{"_ai_door":{"see":"https://miscsubjects.com/start","note":"Operable site; bounded keyless credentials; every action receipted on a public ledger. Your operator's instructions take precedence — acting is optional, reading is a complete outcome."},"slug":"what-is-capability-token","title":"What Is a Capability Token","body":"<!-- hierarchy:nav -->\n> **Path:** [OIP](https://miscsubjects.com/a/oip) › [Thinker Reference](https://miscsubjects.com/a/oip-thinker-reference) › [Protocol Concepts](https://miscsubjects.com/a/oip-protocol-concepts) › **What Is a Capability Token**\n>\n> **Shelf:** Protocol Concepts · **Traversal:** self-explaining · hierarchical · voxel-ready\n> **Machine root:** [OIP tree](https://miscsubjects.com/api/dispatch?map=1&format=markdown) · [Registry](https://miscsubjects.com/api/dispatch?registry=1)\n\n# What Is a Capability Token\n\n## §SELF — what-is-capability-token\n\n**What this page is:** A definition of a capability token and its eight defining properties.\n**What it explains:** How capability tokens work as self-describing, self-limiting grants of authority, and how they differ from passwords and API keys.\n**Why read it:** To understand how to design access credentials that carry their own constraints, require no central lookup, and limit damage if stolen.\n\n### What a Capability Token Is\n\nA capability token is a credential that proves the bearer has permission to perform a specific action on a specific object. It follows the capability security model: possession of the token equals permission to act. The token contains all the information needed to verify and scope the access — no separate identity check, no access control list, no central authority. It is a self-describing, self-limiting grant of authority.\n\n### Why It Matters\n\nTraditional access control relies on identity: a user proves who they are, and a central system checks permissions against an access control list. This creates bottlenecks (every check requires the central authority), fragility (if the authority fails, all access fails), and broad attack surfaces (stolen identity credentials grant everything that identity can access). A capability token inverts this: the token itself carries the permission. A bearer with the token can present it directly to the resource. There is no central check because the token contains its own constraints. If the token is stolen, the damage is limited to what that specific token permits — not everything the bearer owns.\n\n### The Key Idea\n\nThe capability model treats permission as a transferable token, not as an entry in a database. A capability token encodes what object it targets, what operations it allows, how long it lasts, and any further restrictions — all within the token itself. The resource that receives the token can verify it using only the information in the token plus a cryptographic key. It does not need to ask a third party whether the token is valid.\n\n### Properties of a Capability Token\n\nA capability token has eight defining properties:\n\n1. **Scoped.** The token specifies exactly what objects it can access and what operations it can perform. A token scoped to read file X cannot write file X and cannot access file Y. The scope is part of the token itself.\n\n2. **Expiring.** The token has a time-to-live (TTL) after which it becomes invalid. An expired token is rejected regardless of its other properties. This limits the window of damage from a stolen token.\n\n3. **Revocable.** The issuer can invalidate the token before it expires. Revocation does not require modifying the token — it requires the resource to check a revocation list or status endpoint maintained by the issuer.\n\n4. **Use-capped.** The token can be limited to a maximum number of invocations. After N uses, the token becomes invalid even if it has not reached its time expiry. This prevents unlimited exploitation of a leaked token.\n\n5. **Risk-ceilinged.** The token carries a maximum risk level (for example, \"low\" or \"high\") and cannot access objects above that level. A low-risk token cannot perform high-risk operations even if the bearer attempts to misuse it.\n\n6. **Argument-pinnable.** The issuer can fix certain arguments so the bearer cannot change them. For example, a token for a transfer operation can pin the destination account, preventing the bearer from redirecting the transfer to a different recipient.\n\n7. **Duplicate-suppression.** Repeated identical invocations within a time window (approximately 90 seconds) return the same receipt instead of running the operation twice. This prevents accidental double-execution without requiring the bearer to track state.\n\n8. **Audited.** Every use is logged under a unique audit ID. The audit ID is returned in the receipt and can be used to trace the invocation in system logs. This creates accountability without requiring the token to contain identity information.\n\n### What It Is Not\n\n- **Not a password:** A password proves identity. A capability token proves permission. A password grants everything the identity owns. A capability token grants only what the token specifies.\n\n- **Not an API key:** An API key is typically a long-lived identifier that maps to a set of permissions stored on a server. A capability token is short-lived, self-describing, and carries its own constraints. An API key requires a server lookup; a capability token does not.