# Knowledge Graph > Build and maintain the project's knowledge graph — a tiered set of nodes under docs/graph/ that lets an agent load only the few facts a task needs instead of the whole codebase. Use when adopting a project, when a fact changes, when a node grows too large, or when a task should have matched a node's triggers and didn't. Enforces one home per fact (dedup), honest per-node budgets, cite-don't-fabricate, and a mechanical linter. The library wiki (docs/graph/libraries/) is a leaf tier of this graph, not a separate system. - Skill: `llopresto87/knowledge-graph` (Agent Skill) - Install (CLI): `npx skillmds@latest add llopresto87/knowledge-graph` - Raw SKILL.md: https://api.skillmd.com/api/skills/llopresto87/knowledge-graph/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: llopresto87 (https://skillmd.com/u/llopresto87) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/llopresto87/knowledge-graph --- # knowledge-graph The graph at `docs/graph/` is how a project stays legible when it no longer fits in a context window. Each node is one subject; edges say what a task must load with it; tiers bound the depth. An agent starts at the router index and traverses (see `context-router`); this skill is the discipline of *authoring and maintaining* what it traverses. Scale is agnostic: a "subsystem" node may describe a package in a single repo or a whole repo in a multi-repo program. The graph does not privilege either shape — nodes describe subjects, and how many repos those subjects span is a property of the project, not of the method. ## Tiers | Tier | What | Loaded | |---|---|---| | 0 | The kernel (`AGENTS.md` / `CLAUDE.md`) | Always, by the host tool | | 1 | `docs/graph/index.md` — the router | Every task, first | | 2 | `docs/graph/nodes/*.md` — one subject each | By traversal from the router | | 3 | Detailed collections below `docs/graph/` | Only when a Tier-2 node names the leaf and the task needs it | A Tier-2 node never loads another node's *content* by copying it. It names the node id and lets the traversal do the work. ## The node contract Every node begins with frontmatter. The full contract — every key's semantics (`id`, `owns`, `requires`, `peers`, `composes`, `artifacts`, `libraries`, `load_when`, `est_tokens`) and the anti-patterns — lives in `docs/graph/_schema.md`, the file installed beside the graph itself; copy an existing node rather than authoring frontmatter from scratch. The key that carries the whole design: `owns` — each fact-key appears in exactly one node's list, project-wide. An `expertise` node is authored to route, never to inform. It owns exactly two facts — `.applicability` (when this stack element is in play, and what must not be done without it) and `.composition` (which sub-expertises apply under which condition) — and it carries at least one `libraries:`/`artifacts:` edge to the depth it points at. The API, the pin, and the standard stay on those leaves; the node names the leaf that serves each purpose and restates none of them. Its specialisations hang off `composes:`, and a child that `requires:` its parent must appear in that parent's list — the reciprocity the linter checks, so a child cannot be added without the menu learning about it. ## The rules ### 1. One home per fact Every fact has exactly one owning node, declared in its `owns` list. No other file restates it; other files **link**. Duplicated facts rot asymmetrically — one copy gets updated, the other silently lies, and a lying doc is worse than a missing one. When two nodes both want a fact, extract it to a shared node and have both `require` it. Two corollaries. **One name per concept**: a term maps one-to-one onto the thing it names, a near-miss synonym is a fault rather than an alias, and the graph uses the name the world already holds — a serialized, wire, or externally held identifier is a contract, never renamed to match internal vocabulary; a deliberate mismatch is recorded so nobody "fixes" it (`skill.holistic-editing` owns the rename mechanics). **Rendered views are generated, hand-edited files are shaped for their editor**: an index table or status summary is regenerated from its home (`status-register.py`), never hand-edited; the files a human does maintain — the linter's PROJECT CONFIG, the `plant:` block — stay comment-bearing, grouped, and stably ordered, with no shape chosen for machine convenience. ### 2. Version pins live in the library tier An exact version belongs on its `docs/graph/libraries/.md` page. A node body may summarize a version only if it owns the corresponding `*.versions` fact-key; otherwise it links to the page. This keeps a version from being stated in five places and updated in one. ### 3. Cite; do not fabricate Every non-obvious claim has a source. **Never invent a URL, a CVE id, a version, or a fact to fill a section.** Write "not recorded" or "not audited" instead — an honest gap is usable; a confident fabrication is a trap. This is the single most important authoring rule, because a graph exists to be trusted over model memory. Separate **observed** from **audited**. A fact described because it was seen in source is not the same as a fact that was audited or certified, and a page's prose must never let the first read as the second — "the handler validates the token" (observed in one path) does not mean "every path validates the token" (a coverage claim nobody checked). Say which you did. Where a page's scope is partial, add an explicit **observed absences / what this page is NOT** note, so a reader cannot mistake the edge of what was surveyed for a guarantee of what holds. The same split holds for **traced versus inferred**: a claim not traced to a source, command output, or dated observation carries an explicit `verify:` marker naming what to re-check; a procedure page says whether its commands were run here; unbuilt work is written in the future tense with its owning increment named, because a present-tense sentence asserts that the thing exists. ### 4. Bodies stay small A node body stays under ~150 lines. A node that wants to be longer is two nodes — split, never grow. A