# Fog

> Maintain a FOG.md unknowns ledger for a task. Use when a task has unresolved decisions or unverified constraints, when the user mentions unknowns or the fog ledger, or when another fog-* skill needs the ledger rules.

- **Type:** Skill
- **Install:** `agentstack add skill-leoncuhk-defog-fog`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [leoncuhk](https://agentstack.voostack.com/s/leoncuhk)
- **Installs:** 0
- **Category:** [AI & ML](https://agentstack.voostack.com/c/ai-and-ml)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [leoncuhk](https://github.com/leoncuhk)
- **Source:** https://github.com/leoncuhk/defog/tree/main/skills/fog

## Install

```sh
agentstack add skill-leoncuhk-defog-fog
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Fog

Fog is the gap between the map (prompt, plan, assumptions) and the territory (codebase, APIs, real constraints, user taste). The ledger makes fog visible and burns it down to a defined end.

## The ledger

One file per task: `FOG.md`, next to where the work happens (or where the user says). When a second task joins the directory, rename the existing ledger to `FOG-.md` before creating the new one, also slugged.

```markdown
# FOG: 

## Open
- [KU]  → lookup
- [KU]  → ask
- [UK]  → show
- [UU?]  → scout

## Assumed
- [A]  — cost to revisit: 

## Resolved
- [x]  (, ) — 

## Deviations            
- 
```

`territory` covers anything verified against the real system, including your own experiments. Each arrow names the resolver: `→ lookup` you do yourself; the rest are the matching fog-* skill.

## Quadrants and their resolvers

| Tag | Fog type | Resolver |
|---|---|---|
| — | Known known | Not fog. Straight into the spec. |
| `KU` | Known unknown, **fact** | `→ lookup` — the territory answers it. Never ask what code or docs can answer. |
| `KU` | Known unknown, **decision** | `→ ask` (`fog-ask`) |
| `UK` | Unknown known — taste, recognized only on sight | `→ show` (`fog-show`) |
| `UU?` | Suspected unknown unknown | `→ scout` (`fog-scout`) |
| `A` | Low-risk residue | Take the most reversible default and label it. |

## Rules

- **Every open item carries its resolver.** The ledger is a work queue, not a diary.
- **Burn-down is visible.** Announce ` open,  assumed` after every ledger write. Planning is complete when every open item is resolved or converted to a labeled assumption.
- **Assumptions are vetoable, not silent.** Present them as one batch; never interleave with blocking questions.
- **Resolved keeps its why** — decisions and territory findings that shaped the plan. A finding shaped the plan only if a later step would act differently knowing it; the rest is dropped.

## Lifecycle

- **Birth:** any fog-* skill that would write to a missing ledger (or section) creates it first.
- **Handoff:** the ledger plus the persisted plan (see `fog-plan`) is the launch packet — hand both to any fresh context or subagent.
- **Death:** after the task's acceptance gate (merge, sign-off, or delivery) passes, graduate the whys that are hard to reverse or surprising without context into ADRs, docs, or the commit message, then delete the ledger. It is working memory, not documentation.

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [leoncuhk](https://github.com/leoncuhk)
- **Source:** [leoncuhk/defog](https://github.com/leoncuhk/defog)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-leoncuhk-defog-fog
- Seller: https://agentstack.voostack.com/s/leoncuhk
- Browse the marketplace: https://agentstack.voostack.com/browse

---
Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.