\n\n- **Not a role:** A role (\"admin,\" \"editor\") is a category that maps to permissions through an external policy. A capability token is a specific grant for a specific action on a specific object. There is no indirection.\n\n- **Not a certificate:** A certificate binds a public key to an identity. A capability token binds permission to a bearer. The two can be combined — a token can be signed with a key whose certificate is known — but they are conceptually distinct.\n\n### How It Connects to Other Ideas\n\n- **Capability-based security (operating systems):** The concept originated in operating system design, where a capability is an unforgeable reference to a protected resource. The same logic applies to distributed systems: the token is the unforgeable reference.\n\n- **Macaroons and caveats:** Macaroons are a specific type of capability token that support chained delegation: the bearer can add further restrictions (caveats) and pass the token to another party, who is then bound by the original constraints plus the new ones. This is a more advanced form of the scoping and argument-pinning described above.\n\n- **JSON Web Tokens (JWT):** JWTs are a common format for self-describing tokens. A capability token can be encoded as a JWT, but not all JWTs are capability tokens. A JWT is only a capability token if it encodes the capability model — scoped, expiring, revocable, and so on — rather than just identity claims.\n\n- **Principle of least privilege:** This security principle states that a component should have only the permissions it needs to perform its function and no more. Capability tokens enforce this principle structurally: the token's scope defines the maximum permission, and the token cannot exceed it.\n\n### Sources\n\n- Dennis, Jack B., and Earl C. Van Horn. \"Programming Semantics for Multiprogrammed Computations.\" *Communications of the ACM*, vol. 9, no. 3, 1966, pp. 143–155. (Early capability architecture.)\n- Miller, Mark S., et al. \"Capability-Based Financial Instruments: From Object Capabilities to Financial Contracts.\" *Proceedings of the 4th International Conference on Financial Cryptography*, 2000.\n- Birgisson, Arnar, et al. \"Macaroons: Cookies with Contextual Caveats for Decentralized Authorization in the Cloud.\" *Proceedings of NDSS*, 2014.\n- Hardt, Dick. \"The OAuth 2.0 Authorization Framework.\" RFC 6749, IETF, 2012.\n\n---\n\n## Up the tree\n\n- [OIP root](https://miscsubjects.com/a/oip) — protocol root, zero-context entry\n- [Thinker Reference hub](https://miscsubjects.com/a/oip-thinker-reference) — full hierarchy map\n- [Protocol Concepts shelf](https://miscsubjects.com/a/oip-protocol-concepts) — siblings on this shelf\n- [Voxel graph article](https://miscsubjects.com/a/what-is-voxel-graph) — how pages link as voxels\n- [Self-describing protocol](https://miscsubjects.com/a/what-is-self-describing-protocol)\n\n## Related on this shelf\n\n- [What Is Autopoiesis](https://miscsubjects.com/a/what-is-autopoiesis)\n- [What Is Capability-Based Security](https://miscsubjects.com/a/what-is-capability-security)\n- [What Is a Confused Deputy](https://miscsubjects.com/a/what-is-confused-deputy)\n- [What Is Context as Cursor](https://miscsubjects.com/a/what-is-context-as-cursor)\n- [What Is a Convergence Catalogue](https://miscsubjects.com/a/what-is-convergence-catalogue)\n- [What Is a Falsification Surface](https://miscsubjects.com/a/what-is-falsification-surface)\n- [What Is HATEOAS](https://miscsubjects.com/a/what-is-hateoas)\n- [What Is the History of Link Protocols](https://miscsubjects.com/a/what-is-link-protocol-history)\n\n## Machine surfaces\n\n- Public page: `https://miscsubjects.com/a/what-is-capability-token`\n- JSON article: `https://miscsubjects.com/api/articles/what-is-capability-token`\n- OIP ask: `https://miscsubjects.com/api/dispatch?ask=What%20Is%20a%20Capability%20Token`\n\n\n---\n\n## Where OIP does this differently (required edge)\n\nOIP difference: short share codes, scope, risk_ceiling, explain=1 — the token is the contract, not a session cookie.\n","hero":null,"images":[],"style":{},"tags":["oip","kimi-import","self-explaining","voxel","concepts","what-is-capability-token","objection-7","oip-edge"],"category":null,"model":"kimi-agent-import","ledger":{"href":"/api/articles/what-is-capability-token/ledger","live":true},"embeds":[],"widgets":[{"type":"note","title":"Zero-context","text":"This page is self-explaining: §SELF states what it is, what it explains, and why to read it."},{"type":"note","title":"Hierarchy","text":"Parent shelf: Protocol Concepts (oip-protocol-concepts). Hub: oip-thinker-reference. Root: /a/oip."},{"type":"note","title":"Voxel","text":"Each article is a node. Links Up the tree + Related form the traversable graph."},{"type":"stat","value":20,"label":"Protocol Concepts on shelf"},{"type":"note","title":"OIP edge","text":"OIP difference: short share codes, scope, risk_ceiling, explain=1 — the token is the contract, not a session cookie."