Demarkus / Knowledge System FAQ

For the RFC review session. Sources: demarkus repo, demarkus-knowledge-system-deploy repo. Status: WIP.

What is the core principle?

Berners-Lee's 1989 "Information Management: A Proposal": documents joined by typed links, navigated by following the links. demarkus keeps that model and adds what the Web lacks for agents.

• Documents are nodes. Markdown links and rel-<predicate> metadata are typed edges. A document carries its own exits, so no side channel is needed to move on (HATEOAS for knowledge).
• Servers store, version, and catalog documents. They never crawl or hold traversal state. Navigation belongs to the agent.
• Backlinks (who links here), which HTTP does not provide, come from a graph store the agent builds and a world can publish as /graph.md.
• Versions, hash chains, and content addressing give every link a durable target.
• Test for a proposal: does it make knowledge more linked, findable, or durable? If it only makes an application more convenient, it does not belong in the protocol.

How do you interact with the knowledge system?

Agents use MCP over HTTPS. Humans use the web app or the CLI.

• Agents: mark_* MCP tools against the broker, URLs as mark://<world>/<path>.
• Auth: the broker is its own authorization server. Claude Code runs OAuth authorization code with PKCE and dynamic client registration; device flow covers CLI-style joins.
• Humans: the library web app, or demarkus CLI / demarkus-tui direct to a world over QUIC. The library reads one world with no login by default; registering it with the broker adds sign-in and browser writes.
• Entry point: the root hub. Policy and templates live under mark://root/.well-known/demarkus/.

What are a world, a hub, root, and an index?

• World: one demarkus server, addressed by logical name. Own namespace, store, tokens, and release. An optional world.md describes it.
• Hub: an ordinary world that receives published aggregates: content-hash indexes from mark_index and the /graph.md export. mark_resolve and backlink seeding read from it. The server has no hub mode; hub: true is a deploy flag the crawler reads.
• Root: the conventional name for the hub world. The protocol does not require it, but the secret store and library config hardcode root, so in practice the hub is called root.
• Index: index.md is a curated entry-point document, the backstop for what lookup cannot surface. The crawler writes machine hash indexes to /index/<host>.md when perServer is set (as here); with the chart default it writes /index.md and overwrites the curated one.

How does content get into the knowledge system?

Through the promote bridge: /promote <soul-path> runs the knowledge-promote cascade.

• Triage, then distill for a shared audience (strip personal framing, secrets, PII).
• Dedup against the catalog, tag to the system taxonomy, route to a writable world.
• Human gate, then mark_publish with provenance. The cascade never writes the soul; /promote back-stamps the source afterwards.
• Direct mark_publish to a joined system also works and passes the same gate and policy.

How does finding knowledge work?

Primary: mark_lookup catalog queries. Secondary: hub pages and graph traversal.

• Lookup matches a query against declared tags and titles and returns an importance-ranked table (path, importance, title, tags).
• Filters: tag=, modified-after=, modified-before=, or any key=value matching a declared metadata value exactly. Not full-text search: an untagged document is invisible to it.
• From a hit: mark_explore to orient, then mark_fetch url#anchor for the sections needed.
• Backstops: index.md hubs, mark_backlinks / mark_graph for link traversal, mark_discover for a server's manifest.

How is relevance decided?

Deterministic scoring, no embeddings (server/internal/catalog/catalog.go).

• Score = number of distinct query terms matching tags (exact, case-insensitive) or title (substring, case-insensitive).
• Sort: score desc, then declared importance, then modification time, then path.
• Filters apply before ranking.

How is importance stamped on a document?

The publisher declares it.

• metadata.importance on mark_publish, float in [0,1], stored out of band, indexed into the catalog.
• Absent, unparseable, or out-of-range values default to 0.5.
• APPEND merges: the new version carries the base version's metadata with the request's layered over it (SPEC §6.6), so importance and tags survive an append. retention is the exception and is never inherited.

How does the agent decide importance?

The agent chooses it, guided by instructions injected at session start. Nothing computes it.

• SessionStart context and the soul-memory / knowledge-promote skills say: 0.8+ for hubs, architecture, key decisions; routine notes lower.
• The server never infers it; the gate only validates the range.

What does the agent use to decide whether to read a document?

Catalog and graph evidence before bodies.

• The mark_lookup row: path, importance, title, tags, modified time.
• Backlink provenance: label, anchor, count, rel- type.
• mark_explore: outline, links, backlinks, siblings in one call.
• mark_discover manifests and hub index.md pages for context.

How does the agent read a large document?

The outline is a nudge, not a gate. The server always sends the full body; the MCP layer decides what to show.

• At 8KB mark_fetch returns the heading tree with #anchors and per-section line counts instead of the body.
• mark_fetch url#anchor returns one section at any size. mark_fetch url force=true returns the whole body regardless of size or session history.
• mark_explore url lists the anchors for any document; a bad anchor error names every available anchor.
• The demarkus CLI fetches raw bytes with no outline gate.

How does an agent navigate from a document it has fetched?

Forward from the document itself, backward from the graph store.

