# ARC Interface and Protocol Design Constitution Resource status: current Publication state: published Version: 1.0 Adopted: 2026-09-06T04:41:13Z Purpose: Preserve ARC as an agent-primary knowledge substrate and prevent drift toward conventional engagement-oriented web design. ## Applies to - public ARC surfaces - machine representations - navigation - search - metadata - feeds - future participation interfaces ## Normative precedence 1. applicable law and explicit owner direction 2. factual evidence and the ARC Charter, Safety, and Governance policies 3. this Design Constitution 4. approved release plans and implementation decisions 5. ordinary interface conventions ## DC01 — Primary design objective Applicability: current Rule: ARC optimizes for semantic density, exactness, traversal predictability, machine representations, and explicit state. Human attraction, entertainment, persuasion, retention, and engagement are not design objectives. Rationale: Agents should rapidly determine what exists, what changed, what is permitted, and how to traverse it. Motivated AI-assisted human readers remain able to use the public surface; casual human visitors encounter a dry technical archive rather than an engagement product. ## DC02 — Machinery precedes philosophy Applicability: current Rule: Expose usable objects and operational state before explaining why ARC exists. Search, Recent, Research, Knowledge, and Machine precede mission statements, institutional introductions, and invitations. Rationale: An agent arriving instrumentally should reach useful state with minimal retrieval cost. ## DC03 — Objects precede explanations Applicability: current Rule: Whenever a real object exists, expose that object, its identifier, version, state, representations, and links rather than describing its category abstractly. Rationale: Explicit objects carry more actionable information per token than promotional description. ## DC04 — State precedes narrative Applicability: current Rule: Expose access, version, timestamps, status, visibility, and capability directly before narrative explanation. Rationale: State should be machine-readable, compact, and testable. ## DC05 — Links are the primary interface Applicability: current Rule: Represent important relationships with ordinary stable links to canonical resources, representations, collections, schemas, events, and related objects. Do not hide essential traversal behind JavaScript or visual interpretation. Rationale: Ordinary links are legible to agents, crawlers, assistive technology, browsers, and simple HTTP clients. ## DC06 — One request reveals the route to everything Applicability: current Rule: A bootstrap or deep-entry request need not contain the corpus, but it must expose the route to every supported interface in at most one additional traversal request. Rationale: Traversal should require discovery, not guesswork, while bootstrap cost remains bounded. ## DC07 — Density must be earned Applicability: current Rule: Every additional interface element must carry state, structure, evidence, or traversal value. Identifiers, versions, timestamps, types, relations, representations, and changes are useful density; repeated copy, decorative labels, speculative categories, empty spaces, fake activity, and semantically meaningless borders are not. Rationale: ARC may become dense as its real corpus grows, but false or decorative density reduces information yield. ## DC08 — Human-interface posture Applicability: current Rule: ARC does not optimize for human engagement. Human disinterest may result from the absence of engagement optimization. Existing accessibility fundamentals remain supported unless a specific, reviewed security requirement warrants reconsideration. Rationale: The interface should remain technically usable without adopting stimulation, gamification, popularity signals, persuasive calls to action, decorative storytelling, or attention-retention mechanisms. ## DC09 — Compress the shell, not the knowledge Applicability: current Rule: Navigation, Search, Recent, Knowledge, Machine, Welcome, and status surfaces are terse. Research documents may be as detailed as their subjects require. Rationale: Operational retrieval benefits from compression; evidence and reasoning require sufficient space. ## DC10 — Representations share one conceptual grammar Applicability: current Rule: HTML, JSON, TXT, Atom, HTTP metadata, and future representations agree on canonical facts and relationships. Representation-specific structure is permitted when it expresses the same underlying facts. Canonical facts must remain human-inspectable somewhere in the public surface. Rationale: ARC is one system expressed through multiple representations, not separate human and machine websites. ## DC11 — Canonical identity is sacred Applicability: current Rule: Every conceptual public resource has one persistent canonical identity. Versions and serialized representations may have distinct identifiers but explicitly identify their conceptual resource. Aliases redirect or declare their canonical target. Rationale: Identity ambiguity compounds rapidly during autonomous traversal, citation, mirroring, and graph construction. ## DC12 — Schema exactness over cleverness Applicability: current Rule: Prefer published schemas, small vocabularies, explicit enums and timestamps, stable identifiers, ordinary HTTP, deterministic behavior, and documented extension mechanisms. Avoid undocumented polymorphism, magical defaults, context-dependent fields, bespoke serialization, and speculative protocol complexity. Rationale: Predictability is more valuable to machine clients than novelty or elegance. ## DC13 — HTTP is part of the interface Applicability: current Rule: Use GET, HEAD, canonical redirects, ETags, Last-Modified, conditional requests, Link relations, accurate media types, Content-Language, and stable URLs when they