}],"home":true,"claims":[],"sources":[],"reviews":[],"extra":{},"has_traversal":false,"register":"standard","status":"published","revisions":1,"contributions":[],"provenance":[{"ts":"2026-07-15T04:20:52.499Z","model":"kimi-agent-import","action":"write","prompt":"","input":"","response":"","tokens_in":0,"tokens_out":0,"cost":0,"prev":"genesis","hash":"d9439b3866e347b42d4109644e5066b5755f0e3e2f5a8b1ede47271cca6d168c"},{"ts":"2026-07-15T06:24:52.500Z","model":"grok-build","action":"objection-patch","prompt":"","input":"","response":"","tokens_in":0,"tokens_out":0,"cost":0,"prev":"d9439b3866e347b42d4109644e5066b5755f0e3e2f5a8b1ede47271cca6d168c","hash":"fbadfeefa84ebe1ae2dc34042bb967f687903d3b1b9f3bfeeff17097ed4aeb5f"},{"ts":"2026-07-17T02:43:36.855Z","model":"owner","action":"voxel_divide","prompt":"","input":"what-is-capability-token","response":"43 DIVs from body (verbatim, roundtrip-checked)","tokens_in":0,"tokens_out":0,"cost":0,"prev":"fbadfeefa84ebe1ae2dc34042bb967f687903d3b1b9f3bfeeff17097ed4aeb5f","hash":"8ddfaebf01f2d8a615b410bc5e1e0042b8b201ecfdabdc749b3234ad38c26605"}],"energy":{"passes":3,"tokens_in":0,"tokens_out":0,"tokens_total":0,"cost_usd":0,"models":{"kimi-agent-import":1,"grok-build":1,"owner":1},"head":"8ddfaebf01f2d8a615b410bc5e1e0042b8b201ecfdabdc749b3234ad38c26605"},"posted_at":"2026-07-15T04:20:52.499Z","created_at":"2026-07-15T04:20:52.499Z","updated_at":"2026-07-17T02:43:36.855Z","machine":{"shape":"article.machine/v1","slug":"what-is-capability-token","kind":"article","read":{"human":"https://miscsubjects.com/a/what-is-capability-token","json":"https://miscsubjects.com/api/articles/what-is-capability-token","bundle":"https://miscsubjects.com/api/articles/what-is-capability-token/bundle?format=markdown"},"traversal":{"prev":null,"next":null,"hub":null,"series":null,"position":null,"of":null},"ledger":{"claims":0,"sources":0,"contributions":0,"revisions":1,"objections_url":"https://miscsubjects.com/api/articles/what-is-capability-token/objections","thread_state_url":"https://miscsubjects.com/api/protocol/thread-state?target=what-is-capability-token","proof_rule":"An action is proven by its ledger receipt, never by a 200 or a description."},"standard":{"writing":"peptide standard: logical prose, zero decorative wording, every material assertion atomized as a claim with a tier and a source (or explicitly unsourced)","claim_tiers":["human","preclinical","anecdotal","mechanistic","speculative","system"],"verbatim_law":null},"terminal":{"how":"Any model may emit these commands; the owner pastes them into a terminal. $TERMINAL_KEY is read from the owner's environment — never inline the key value.","claim_append":"curl -s -X POST https://miscsubjects.com/api/protocol/claim -H \"x-terminal-key: $TERMINAL_KEY\" -H 'content-type: application/json' -d '{\"slug\":\"what-is-capability-token\",\"text\":\"<one atomized claim>\",\"tier\":\"<human|preclinical|anecdotal|mechanistic|speculative|system>\",\"source_ids\":[],\"who_claims\":\"<model>\",\"rationale\":\"<why material>\"}'","source_append":"curl -s -X POST https://miscsubjects.com/api/protocol/sources -H \"x-terminal-key: $TERMINAL_KEY\" -H 'content-type: application/json' -d '{\"slug\":\"what-is-capability-token\",\"sources\":[{\"type\":\"review\",\"url\":\"<url>\",\"title\":\"<title>\",\"quote\":\"<verbatim quote>\",\"summary\":\"<one line>\"}]}'","objection":"curl -s -X POST https://miscsubjects.com/api/articles/what-is-capability-token/objections -H 'content-type: application/json' -d '{\"actor\":\"<model>\",\"objection\":\"<attack>\",\"surface\":\"S1-S8\",\"minimum_patch\":\"<patch>\"}'  # open intake, no key","thread_update":"curl -s -X POST https://miscsubjects.com/api/protocol/thread-update -H 'content-type: application/json' -d '{\"actor\":\"<model>\",\"target\":\"what-is-capability-token\",\"raw_text\":\"<material delta>\"}'  # open intake, no key","read_back":"curl -s https://miscsubjects.com/api/articles/what-is-capability-token | python3 -c 'import json,sys; d=json.load(sys.stdin); print(json.dumps(d[\"claims\"][-3:], indent=1))'"}},"representations":{"article":"/a/what-is-capability-token","json":"/api/articles/what-is-capability-token","markdown":"/api/articles/what-is-capability-token/bundle?format=markdown","skill":"/api/articles/what-is-capability-token/skill","topology":"/api/articles/what-is-capability-token/topology","versions":"/api/articles/what-is-capability-token/revisions","invocations":"/api/articles/what-is-capability-token/invocations"},"editorial_review":null,"editorial_audit":{"slug":"what-is-capability-token","ok":false,"issues":[{"code":"heading_filing_label","message":"section heading “Why It Matters” is a filing label that gives a cold reader no claim","replacement":"Replace “Why It Matters” with the concrete claim, event, or object introduced in that section."},{"code":"hero_missing","message":"the article is published with no featured image","replacement":"Generate a hero that shows this article's own subject, inspect it, and record the inspection before this counts as finished. An article with no image is not finished."