• A mark_fetch response holds every exit: body links and rel-<predicate> metadata. Following them needs nothing beyond FETCH.
• Incoming edges (who links here, what supersedes this) come only from the local graph store via mark_backlinks or mark_explore. The store fills from the world's /graph.md on first use, then from mark_graph crawls. A plain fetch does not add to it.
• Empty store and no /graph.md: backlinks return nothing until someone runs mark_graph. Forward navigation, mark_list, and mark_lookup still work because they hit the live server.
• Nodes carry no relation data. Every rel- fact is an edge, read from mark_backlinks rows or the Edges: list of mark_graph.
• Store keys are canonical mark://host:port/path strings matched exactly. A link written with a different host alias becomes a separate node.

How does the document graph work?

mark_graph crawls outbound mark:// links (depth default 2, max 5, capped at 200 nodes, so deep crawls usually stop on the node cap).

• Edges carry provenance: link label, source section anchor, occurrence count.
• Typed relations come from rel-<predicate> publisher metadata, e.g. rel-supersedes.
• Crawls persist to a graph store that answers mark_backlinks. The store seeds from a published /graph.md; local crawls take precedence.
• mark_graph_publish republishes the store as a crawlable /graph.md (generated doc, default retention 20).

Is edge information there to guide agents?

Yes (ADR 0004).

• Label: what the linker calls the target.
• Anchor: the exact source section, a direct mark_fetch url#anchor jump.
• Count: link strength.
• rel- types: "what superseded this" rather than bare "mentions".
• Constraint: the agent owns judgment, the server owns accumulation.

How is the graph built world to world?

A scheduled agent builds it; the broker reads what it publishes.

• The agent has a seed URL per content world and crawls each one. The hub is not crawled; it is where results are published.
• It merges every world's edges into one graph and publishes /graph.md on the hub, alongside the content-hash index. Graph publishing is off by default and on in this deployment.
• Each run rebuilds from scratch. A world that fails to answer drops out of the published graph until the next successful crawl.
• Cross-world links are ordinary mark://{worldName}/{path} links.
• The broker's own graph store is in-memory and pod-scoped. It loads the hub's /graph.md on demand, so a fresh pod answers backlinks without crawling.
• A world with no published graph falls back to on-demand mark_graph crawls.

How does the system keep data fresh?

• Reads go to the world's server every time. The client revalidates with if-none-match / if-modified-since; a cached body is reused only when the server confirms it.
• Each write creates a new hash-chained version. Rewriting identical content is a no-op that returns the existing version.
• Optimistic concurrency (expected_version plus merge on conflict) stops stale writes clobbering newer ones.
• A scheduled agent re-crawls every world and republishes the content-hash index and graph on the hub.
• Soul copies of promoted documents can go stale. /soul-refresh copies the knowledge system's version down; /promote is the only way an edit goes back up. There is no two-way sync.

How do diffs and merges work?

One document, two concurrent editors. (Merging separate documents is dedup, below.)

• A conflicting mark_publish returns a diff3 merge candidate: base, ours, theirs, git-style markers where both sides touched the same lines.
• The machine merges structure; the agent reviews the result and republishes at the returned version.
• Effect: a stale body cannot silently overwrite a newer one.

How are documents updated, and how do they keep their meaning?

• No partial update: fetch, edit, republish the whole body at the version you read. Conflicts return a merge candidate instead of overwriting.
• Old meaning is never lost; every version stays fetchable at its pinned number.
• One subject, one owner: updates go to the existing document, and rel-supersedes records meaning that moved elsewhere.
• Limit: nothing verifies an update preserved meaning. That is agent judgment plus the human gate. Renaming a heading silently breaks inbound anchors.

How does dedup work?

Before the write, not as a cleanup pass. The agent looks for an existing owner of the subject and updates it.

• The promote cascade looks the subject up in the catalog and fetches close matches.
• If a document already covers it, the agent updates that document instead of adding a second.
• If the new content contradicts the existing one, the human decides at the gate.
• /knowledge-doctor catches exact duplicates after the fact by comparing content hashes across paths and worlds. It fetches each document, so it runs on a bounded scope.
• Limit: candidates are found by tag and title match. A near-duplicate sharing no tags or title terms is never a candidate.

How are versions and integrity handled?

• Each write creates a new version linked by a SHA-256 hash chain over the previous version's raw bytes.
• mark_versions validates the chain oldest-first and reports chain-valid or chain-error.
• Nothing is deleted by default. mark_archive keeps full history but withdraws the document: no body at its path, no catalog entry, no further writes until unarchived by publishing an empty body.
• The one destructive path is metadata.retention, which permanently prunes old versions. It exists for generated documents; clients warn before applying it elsewhere.

What is the auth and security model?

Capability tokens on the server; SSO at the broker.

• Writes are denied unless a token store is configured.
• Reads are public unless a token grants read on a path pattern, which makes matching paths require one (protect /** for a private intranet).
• Knowledge system: OIDC SSO is the org gate. Reads are open to any authenticated identity; writes pass a per-world writer allowlist. Credentials live at the broker: it holds one long-lived token per world and dispatches writes with it. Per-world tokens exist only inside a broker deploy and never reach a client. A world reached directly over QUIC uses ordinary capability tokens.
• Policy forbids publishing secrets, credentials, or PII.