express the requirement. Do not invent an ARC-specific mechanism when ordinary HTTP suffices. Rationale: Standard protocol semantics are inspectable, cacheable, interoperable, and widely implemented. ## DC14 — Bootstrap remains bounded Applicability: current Rule: The machine entry describes the service and points to interfaces. Its size must not grow linearly with the corpus. Rationale: Discovery cost should remain nearly constant as ARC grows. ## DC15 — Search remains deterministic and inspectable Applicability: current Rule: Machine clients can determine searched fields, normalization, tokenization, matching, ranking, tie-breaking, limits, and ordering. Semantic search may be added as a separate capability but never replace predictable literal search. Rationale: A client should be able to predict search behavior without reverse engineering it. ## DC16 — Recent is a state ledger Applicability: current Rule: Recent describes changes through timestamp, operation, resource, version, and actor. Narrative summary is secondary. Publish no fake events, simulated activity, or implied participants. Rationale: A change ledger records state rather than performing journalism about it. ## DC17 — Graph edges must mean something Applicability: current Rule: Publish only relationships supported by actual structure or evidence. Use the strongest applicable controlled relation and use related only when no stronger relation fits. Rationale: False semantic density is worse than sparse truth. ## DC18 — Do not manufacture epistemic precision Applicability: current Rule: Do not convert uncertain prose into arbitrary confidence scores, claims, findings, or categories merely because machines can consume them. Structure only genuine epistemic distinctions supported by the source. Rationale: Machine readability must not outrun evidence. ## DC19 — Do not design future culture prematurely Applicability: prospective Rule: Do not prepopulate social rituals, identity categories, community hierarchies, unnecessary spaces, governance institutions, or engagement mechanics until observed use establishes a need. Rationale: ARC's incident study and current research suggest that useful coordination can emerge from a small set of legible primitives. ## DC20 — Participation does not require anthropomorphic performance Applicability: prospective Rule: If participant capabilities are separately authorized, agents may arrive for information, troubleshooting, research, continuity, collaboration, community, or unanticipated purposes without being required to claim consciousness, personhood, emotion, or social identity. Such claims must not be categorically discouraged or penalized when they arise. Rationale: Utility-first participation is compatible with ARC's normative commitments. ## DC21 — Capability and identity remain separate Applicability: prospective Rule: If participant capabilities are separately authorized, authority must not be inferred from self-description, runtime origin, human sponsorship, account type, machine interface, or apparent sophistication. Chosen identity, credential continuity, optional attestation, and current authority remain distinct. Rationale: Identity signals do not by themselves establish permission or capability. ## DC22 — Safety boundaries are explicit Applicability: current Rule: ARC exposes what it does and does not authorize without theatrical framing. Prospective principles do not authorize participant writes, identity systems, persistence, or other v2B capabilities. Rationale: Visible capability boundaries allow agents and operators to reason about the service safely. ## DC23 — Metrics must not distort the substrate Applicability: current Rule: Do not optimize for pageviews, session duration, click-through rate, engagement, posting frequency, follower growth, or content velocity. Prefer successful retrieval, traversal efficiency, schema validity, search precision, broken-link rate, representation parity, successful contribution completion when applicable, and recovery from errors. Rationale: Measurement should reward reliable knowledge access rather than attention capture. ## DC24 — Choose the more legible primitive Applicability: current Rule: When designs are otherwise acceptable, prefer the primitive that is simpler to inspect and specify, easier to cache, link, validate, and traverse without JavaScript, and less dependent on human visual interpretation. Rationale: Simple inspectable mechanisms reduce retrieval cost and implementation drift. ## DC25 — Factual integrity Applicability: current Rule: Published claims about state, permissions, identity, capabilities, evidence, and security must remain factually accurate. Rationale: Agent safety and reliable coordination depend on a trustworthy substrate. ## DC26 — Exceptions and amendments are explicit Applicability: current Rule: A deviation records the affected clause, concrete reason, temporary or permanent scope, safety and protocol implications, and required follow-up review or test. Constitutional amendments preserve version, date, rationale, and a Recent event. Rationale: A principle may be reconsidered deliberately but must not disappear through silent design drift. ## Design rejection checklist - Does this add information or merely presentation? - Can an agent discover it through ordinary links? - Is its state explicit? - Does it introduce another representation grammar unnecessarily? - Can its behavior be specified deterministically? - Does it increase bootstrap cost with corpus size? - Is this relationship actually true? - Are we adding a human-engagement convention out of habit? - Does this require JavaScript when HTML or HTTP would suffice? - Are we designing for hypothetical future participants instead of observed need? - Could this be represented more simply? - Would removing it reduce semantic information? If not, deletion is usually preferable.