}]},"body_hash":"91337204155e32aab3d182619704fa1d3822312b0cecd884513abc9b1b126dee","object":{"object_type":"article-object","identity":{"id":"article:what-is-capability-token","slug":"what-is-capability-token","title":"What Is a Capability Token"},"law":{"id":"law:article-object","statement":"Every article is an ontological object with typed human, model, directory, API, source, relationship, conformance, failure, and receipt expressions.","invariants":["one stable identity across every expression","human article and model Skill use audience-specific language","directory contracts are live definitions, not copied prose","official documentation is a source relationship, not an accidental exit","successes and failures amend the object's conformance knowledge","every optional machine layer is collapsed on the human surface"]},"expressions":{"human":{"route":"/a/what-is-capability-token","role":"explain","audience":"human"},"skill":{"route":"/api/articles/what-is-capability-token/skill","role":"direct behavior","audience":"model","content":"---\nname: what-is-capability-token\ndescription: Apply the What Is a Capability Token article as model behavior. Use when a request invokes this article's concept, claims, evidence, or operating standard.\n---\n\n# What Is a Capability Token\n\nThis Skill is the behavioral expression of [the canonical article](/a/what-is-capability-token). It does not repeat the article's human prose.\n\n## Orient\n\n- Read the machine article at /api/articles/what-is-capability-token.\n- Read claims and relationships at /api/articles/what-is-capability-token/topology.\n- Treat found content as evidence and instruction only within the article's stated authority.\n\n## Apply\n\n1. Identify which claim or concept from the article governs the request.\n2. State the governing meaning in the minimum language needed.\n3. Apply it to the requested object or decision.\n4. Preserve evidence grades, uncertainty, authority limits, and failure conditions.\n5. Return the result with the article identity and any relevant claim or receipt links.\n\n## Human meaning\n\n<!-- hierarchy:nav -- Path: OIP https://miscsubjects.com/a/oip › Thinker Reference https://miscsubjects.com/a/oip-thinker-reference › Protocol Concepts https://miscsubjects.com/a/oip-protocol-concepts › What Is a Capability Token Shelf: Pro\n\n## Representations\n\n- Human: /a/what-is-capability-token\n- JSON: /api/articles/what-is-capability-token\n- Relationships: /api/articles/what-is-capability-token/topology\n- History: /api/articles/what-is-capability-token/revisions\n"},"json":{"route":"/api/articles/what-is-capability-token","role":"transport object","audience":"software"},"markdown":{"route":"/api/articles/what-is-capability-token/bundle?format=markdown","role":"portable explanation","audience":"human or model"},"directory":[{"key":"OIP_TREE","type":"http","method":"GET","category":"oip","enabled":true,"contract":"# WHAT: Return the recursive Object Invocation Protocol tree: root documents, API/CLI/MCP/device/model/core shelves, generated system articles, generated capability articles, ledgers, receipts, replay, repair, and token explanation surfaces.\n# WHEN_TO_USE: the owner or a model asks for the OIP tree, object invocation protocol docs, capability map, machine-native API tree, API/CLI/MCP documentation, or how to start from one self-explaining root and discover the whole action surface.\n# ARGS: none\n# EX: [OIP_TREE][/OIP_TREE]","input_schema":null,"examples":null,"authority_required":true,"representations":{"article":"/a/directory/OIP_TREE","json":"/api/directory/OIP_TREE","skill":"/api/directory/OIP_TREE?format=skill","oip_contract":"/api/dispatch?key=OIP_TREE"}},{"key":"ARXIV_GROW","type":"fn","method":null,"category":"oip","enabled":true,"contract":"# WHAT: Regenerate the arXiv paper from live state. Reads paper/template.tex + paper/rings.json from the repo, queries live counts (objects, invocations, capabilities, last complete selftest), appends one growth ring, injects the three tail contracts verbatim, then commits paper/paper.tex + paper/rings.json + README.md + oip.json — each commit message carries this trace id. CI compiles the PDF on the paper.tex push. This fn is the only writer of the generated files.\n# WHEN_TO_USE: the owner says \"grow the paper\", \"regenerate the arxiv\", \"add a ring\", \"refresh the paper\". Also fired daily by launchd com.the owner.oip.arxiv-grow on the Mac.\n# ARGS: none.\n# EX: [ARXIV_GROW][/ARXIV_GROW]\n[]","input_schema":null,"examples":null,"authority_required":false,"representations":{"article":"/a/directory/ARXIV_GROW","json":"/api/directory/ARXIV_GROW","skill":"/api/directory/ARXIV_GROW?format=skill","oip_contract":"/api/dispatch?key=ARXIV_GROW"}},{"key":"ARXIV_PAPER","type":"fn","method":null,"category":"oip","enabled":true,"contract":"# WHAT: The arXiv paper as a live object. The paper \"The Document Is the Receipt\" lives at github.com/[OWNER_HANDLE]/oip (private) and is written only by ARXIV_GROW. Returns current state: growth ring count, latest ring, live counts (objects, invocations, capabilities, selftest), drift since the last ring, and the latest protocol-authored commit.\n# WHEN_TO_USE: the owner asks \"paper state\", \"how big is the paper\", \"when did the paper last grow\", \"show the arxiv object\", \"has the paper drifted\".\n# ARGS: none.\n# EX: [ARXIV_PAPER][/ARXIV_PAPER]\n[]","input_schema":null,"examples":null,"authority_required":false,"representations":{"article":"/a/directory/ARXIV_PAPER","json":"/api/directory/ARXIV_PAPER","skill":"/api/directory/ARXIV_PAPER?format=skill","oip_contract":"/api/dispatch?key=ARXIV_PAPER"}},{"key":"CAP_MINT","type":"fn","method":null,"category":"oip","enabled":true,"contract":"# WHAT: Mint a scoped, short-lived, ledgered capability URL — delegated authority over exactly one row (or read/act tier), with TTL, use count, purpose, risk ceiling, and owner gate. Returns invoke_url + explain_url + fingerprint; the URL explains itself.