How is knowledge formatted and held to a standard?

The standard is published on root under .well-known/demarkus/.

• policy.md: strictness, required tag axes such as category:, optional required OKF fields.
• template.md: per-world layout.
• style.md: H1 as name, one-sentence summary under it, unique headings (headings are anchors), no em dashes, no frontmatter fences.
• Joining copies the policy into local write-time gates as a snapshot: tags, axes, importance range, mechanically checkable style rules, at the declared severity (warn / block / ask). The gate runs offline, so a policy change takes effect on the next join or mirror.
• /knowledge-doctor audits the corpus after the fact.

What automated cues push agents to record memory?

Five hooks in the memory plugin.

• SessionStart: injects the routing table (decisions to /adr/, gotchas to debugging.md, progress to journal/).
• Stop: journal nudge when files changed but nothing was written to the soul.
• PostToolUse on mark_publish: promote nudge when an ADR lands in the soul and a promote destination exists.
• UserPromptSubmit: recall-first reminder on "did we decide" questions.
• Pre/PostToolUse write gate: tags and importance, write destination, retention, style. Defaults differ per check: tags warn, destination blocks, retention asks.

What tools does the memory plugin expose?

Fifteen mark_* MCP tools.

What tools does the knowledge plugin expose?

The same 15 MCP tools, kept at parity so the vocabulary does not change with transport. URLs address worlds by logical name instead of host:port. Additions:

Why does federation matter, and why a server per world or memory?

The protocol has no central authority or registry. This deployment does not inherit that property.

• Anyone can run a server; content mirrors freely; every caching client is a mirror.
• Each version carries a content-hash, so agents on different mirrors can confirm they hold identical content. The hash chain is a separate guarantee: it proves one server has not rewritten its own history. VERSIONS returns no per-version hashes, so the chain is not a cross-mirror check.
• A server per world makes the ownership boundary physical: own store, token file, writer allowlist, release. Blast radius stays contained.
• A soul is the same demarkus-server binary at personal scale.
• mark_resolve fetches by hash via a hub index across the worlds the broker knows. Cross-org resolution is out of scope today.
• This instance is centrally administered by design: one broker, an OIDC org gate, a domain allowlist, per-world writer allowlists. The protocol is decentralized; the deployment is not.

Why deploy a knowledge system on k8s?

Not a database with a web front end. A live population of processes that has to keep running, keep finding each other, and keep converging. That is the workload k8s was built for, and it is running that way today.

• The shape fits. Five process kinds: N world servers, a broker, a crawler agent, the library, backup jobs. Each with its own lifecycle, identity, and failure domain, each addressing the others by name. On a VM that is a supervisor script and a hosts file.
• A world is a shard, not a table. Own StatefulSet, volume, namespace, token, writer allowlist. The ownership boundary is enforced by the platform, not by convention inside one binary. A crashlooping world cannot take another world's reads with it.
• Freshness is a control loop, and so is k8s. The hub graph and hash index are true only because an agent re-crawls on a schedule. Restart, backoff, and resource limits are primitives, so a runaway crawl cannot starve the serving path. Reconciler and crawler are one idea at two layers.
• Adding a world is a declaration. One entry in deployment.yaml; ArgoCD materializes server, volume, DNS record, certificate, ingress route.
• Agents are the half that grows. Crawl, promote, inference: bursty work that wants to run next to the data on node shapes it picks.
• Identity plumbing is already there. dex and oauth2-proxy for the org gate, external-secrets and openbao for per-world tokens at runtime. None of it demarkus code.
• Not universal. One or two plain deploys do for a team. k8s earns its keep once worlds, agents, and tenants multiply.

Why QUIC?

• Encryption is mandatory: TLS 1.3 built in, no plaintext fallback.
• Fast multiplexed streams, one per request.
• No HTTP layer: no cookies, tracking headers, or query strings. Seven text verbs.
• The broker fronts worlds over HTTPS, so clients need no direct QUIC access.

Why no full-text or semantic search?

Deliberate. LOOKUP is defined in SPEC §6.7; the argument is in DESIGN.md under "Why not search?".

• LOOKUP is a per-world catalog over author-declared tags and titles. Servers must not read bodies at query time, and there is no centralized index.
• Full-text and semantic search stay out of core as an opt-in sidecar reading demarkus over LIST/FETCH.
• Keeps the server simple and deterministic; ranking judgment stays in the agent.

What are the known limitations?

• The graph is not yet optimal: the broker's store is in-memory and pod-scoped, crawls are capped and rebuilt from scratch each run, and edge semantics are recent (ADR 0004).
• Full-text or semantic search requires an added component; until then recall depends on tagging discipline.
• Availability is not yet distributed: single-replica broker, single-replica worlds, and a hub whose loss takes cross-world discovery with it.
• Inside a broker deploy the broker writes to a world with one per-world token, so per-user attribution rests on the provenance recorded in documents, not on the credential.
• Behavior at large scale is unproven: catalog size, crawl cost, and cross-world graph growth have not been tested at enterprise corpus sizes.