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Affinidi Trust Development Kit (TDK)

Repo: github.com/affinidi/affinidi-tdk-rs

The Affinidi TDK is a comprehensive Rust toolkit providing identity, messaging, and credential primitives for the OpenVTC ecosystem. It’s the foundational library that higher-level projects depend on for DID resolution, secure communication, and cryptographic operations.

Key Components

DID Resolution (affinidi-did-resolver)

High-performance DID resolution with local and network caching:

  • 250k+ resolutions per second from cache
  • Pluggable DID method support (did:webvh, did:key, did:peer, did:scid)
  • Integrates with didwebvh-rs for webvh verification

Messaging (affinidi-messaging)

Secure messaging built on DIDComm v2.1:

  • SDK, mediator/relay service, and terminal chat client
  • Authcrypt and anoncrypt encryption modes
  • Message forwarding and routing
  • Production features: circuit breakers, rate limiting, graceful shutdown

Trust Spanning Protocol (affinidi-tsp)

Implementation of the Trust over IP TSP specification:

  • HPKE-Auth encryption
  • CESR binary encoding
  • A leaner alternative to DIDComm for certain use cases

Cryptographic Primitives

  • Ed25519, P-256, secp256k1 key support
  • W3C Data Integrity proofs (EdDSA JCS 2022, EdDSA RDFC 2022)
  • Multibase/multicodec encoding
  • RDF canonicalization

Credentials (affinidi-sd-jwt)

Selective Disclosure JWT (SD-JWT) per RFC 9901 — issue, present, and verify credentials with selective claim disclosure.

Meeting Place (affinidi-meeting-place)

Discovery and connection service using DIDs.

Role in the Ecosystem

The TDK is the Swiss Army knife that everything else depends on:

Recent Development

The TDK is a multi-crate workspace; entries below name the affected crate. Direction is toward production readiness with stronger security guarantees and better modularity. Implementation is evolving quickly; treat low-level APIs as in flux.

mediator 0.15.2 — 2026-05-07

  • Foolproof api_prefix normalisation

mediator 0.15.1 + test-mediator 0.2.2 — 2026-05-05

  • Routing fix
  • mediator-common feature gating
  • ACL / admin surface

affinidi-messaging-test-mediator initial publication — 2026-05-04

  • Promoted from in-tree fixture to published crate with third-party ergonomics
  • Self-loopback routing fix
  • Types relocation
  • local_dids setter and affinidi-messaging-mediator boot wrapper for integration tests
  • Downstream openvtc workspace immediately migrated to consume this, dropping ~400 lines of fixture code

mediator 0.14.0 — 2026-05-04 — pluggable storage + unified secret backend + setup wizard

  • Pluggable storage backends
  • Unified secret backend
  • New dedicated mediator-setup wizard package at crates/messaging/affinidi-messaging-mediator/tools/mediator-setup
  • Wizard iterated in subsequent 0.14.1 / 0.15.x point releases: sealed-handoff webvh-server prompt restructure; pnm --create-context emission; Open/Closed network mode selection; fjall data-dir confirmation; security hygiene (zeroize sealed-handoff secrets on drop, shell-quote operator fields, restrict sensitive writes to 0o600, deny_unknown_fields)

affinidi-tdk-common v0.6.0 — 2026-05-01

  • Hardening + API tightening release
  • Workspace-wide bump to consume it across crates

affinidi-tdk-rs v0.5.4 — 2026-04-18 — post-quantum cryptography + data-integrity API refactor

  • PQC support across the workspace
  • Data-integrity API refactor
  • New affinidi-did-web crate
  • MSRV bumped to 1.94

affinidi-messaging 0.1.5 / 0.2.0 — 2026-04-13 — DIDComm service usability + outbound messaging

  • Improved API ergonomics for the DIDComm service
  • New outbound-messaging path

DIDComm 0.13.0 — 2026-04-09 — VTA integration for centralized key management

  • Mediator / DIDComm service can delegate signing to the VTA

See also: didwebvh-rs, verifiable-trust-agent, didcomm

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