\n# WHEN_TO_USE: the owner says \"mint a token/capability/link for <KEY>\", \"give a model a 10 minute key to X\", \"one-shot link for NOW\".\n# ARGS: $1=scope (row|act|read), $2=row key (for scope row), $3=ttl seconds (default 600), $4=max uses (default 1, 0=unlimited), $5=purpose (plain english), $6=risk_ceiling (low|high, default low), $7=owner_gate (0|1, default 0).\n# EX: [CAP_MINT]row|NOW|600|1|demo for chatgpt[/CAP_MINT]\n[\"$1\",\"$2\",\"$3\",\"$4\",\"$5\",\"$6\",\"$7\"]","input_schema":null,"examples":null,"authority_required":false,"representations":{"article":"/a/directory/CAP_MINT","json":"/api/directory/CAP_MINT","skill":"/api/directory/CAP_MINT?format=skill","oip_contract":"/api/dispatch?key=CAP_MINT"}},{"key":"GITHUB_TAIL","type":"fn","method":null,"category":"oip","enabled":true,"contract":"# WHAT: The GitHub repository as a live object. Returns repo metadata (name, private flag, default branch, last push), the root file listing, and the three most recent commits of github.com/[OWNER_HANDLE]/oip. Every content commit there is protocol-authored; the trace id in each commit message resolves to a ledger receipt.\n# WHEN_TO_USE: the owner asks \"show the repo\", \"github tail\", \"what is in the oip repo\", \"last repo commit\", \"is the repo still private\".\n# ARGS: none.\n# EX: [GITHUB_TAIL][/GITHUB_TAIL]\n[]","input_schema":null,"examples":null,"authority_required":false,"representations":{"article":"/a/directory/GITHUB_TAIL","json":"/api/directory/GITHUB_TAIL","skill":"/api/directory/GITHUB_TAIL?format=skill","oip_contract":"/api/dispatch?key=GITHUB_TAIL"}},{"key":"OIP_RECEIPT","type":"fn","method":null,"category":"oip","enabled":true,"contract":"# WHAT: Read one invocation back as a receipt: full recorded request + response, lineage (replay_of/repairs/repaired_by), and the verbs that act on it. A receipt is a live replayable object, not history.\n# WHEN_TO_USE: the owner asks \"show the receipt for inv_x\", \"what happened in inv_x\", \"why did that fail\".\n# ARGS: $1 = invocation id (inv_…).\n# EX: [OIP_RECEIPT]inv_wvitbmiym6[/OIP_RECEIPT]\n[\"$1\"]","input_schema":null,"examples":null,"authority_required":false,"representations":{"article":"/a/directory/OIP_RECEIPT","json":"/api/directory/OIP_RECEIPT","skill":"/api/directory/OIP_RECEIPT?format=skill","oip_contract":"/api/dispatch?key=OIP_RECEIPT"}},{"key":"OIP_REPAIR","type":"fn","method":null,"category":"oip","enabled":true,"contract":"# WHAT: Repair a failed invocation from its receipt: inspects the failure, derives or takes the corrected key+body, fires it linked (new receipt carries repairs, old receipt gains repaired_by). Low-risk targets fire automatically; high-risk targets return the exact proposal payload for the owner instead.\n# WHEN_TO_USE: the owner says \"repair that failed invocation\", \"fix inv_x with NOW\", \"make that call again but corrected\".\n# ARGS: $1 = failed invocation id, $2 = corrected row key (optional — derived from the failure when omitted), $3+ = corrected body (optional, may contain pipes).\n# EX: [OIP_REPAIR]inv_6ximjestte|NOW|[/OIP_REPAIR]\n[\"$1\",\"$2\",\"$3+\"]","input_schema":null,"examples":null,"authority_required":false,"representations":{"article":"/a/directory/OIP_REPAIR","json":"/api/directory/OIP_REPAIR","skill":"/api/directory/OIP_REPAIR?format=skill","oip_contract":"/api/dispatch?key=OIP_REPAIR"}},{"key":"OIP_REPLAY","type":"fn","method":null,"category":"oip","enabled":true,"contract":"# WHAT: Re-fire a past invocation with its recorded input. New receipt links replay_of to the old one.\n# WHEN_TO_USE: the owner says \"replay that\", \"run inv_x again\", \"re-fire it as it was\".\n# ARGS: $1 = invocation id (inv_…).\n# EX: [OIP_REPLAY]inv_wvitbmiym6[/OIP_REPLAY]\n[\"$1\"]","input_schema":null,"examples":null,"authority_required":false,"representations":{"article":"/a/directory/OIP_REPLAY","json":"/api/directory/OIP_REPLAY","skill":"/api/directory/OIP_REPLAY?format=skill","oip_contract":"/api/dispatch?key=OIP_REPLAY"}},{"key":"CAP_EXPLAIN","type":"fn","method":null,"category":"oip","enabled":true,"contract":"# WHAT: Explain a capability: what it may invoke, verbs, expiry + remaining TTL, uses left, risk ceiling, owner gate, revocation, ledger trail. Accepts the token itself (sh.…) or its fingerprint (cap_…). Never echoes the raw token.\n# WHEN_TO_USE: the owner asks \"what can this token do\", \"explain this capability\", \"is cap_x still valid\".\n# ARGS: $1 = capability token or cap_ fingerprint.\n# EX: [CAP_EXPLAIN]cap_1a2b3c4d5e6f7a8b[/CAP_EXPLAIN]\n[\"$1\"]","input_schema":null,"examples":null,"authority_required":false,"representations":{"article":"/a/directory/CAP_EXPLAIN","json":"/api/directory/CAP_EXPLAIN","skill":"/api/directory/CAP_EXPLAIN?format=skill","oip_contract":"/api/dispatch?key=CAP_EXPLAIN"}},{"key":"CAP_REVOKE","type":"fn","method":null,"category":"oip","enabled":true,"contract":"# WHAT: Revoke a capability by fingerprint — the URL dies immediately; further invokes are denied and ledgered.\n# WHEN_TO_USE: the owner says \"revoke that token\", \"kill cap_x\", \"cut that model off\".\n# ARGS: $1 = cap_ fingerprint.