node that owns no fact is a link farm: delete it rather than pad it. A leaf collection stays homogeneous in kind; an artifact of another kind is filed where its kind lives. `est_tokens` stays within 2× of the real body size — the router sums these to report context cost before work starts, so a lie here corrupts every plan. ### 5. Compound, don't restart Nodes grow with the project. Add a fact when the code gains it; add a sharp edge when it bites, dated; add a `load_when` trigger when a task should have matched and didn't. Do not pre-populate theoretical facts. Write every trigger in the forms a developer actually types, and in forms of **three characters or more**: the router drops shorter tokens, so `EF` can never route — write "entity framework" and "dbcontext" instead. On a composed child the wording decides whether it is ever reached at all, because descent tests the child's own vocabulary minus its parent's: a trigger the family already carries sits on the parent, adds nothing, and descends nobody. Give a child the words only it answers to. Compounding extends to being *wrong*: when a recorded fact is later found false — after testing or a closer survey — do not silently overwrite it. Add a dated **Correction** note *alongside* the original, keeping the original (wrong) reasoning and stating the corrected finding. A future reader needs to see *why* the belief changed, not just that it did — the discarded reasoning is often what stops the next agent from re-deriving the same mistake. (This is the single-current- truth analog of the append-only supersede rule, not a contradiction of one home per fact: the current fact still has one home; the Correction records how it got there.) ### 6. One graph, several depths `libraries/`, `sources/`, `product/`, `architecture/`, `api/`, `data/`, `prompts/`, `evaluations/`, `plans/`, `runbooks/`, `specs/`, and `decisions/` are graph leaf collections, not autonomous docs trees. A leaf without an owning-node edge is orphaned knowledge. Maintained project knowledge outside `docs/graph/` is an input to corroborate and ingest, not a second source of truth. ### 7. Never inline secret material A knowledge page records where a secret lives, never the secret itself — not a live value, and not a redacted-looking copy either (a "partially masked" token still leaks its shape, length, and prefix, and the graph is committed, searchable, and long-lived). Record a **pointer**: the secret manager path, the env-var name, the vault key — the fact a reader needs is *where to look*, and that is safe to own. ### 8. Status lives in frontmatter, in one vocabulary Anything that can be open — an ADR, a spec, a risk row, a `deviation` node — carries `status` and `status_date` in frontmatter, never in prose, using the one lifecycle vocabulary and its required companions defined in `docs/graph/_schema.md` ("Lifecycle status"); a body `## Status` section is a pointer, and a body value that disagrees is a lint failure. `graph-lint.py` checks nodes; `docs/graph/status-register.py` lints the Tier-3 leaves and is the query surface (`--open --hotfix --summary`). This skill does not restate the vocabulary — the schema is its home. ## Node body shape Answer, in this order, and nothing else: **what this is** (2–3 sentences) · **what you must know** (the owned facts — terse; bullets, tables, code) · **sharp edges** (what will bite, dated) · **where the code is** (concrete paths, not descriptions of paths) · **neighbours** (why each peer exists and when to cross to it). ## The linter `docs/graph/` ships a linter (`docs/graph/templates/knowledge-graph/graph-lint.py`, copied in and parameterized on adoption). It makes the dedup rule real rather than aspirational. It enforces: 1. Frontmatter parses; required keys present; `id` matches filename and kind. 2. Every fact-key in `owns` is unique across all nodes. 3. Every id in `requires`/`peers`/`composes` resolves; `requires` and `composes` are each acyclic — their union deliberately is not. 4. Every node is reachable from the root or listed in the index. 5. Every `libraries:` id has a page in `docs/graph/libraries/`. 6. Every `artifacts:` path resolves beneath `docs/graph/`. 7. No version pin appears in a node that doesn't own a `*.versions` key. 8. `est_tokens` is within 2× of the measured body; bodies under the line ceiling. 9. Lifecycle status is a vocabulary value with its companions, a `deviation` node carries its five fields, and `index.md` carries the `plant:` block (schema rules 12–14). 10. A `composes` edge runs between two `expertise` nodes and no others; a child that `requires` its parent is listed in that parent's `composes`; an expertise node carries at least one `libraries`/`artifacts` edge; and a `-` id is composed by the id without the suffix (schema rules 15–19). Run it before committing any graph change: ```sh python3 docs/graph/graph-lint.py # lint python3 docs/graph/graph-lint.py --graph # edges: -> requires, ~> composes python3 docs/graph/graph-lint.py --plan "" # dry-run the router ``` A graph without a passing linter is a graph that has already started to lie. Wire it into the verification gates. An authoring or maintenance pass is DONE when the linter passes, every new leaf resolves through an owning node's edge, and the facts that motivated the pass each have exactly one home — not when every possible node exists. Growth is demand-driven; stop at the passing lint. ## When the graph is wrong It will be; code moves and the graph lags. When a node contradicts the code: **the code wins on facts** (fix the node in the same change); **the node wins on contracts** (a code violation of a recorded contract is a bug, not a doc update). When a task should have matched a node's `load_when` and didn't, sharpen the trigger in the same commit. ## Reference files - `docs/graph/skills/context-router.md` — how the graph is traversed. - `docs/graph/skills/library-wiki.md` — the Tier-3 library-page discipline. - `docs/graph/skills/validate-knowledge.md` — proving the graph is usable. - `docs/graph/templates/knowledge-graph/` — the schema, linter, index, and node templates.