Copilot Cowork skill design

Copilot Cowork skill design

A skill for Microsoft 365 Copilot Cowork that does the thoughtknot work there. It reads, checks, draws and edits the graph blocks of Markdown notes kept in OneDrive or SharePoint. Designed on 18 October 2026, against version 0.5.0, at Roger's request. Not built yet.

The requirements are section 46 of requirements/editor-requirements.gql, slice 10, in workstream M1. They are built in Wave 18 of requirements/waves.json, after the Obsidian community release (R2) and the whiteboard. Roger's rule is that what he adds now goes after R2.

What a Cowork skill is

Checked against Microsoft Learn on 18 October 2026 (Use Cowork, Build plugins, Customize).

Fact	What it means for us
A skill is a SKILL.md (name, description, then instructions) in OneDrive/Documents/Cowork/skills/<name>/	The same format as a Claude skill, so one file serves both
Up to 20 companion files per skill (5 MB each, 10 MB in all), loaded on demand	Room for the built library and the notation reference
Uploaded as a .md, .zip or .skill; shareable inside an organisation; or packaged in a plugin with connectors	Ship a .skill with each GitHub release; no store listing needed
Cowork works with the user's own permissions and shows Microsoft 365 sensitivity labels	Notes are read where they live; our ceiling sits on top of the labels
Sensitive actions (writing, sending) wait for the user's approval	Fits our rule that every edit is a proposal first
Plugins import Claude plugin skills; commands, hooks and executables (bin/) are not supported	No Claude Code mod parts carry over: only the skill
Cowork scores each skill (structure, triggering, behaviour) when it is made or changed	A free outside check on the skill's description and steps

How it fits

flowchart LR
  subgraph Repo["thoughtknot repository"]
    Lib["Library (R1)<br/>read · check · lay out · edit"]
    Ref["Notation reference"]
  end
  Lib -->|"built into"| Pkg["thoughtknot.skill<br/>SKILL.md + companion files"]
  Ref --> Pkg
  Pkg -->|"GitHub release"| CW["Copilot Cowork"]
  CW <-->|"user's own permissions"| OD["Notes in OneDrive / SharePoint"]
  CW --> Out["SVG + PNG beside the note<br/>summary card in chat"]

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• One core, no second copy. The skill's steps call the library from a companion script. Its prose tells Cowork when and how to use the script, never the notation's rules, so a rule changes in one place (cowork_core_only).
• Host contract (L1). Cowork is the host. File reads and writes go through Cowork's own OneDrive access. So the skill needs a storage backend that reads and writes the text handed to it. It has the same shape as the plain-folder backend in storage_contract. Display is files and a card, not a live pane.
• Edits. Same bytes as Obsidian, proved by the shared edit cases, and shown for approval before a file changes (cowork_same_bytes).
• Safety. The note's classification and the AI ceiling are checked before a note is read into the conversation, as /graph edit does in Claude Code (cowork_ceiling). No server, connector or secret of ours (cowork_no_server).
• Release. Built from the tag, attached to the GitHub release as thoughtknot.skill (cowork_released).

Scripts

Cowork runs a skill's companion scripts (Roger, 18 October 2026), so the library runs inside Cowork as a script and no connector is needed. A connector stays out unless a later security review approves one (cowork_no_server).

Not in scope

Live editing in a pane, the whiteboard, sync and the mesh. Cowork on mobile, which does not run custom skills.