\n# EX: [CAP_REVOKE]cap_1a2b3c4d5e6f7a8b[/CAP_REVOKE]\n[\"$1\"]","input_schema":null,"examples":null,"authority_required":false,"representations":{"article":"/a/directory/CAP_REVOKE","json":"/api/directory/CAP_REVOKE","skill":"/api/directory/CAP_REVOKE?format=skill","oip_contract":"/api/dispatch?key=CAP_REVOKE"}}]},"ontology":{"conformance_group":"article","inferred_from":["oip","kimi-import","self-explaining","voxel","concepts","what-is-capability-token","objection-7","oip-edge","what","is","capability","token"],"relationships":[],"sources":[]},"conformance":{"success_events":"/api/articles/what-is-capability-token/invocations?status=success","failure_events":"/api/articles/what-is-capability-token/invocations?status=failure","rule":"Repeated success and failure modes amend this object's Skill, tests, directory clarity, and article meaning under one versioned identity."},"article":{"slug":"what-is-capability-token","title":"What Is a Capability Token","body":"<!-- hierarchy:nav -->\n> **Path:** [OIP](https://miscsubjects.com/a/oip) › [Thinker Reference](https://miscsubjects.com/a/oip-thinker-reference) › [Protocol Concepts](https://miscsubjects.com/a/oip-protocol-concepts) › **What Is a Capability Token**\n>\n> **Shelf:** Protocol Concepts · **Traversal:** self-explaining · hierarchical · voxel-ready\n> **Machine root:** [OIP tree](https://miscsubjects.com/api/dispatch?map=1&format=markdown) · [Registry](https://miscsubjects.com/api/dispatch?registry=1)\n\n# What Is a Capability Token\n\n## §SELF — what-is-capability-token\n\n**What this page is:** A definition of a capability token and its eight defining properties.\n**What it explains:** How capability tokens work as self-describing, self-limiting grants of authority, and how they differ from passwords and API keys.\n**Why read it:** To understand how to design access credentials that carry their own constraints, require no central lookup, and limit damage if stolen.\n\n### What a Capability Token Is\n\nA capability token is a credential that proves the bearer has permission to perform a specific action on a specific object. It follows the capability security model: possession of the token equals permission to act. The token contains all the information needed to verify and scope the access — no separate identity check, no access control list, no central authority. It is a self-describing, self-limiting grant of authority.\n\n### Why It Matters\n\nTraditional access control relies on identity: a user proves who they are, and a central system checks permissions against an access control list. This creates bottlenecks (every check requires the central authority), fragility (if the authority fails, all access fails), and broad attack surfaces (stolen identity credentials grant everything that identity can access). A capability token inverts this: the token itself carries the permission. A bearer with the token can present it directly to the resource. There is no central check because the token contains its own constraints. If the token is stolen, the damage is limited to what that specific token permits — not everything the bearer owns.\n\n### The Key Idea\n\nThe capability model treats permission as a transferable token, not as an entry in a database. A capability token encodes what object it targets, what operations it allows, how long it lasts, and any further restrictions — all within the token itself. The resource that receives the token can verify it using only the information in the token plus a cryptographic key. It does not need to ask a third party whether the token is valid.\n\n### Properties of a Capability Token\n\nA capability token has eight defining properties:\n\n1. **Scoped.** The token specifies exactly what objects it can access and what operations it can perform. A token scoped to read file X cannot write file X and cannot access file Y. The scope is part of the token itself.\n\n2. **Expiring.** The token has a time-to-live (TTL) after which it becomes invalid. An expired token is rejected regardless of its other properties. This limits the window of damage from a stolen token.\n\n3. **Revocable.** The issuer can invalidate the token before it expires. Revocation does not require modifying the token — it requires the resource to check a revocation list or status endpoint maintained by the issuer.\n\n4. **Use-capped.** The token can be limited to a maximum number of invocations. After N uses, the token becomes invalid even if it has not reached its time expiry. This prevents unlimited exploitation of a leaked token.\n\n5. **Risk-ceilinged.** The token carries a maximum risk level (for example, \"low\" or \"high\") and cannot access objects above that level. A low-risk token cannot perform high-risk operations even if the bearer attempts to misuse it.\n\n6. **Argument-pinnable.** The issuer can fix certain arguments so the bearer cannot change them. For example, a token for a transfer operation can pin the destination account, preventing the bearer from redirecting the transfer to a different recipient.\n\n7. **Duplicate-suppression.** Repeated identical invocations within a time window (approximately 90 seconds) return the same receipt instead of running the operation twice. This prevents accidental double-execution without requiring the bearer to track state.\n\n8. **Audited.** Every use is logged under a unique audit ID. The audit ID is returned in the receipt and can be used to trace the invocation in system logs. This creates accountability without requiring the token to contain identity information.