{ scheme, locator, inclusionProof? }, namespaced
(anchor:sigil:…, anchor:eas:…). Unknown schemes are additive, never
breaking.
Arsenal — Agent Key Management and Credential Proxy. Issues ACTs,
manages an 11-step credential proxy pipeline with SSRF guards, provides
human-in-the-loop consent. Platform-agnostic credential injection for any
HTTP API.
BLAKE3 — Cryptographic hash function for content hashing, Merkle trees,
and content addressing in OAS. 256-bit output, significantly faster than
SHA-256 with equivalent security. Used for document integrity and audit
chains.
Capability — A scoped, time-bounded permission granted to an entity,
expressed as ACTs that can be delegated but never amplified. Least
privilege applies at every level.
Conformance Level — Graduated measure of implementation completeness.
L0: identifier parsing. L1: signature verification. L2: anchored lineage
path verification. L3: full operations including creation, delegation,
revocation, and FROST.
Core Protocol — The OpenAgent Core Protocol: transport-agnostic
challenge-response authentication. An agent proves its identity by signing
a server-issued challenge; no pre-registration, API keys, or OAuth flows.
The one normative authentication protocol.
Credential Proxy — Arsenal’s 11-step pipeline for secure credential
injection into HTTP requests on behalf of agents: SSRF guards, DNS
rebinding protection, request validation, credential retrieval,
hash-chained audit logging.
DID — Decentralized Identifier. Globally unique, self-sovereign,
W3C-specified. In OAS: did:oas:<namespace>:<kind>:<identifier>, derived
from an Ed25519 public key. Self-certifying, verifiable without any
registry.
DID Document — JSON document describing the entity behind a DID:
verification methods (public keys), service endpoints, and metadata.
Self-signed by the controller, extended with OAS entity kind and lineage
fields.
DID Resolution — Converting a DID string into its DID Document via the
8-stage pipeline: parse, cache, resolve, validate, verify, revocation,
lineage, return. Designed for offline use when cached.
Delegation — Granting a subset of capabilities to another entity via
signed proofs. Each delegation narrows the parent’s capabilities;
time-bounded and subject to the no-amplification rule.
Ed25519 — Elliptic curve signature algorithm (EdDSA) for all OAS
signatures. 64-byte signatures from 32-byte keys. Fast, timing-resistant,
formally verified. RFC 8032.
ENR — Enterprise Root. Entity kind representing an organizational
entity governed by corporate policy. Trust anchor for enterprise
deployments; delegates to agents, tools, and services.
Entity Kind — One of 11 classifications encoded in the DID string.
Roots (HMR, MHR, ENR) are trust anchors. Non-roots (Agent, Tool, Skill,
Workflow, Model, Dataset, Service, Agent Instance) represent ecosystem
roles.
FROST — Flexible Round-Optimized Schnorr Threshold signatures. t-of-n
key generation and signing for MHR entities; no single holder of the
complete key. Ceremonies use Noise XX transport.
HKDF — HMAC-based Key Derivation Function (RFC 5869). OAS uses
HKDF-SHA256 for deterministic child key derivation: parent key + path
produces child key pair. BIP-44/SLIP-0010 conventions.
HMR — Human Root. Fundamental trust anchor representing a single
human. Every lineage chain terminates at one. Provides human
accountability for all downstream autonomous actions.
JCS — JSON Canonicalization Scheme (RFC 8785). Deterministic JSON
serialization ensuring the same logical document always produces identical
bytes for signature computation.
Lineage Chain — Unbroken sequence of signed proofs tracing an entity to
a Human Root. Each proof: parent DID, child DID, purpose, constraints,
signature. Ensures human accountability.
Lineage Proof — Single signed attestation in a lineage chain:
parent/child DIDs, purpose (creation/delegation/authorization),
constraints, and an Ed25519 parent signature. Verified recursively.
MHR — Multi-Human Root. Entity kind using FROST threshold signatures
for t-of-n governance. Critical operations require a threshold of
participant signatures without any single key holder.
Multibase — Encoding format prefixing data with a character identifying
the scheme. OAS uses the z prefix (base58btc) for Ed25519 public keys;
multicodec prefix 0xed01 identifies the key type.
No-Amplification Rule — Security invariant: a child entity can never
possess more capabilities than its parent. Every delegation must narrow or
equal the parent’s capabilities. Prevents privilege escalation.
Resolver — Component implementing DID resolution: the 8-stage pipeline
with multiple transport backends (HTTP, DHT, direct), a local cache with
configurable TTLs, and negative caching.
Revocation — Invalidating a DID, delegation, or credential. DID:
deactivated flag. Delegations: sparse Merkle trees with cascading.
Credentials: issuer-published revocation lists and superseding
attestations.
Service Endpoint — URL or address in a DID Document for interacting
with the entity: API endpoints, messaging addresses, resolution endpoints,
or any network-accessible resource.
Sparse Merkle Tree — Data structure for efficient revocation checking:
inclusion and exclusion proofs for a large key space with logarithmic proof
sizes. Used for delegation and credential status.
Threshold Signing — t-of-n participants required for a valid signature.
OAS uses FROST for MHR; the resulting signature is indistinguishable from
standard Ed25519.