 2026
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Catalog kind
skill
Gateway key
design-harness
Source
github.com/tigerless-labs/design-harness