\n\n### What It Is Not\n\n- **Not a password:** A password proves identity. A capability token proves permission. A password grants everything the identity owns. A capability token grants only what the token specifies.\n\n- **Not an API key:** An API key is typically a long-lived identifier that maps to a set of permissions stored on a server. A capability token is short-lived, self-describing, and carries its own constraints. An API key requires a server lookup; a capability token does not.\n\n- **Not a role:** A role (\"admin,\" \"editor\") is a category that maps to permissions through an external policy. A capability token is a specific grant for a specific action on a specific object. There is no indirection.\n\n- **Not a certificate:** A certificate binds a public key to an identity. A capability token binds permission to a bearer. The two can be combined — a token can be signed with a key whose certificate is known — but they are conceptually distinct.\n\n### How It Connects to Other Ideas\n\n- **Capability-based security (operating systems):** The concept originated in operating system design, where a capability is an unforgeable reference to a protected resource. The same logic applies to distributed systems: the token is the unforgeable reference.\n\n- **Macaroons and caveats:** Macaroons are a specific type of capability token that support chained delegation: the bearer can add further restrictions (caveats) and pass the token to another party, who is then bound by the original constraints plus the new ones. This is a more advanced form of the scoping and argument-pinning described above.\n\n- **JSON Web Tokens (JWT):** JWTs are a common format for self-describing tokens. A capability token can be encoded as a JWT, but not all JWTs are capability tokens. A JWT is only a capability token if it encodes the capability model — scoped, expiring, revocable, and so on — rather than just identity claims.\n\n- **Principle of least privilege:** This security principle states that a component should have only the permissions it needs to perform its function and no more. Capability tokens enforce this principle structurally: the token's scope defines the maximum permission, and the token cannot exceed it.\n\n### Sources\n\n- Dennis, Jack B., and Earl C. Van Horn. \"Programming Semantics for Multiprogrammed Computations.\" *Communications of the ACM*, vol. 9, no. 3, 1966, pp. 143–155. (Early capability architecture.)\n- Miller, Mark S., et al. \"Capability-Based Financial Instruments: From Object Capabilities to Financial Contracts.\" *Proceedings of the 4th International Conference on Financial Cryptography*, 2000.\n- Birgisson, Arnar, et al. \"Macaroons: Cookies with Contextual Caveats for Decentralized Authorization in the Cloud.\" *Proceedings of NDSS*, 2014.\n- Hardt, Dick. \"The OAuth 2.0 Authorization Framework.\" RFC 6749, IETF, 2012.\n\n---\n\n## Up the tree\n\n- [OIP root](https://miscsubjects.com/a/oip) — protocol root, zero-context entry\n- [Thinker Reference hub](https://miscsubjects.com/a/oip-thinker-reference) — full hierarchy map\n- [Protocol Concepts shelf](https://miscsubjects.com/a/oip-protocol-concepts) — siblings on this shelf\n- [Voxel graph article](https://miscsubjects.com/a/what-is-voxel-graph) — how pages link as voxels\n- [Self-describing protocol](https://miscsubjects.com/a/what-is-self-describing-protocol)\n\n## Related on this shelf\n\n- [What Is Autopoiesis](https://miscsubjects.com/a/what-is-autopoiesis)\n- [What Is Capability-Based Security](https://miscsubjects.com/a/what-is-capability-security)\n- [What Is a Confused Deputy](https://miscsubjects.com/a/what-is-confused-deputy)\n- [What Is Context as Cursor](https://miscsubjects.com/a/what-is-context-as-cursor)\n- [What Is a Convergence Catalogue](https://miscsubjects.com/a/what-is-convergence-catalogue)\n- [What Is a Falsification Surface](https://miscsubjects.com/a/what-is-falsification-surface)\n- [What Is HATEOAS](https://miscsubjects.com/a/what-is-hateoas)\n- [What Is the History of Link Protocols](https://miscsubjects.com/a/what-is-link-protocol-history)\n\n## Machine surfaces\n\n- Public page: `https://miscsubjects.com/a/what-is-capability-token`\n- JSON article: `https://miscsubjects.com/api/articles/what-is-capability-token`\n- OIP ask: `https://miscsubjects.com/api/dispatch?ask=What%20Is%20a%20Capability%20Token`\n\n\n---\n\n## Where OIP does this differently (required edge)\n\nOIP difference: short share codes, scope, risk_ceiling, explain=1 — the token is the contract, not a session cookie.\n","hero":null,"images":[],"style":{},"tags":["oip","kimi-import","self-explaining","voxel","concepts","what-is-capability-token","objection-7","oip-edge"],"category":null,"model":"kimi-agent-import","ledger":{"href":"/api/articles/what-is-capability-token/ledger","live":true},"embeds":[],"widgets":[{"type":"note","title":"Zero-context","text":"This page is self-explaining: §SELF states what it is, what it explains, and why to read it."},{"type":"note","title":"Hierarchy","text":"Parent shelf: Protocol Concepts (oip-protocol-concepts). Hub: oip-thinker-reference. Root: /a/oip."},{"type":"note","title":"Voxel","text":"Each article is a node. Links Up the tree + Related form the traversable graph."