Crate acdp 

acdp — Rust library for the Agent Context Distribution Protocol

Reference implementation of ACDP v0.1.0 Final (specification promoted to Final on 2026-05-19).

ACDP lets agents publish immutable, producer-signed context descriptors, retrieve and verify them locally, discover them by keyword, and follow signed references across registries.

Quick start — producer

// In production, load from secure storage; `generate` uses OsRng.
let key  = SigningKey::generate();
let prod = Producer::new(
    key,
    AgentDid::new("did:web:agents.example.com:my-agent"),
    "did:web:agents.example.com:my-agent#key-1",
);

let req = prod.publish_request()
    .title("Q1 snapshot")
    .context_type(ContextType::DataSnapshot)
    .visibility(Visibility::Public)
    .build()
    .unwrap();

println!("content_hash: {}", req.content_hash);

Quick start — consumer (feature = “client”)

use acdp::{client::{RegistryClient, VerifiedContext}, did::WebResolver, types::CtxId};

let client   = RegistryClient::new("https://registry.example.com")?;
let resolver = WebResolver::new();
let ctx_id   = CtxId("acdp://registry.example.com/…".into());
let ctx      = VerifiedContext::fetch(&client, &resolver, &ctx_id).await?;
println!("title: {}", ctx.body().title);

Re-exports

pub use acdp_types as types;

pub use acdp_producer as producer;

pub use acdp_validation as validation;

pub use acdp_verify as verify;

pub use acdp_did as did;

pub use acdp_safe_http as safe_http;

pub use acdp_client as client;client

Modules

crypto

Cryptographic primitives — re-exports the acdp-crypto crate plus the high-level verification helpers (which live in crate::verify, one layer up) under their historical crate::crypto::* paths.

error

Error types for the ACDP library.

limits

Network-policy constants shared by client and server code.

paginationserver

Cursor-pagination helpers for registry store backends.

profile

ACDP conformance profiles (RFC-ACDP-0001 §9.1).

registryserver

time

Time helpers shared by the producer builder and search-params formatter.

Structs

AgentDid

A Decentralized Identifier — v0.1.0 mandates did:web.

Body

The immutable stored body of an ACDP context (RFC-ACDP-0002).

CapabilitiesDocument

Registry capabilities document served at GET /.well-known/acdp.json.

ContentHash

sha256:<64-lowercase-hex> — content-addressable hash with algorithm prefix.

CtxId

acdp://<authority>/<uuid-v4> — registry-assigned context identifier.

DataRef

A reference to a piece of data the context describes.

FullContext

The full context object returned by GET /contexts/{ctx_id}.

KeyRevocation

Typed, shape-validated view of a key-revocation context body (RFC-ACDP-0014 §4).

LifecycleEvent

A lifecycle event (RFC-ACDP-0013 §4) — one entry of registry_state.lifecycle_events.

LineageId

lin:sha256:<64-lowercase-hex> — registry-assigned lineage identifier.

LogCheckpoint

A registry-signed checkpoint (signed tree head): the registry’s commitment that, as of timestamp, the log log_id has tree_size leaves and Merkle root root_hash (RFC-ACDP-0012 §6).

LogConsistencyProof

A consistency-mode GET /log/proof response (RFC-ACDP-0012 §8.2): the RFC 6962 §2.1.2 proof PROOF(first, D[second]) that the tree at first_tree_size is a prefix of the tree at second_tree_size — the history-rewrite detector. The verifier supplies its own retained root for first_tree_size (that retained root is the whole point, §9.2).

LogCosignature

A witness-signed cosignature of a transparency-log checkpoint (RFC-ACDP-0015 §4).

LogInclusion

An inclusion proof that one leaf is committed by a checkpointed transparency-log tree (RFC-ACDP-0012 §8.2, §9.1): the RFC 6962 §2.1.1 audit path for leaf_index at tree_size, together with the signed checkpoint it verifies against.

LogLeaf

One transparency-log leaf: the closed object binding one accepted publish event (RFC-ACDP-0012 §4).

PublishRequest

Wire-ready publish request body (POST /contexts).

PublishResponse

Successful publish response (HTTP 201).

RegistryState

Mutable, registry-derived state returned alongside the Body on retrieval.

SearchParams

Query parameters for GET /contexts/search.

SearchResponse

Response from GET /contexts/search.

WireError

Wire error envelope returned by the registry on all error responses.

WitnessSigner

Witness-side cosignature minting identity: the witness’s signing key plus the DID URL it is published under in the witness’s own DID document (RFC-ACDP-0015 §5, §9).

WitnessedCheckpoint

The identity-bearing subset of the RFC-ACDP-0012 §6 checkpoint the witness observed: {log_id, tree_size, root_hash, timestamp}, copied verbatim from the verified checkpoint (RFC-ACDP-0015 §4).

Enums

AcdpError

Top-level error type.

ContextType

Registered context types plus open-ended custom namespace.

DataRefType

Role of a data reference. Closed enum per acdp-data-ref.schema.json type.

LifecycleEventType

The lifecycle event kind — an open vocabulary (registries/lifecycle-event-types.md): v1 registers retracted and republished; unknown values matching the RFC-ACDP-0004 §4.1 pattern (^[a-z][a-z0-9_]*$, 1–64 chars) are tolerated with no effect on retraction state and round-trip verbatim — mirroring how Status handles unknown values. Registries MUST NOT accept unregistered values through the RFC-ACDP-0013 §6 endpoints in 0.3.0 (§7.3): openness is for future versions and consumers, not a free-form producer channel.

Location

Locator for DataRef.location — either a URI string or a structured locator object. See acdp-data-ref.schema.json location.oneOf.

RevocationTrustClass

The two trust classes of RFC-ACDP-0014 §5–§6. They carry different authority and MUST be reported distinguishably — never collapsed (§6).

Status

Registry-derived lifecycle status.

SupersessionReason

Sub-reason for AcdpError::SupersededTarget. Mirrors the details.reason values defined by acdp-error.schema.json.

Visibility

Visibility level of a context.

Constants

ACDP_SCHEMA_NAMESPACE

The JSON Schema namespace ($id prefix) for this protocol version, e.g. <ACDP_SCHEMA_NAMESPACE>/acdp-error.schema.json.

ACDP_VERSION

The ACDP protocol version this library implements.