},{"type":"stat","value":20,"label":"Protocol Concepts on shelf"},{"type":"note","title":"OIP edge","text":"OIP difference: short share codes, scope, risk_ceiling, explain=1 — the token is the contract, not a session cookie."}],"home":true,"claims":[],"sources":[],"reviews":[],"extra":{},"has_traversal":false,"register":"standard","status":"published","revisions":1,"contributions":[],"provenance":[{"ts":"2026-07-15T04:20:52.499Z","model":"kimi-agent-import","action":"write","prompt":"","input":"","response":"","tokens_in":0,"tokens_out":0,"cost":0,"prev":"genesis","hash":"d9439b3866e347b42d4109644e5066b5755f0e3e2f5a8b1ede47271cca6d168c"},{"ts":"2026-07-15T06:24:52.500Z","model":"grok-build","action":"objection-patch","prompt":"","input":"","response":"","tokens_in":0,"tokens_out":0,"cost":0,"prev":"d9439b3866e347b42d4109644e5066b5755f0e3e2f5a8b1ede47271cca6d168c","hash":"fbadfeefa84ebe1ae2dc34042bb967f687903d3b1b9f3bfeeff17097ed4aeb5f"},{"ts":"2026-07-17T02:43:36.855Z","model":"owner","action":"voxel_divide","prompt":"","input":"what-is-capability-token","response":"43 DIVs from body (verbatim, roundtrip-checked)","tokens_in":0,"tokens_out":0,"cost":0,"prev":"fbadfeefa84ebe1ae2dc34042bb967f687903d3b1b9f3bfeeff17097ed4aeb5f","hash":"8ddfaebf01f2d8a615b410bc5e1e0042b8b201ecfdabdc749b3234ad38c26605"}],"energy":{"passes":3,"tokens_in":0,"tokens_out":0,"tokens_total":0,"cost_usd":0,"models":{"kimi-agent-import":1,"grok-build":1,"owner":1},"head":"8ddfaebf01f2d8a615b410bc5e1e0042b8b201ecfdabdc749b3234ad38c26605"},"posted_at":"2026-07-15T04:20:52.499Z","created_at":"2026-07-15T04:20:52.499Z","updated_at":"2026-07-17T02:43:36.855Z","machine":{"shape":"article.machine/v1","slug":"what-is-capability-token","kind":"article","read":{"human":"https://miscsubjects.com/a/what-is-capability-token","json":"https://miscsubjects.com/api/articles/what-is-capability-token","bundle":"https://miscsubjects.com/api/articles/what-is-capability-token/bundle?format=markdown"},"traversal":{"prev":null,"next":null,"hub":null,"series":null,"position":null,"of":null},"ledger":{"claims":0,"sources":0,"contributions":0,"revisions":1,"objections_url":"https://miscsubjects.com/api/articles/what-is-capability-token/objections","thread_state_url":"https://miscsubjects.com/api/protocol/thread-state?target=what-is-capability-token","proof_rule":"An action is proven by its ledger receipt, never by a 200 or a description."},"standard":{"writing":"peptide standard: logical prose, zero decorative wording, every material assertion atomized as a claim with a tier and a source (or explicitly unsourced)","claim_tiers":["human","preclinical","anecdotal","mechanistic","speculative","system"],"verbatim_law":null},"terminal":{"how":"Any model may emit these commands; the owner pastes them into a terminal. $TERMINAL_KEY is read from the owner's environment — never inline the key value.","claim_append":"curl -s -X POST https://miscsubjects.com/api/protocol/claim -H \"x-terminal-key: $TERMINAL_KEY\" -H 'content-type: application/json' -d '{\"slug\":\"what-is-capability-token\",\"text\":\"<one atomized claim>\",\"tier\":\"<human|preclinical|anecdotal|mechanistic|speculative|system>\",\"source_ids\":[],\"who_claims\":\"<model>\",\"rationale\":\"<why material>\"}'","source_append":"curl -s -X POST https://miscsubjects.com/api/protocol/sources -H \"x-terminal-key: $TERMINAL_KEY\" -H 'content-type: application/json' -d '{\"slug\":\"what-is-capability-token\",\"sources\":[{\"type\":\"review\",\"url\":\"<url>\",\"title\":\"<title>\",\"quote\":\"<verbatim quote>\",\"summary\":\"<one line>\"}]}'","objection":"curl -s -X POST https://miscsubjects.com/api/articles/what-is-capability-token/objections -H 'content-type: application/json' -d '{\"actor\":\"<model>\",\"objection\":\"<attack>\",\"surface\":\"S1-S8\",\"minimum_patch\":\"<patch>\"}'  # open intake, no key","thread_update":"curl -s -X POST https://miscsubjects.com/api/protocol/thread-update -H 'content-type: application/json' -d '{\"actor\":\"<model>\",\"target\":\"what-is-capability-token\",\"raw_text\":\"<material delta>\"}'  # open intake, no key","read_back":"curl -s https://miscsubjects.com/api/articles/what-is-capability-token | python3 -c 'import json,sys; d=json.load(sys.stdin); print(json.dumps(d[\"claims\"][-3:], indent=1))'"}},"representations":{"article":"/a/what-is-capability-token","json":"/api/articles/what-is-capability-token","markdown":"/api/articles/what-is-capability-token/bundle?format=markdown","skill":"/api/articles/what-is-capability-token/skill","topology":"/api/articles/what-is-capability-token/topology","versions":"/api/articles/what-is-capability-token/revisions","invocations":"/api/articles/what-is-capability-token/invocations"},"editorial_review":null,"editorial_audit":{"slug":"what-is-capability-token","ok":false,"issues":[{"code":"heading_filing_label","message":"section heading “Why It Matters” is a filing label that gives a cold reader no claim","replacement":"Replace “Why It Matters” with the concrete claim, event, or object introduced in that section."},{"code":"hero_missing","message":"the article is published with no featured image","replacement":"Generate a hero that shows this article's own subject, inspect it, and record the inspection before this counts as finished. An article with no image is not finished."}]},"body_hash":"91337204155e32aab3d182619704fa1d3822312b0cecd884513abc9b1b126dee"}}}