A Rust workspace for building secure, privacy-preserving applications using decentralised identity technologies. The TDK provides libraries and tools for DID resolution, DIDComm messaging, data integrity proofs, cryptographic primitives, and more.

Disclaimer: This project is provided "as is" without warranties or guarantees. By using this framework, users agree to assume all risks associated with its deployment and use, including implementing security and privacy measures in their applications. Affinidi assumes no liability for any issues arising from the use or modification of the project.

graph TD
    TDK["affinidi-tdk<br/><i>Unified entry point</i>"]

    subgraph Messaging["Affinidi Messaging"]
        SDK["messaging-sdk"]
        DIDCOMM["messaging-didcomm"]
        CORE["messaging-core"]
        TSP["affinidi-tsp"]
        MEDIATOR["messaging-mediator"]
        HELPERS["messaging-helpers"]
        TEXTCLIENT["messaging-text-client"]
    end

    subgraph Resolver["Affinidi DID Resolver"]
        CACHESDK["resolver-cache-sdk"]
        CACHESERVER["resolver-cache-server"]
        COMMON["did-common"]
        TRAITS["resolver-traits"]
        DIDSCID["did-scid"]
        DIDEXAMPLE["did-example"]
    end

    subgraph Common["TDK Common Libraries"]
        CRYPTO["affinidi-crypto"]
        ENCODING["affinidi-encoding"]
        SECRETS["secrets-resolver"]
        AUTH["did-authentication"]
        TDKCOMMON["tdk-common"]
        DI["data-integrity"]
        RDF["rdf-encoding"]
    end

    MP["affinidi-meeting-place"]

    TDK --> SDK
    TDK --> MP
    TDK --> DI
    TDK --> CACHESDK
    TDK --> DIDCOMM
    TDK --> AUTH
    TDK --> SECRETS
    TDK --> CRYPTO
    TDK --> TDKCOMMON
    TDK --> COMMON

    SDK --> DIDCOMM
    SDK --> CACHESDK
    DIDCOMM --> CORE
    TSP --> CORE
    MEDIATOR --> SDK
    MEDIATOR --> TSP
    HELPERS --> SDK
    HELPERS --> TSP
    TEXTCLIENT --> SDK
    MP --> AUTH
    MP --> TDKCOMMON

    CACHESDK --> COMMON
    CACHESDK --> TRAITS
    CACHESERVER --> CACHESDK
    DI --> CRYPTO
    DI --> RDF
    SECRETS --> CRYPTO
    SECRETS --> ENCODING
    AUTH --> SECRETS
    TDKCOMMON --> AUTH
    TDKCOMMON --> DI

The workspace is organised into dependency layers under crates/: core → identity → credentials / protocols / messaging → trust → applications, with the tdk facade on top.

A single crate that re-exports the TDK libraries behind feature flags so you can depend on one crate and enable only what you need.

Foundational primitives with no domain dependencies.

DID Document types and high-performance resolution with local and network caching (250k+ resolutions/sec cached).

W3C Verifiable Credentials and selective-disclosure formats.

OpenID for Verifiable Credentials (OID4VC) protocol family.

Secure, private messaging built on DIDComm v2 and TSP.

• Rust 1.90.0+ (2024 Edition)
• Redis 8.0+ (required for the messaging mediator)
• Docker (recommended for running Redis)

Add the unified TDK crate to your project:

[dependencies]
affinidi-tdk = "0.5"

Or depend on individual crates for finer control:

[dependencies]
affinidi-did-resolver-cache-sdk = "0.8"
affinidi-messaging-sdk = "0.15"
affinidi-data-integrity = "0.4"

use affinidi_did_resolver_cache_sdk::{config::ClientConfigBuilder, DIDCacheClient};

let config = ClientConfigBuilder::default().build();
let resolver = DIDCacheClient::new(config).await?;
let result = resolver.resolve("did:key:z6Mkr...").await?;
println!("DID Document: {:#?}", result.doc);

use affinidi_messaging_sdk::{ATM, config::Config};

let config = Config::builder()
    .with_my_did("did:peer:2...")
    .with_atm_did("did:peer:2...")
    .build()?;
let mut atm = ATM::new(config, vec![]).await?;
atm.send_ping("did:peer:2...", true, true).await?;

You can write messaging / DID / credential integration tests with no external infrastructure — no Redis, no network, no standing services. Two paths:

• Rust fixtures — pull a fixture crate in as a dev-dependency: affinidi-messaging-test-mediator for embedded mediators (TestMediator / TestEnvironment / TestTopology), and affinidi-tdk-test-support for did:web mocks, deterministic resolvers, seeded DIDs, and credential scenarios. A mediator is three lines; an issue/present/verify round trip is a handful.
• Language-agnostic — docker compose -f docker-compose.test.yml up a known-good mediator + Redis + did:web host with fixed TEST-ONLY identities and point any client at it.

Copy-paste scenarios for both paths are in the testing cookbook; the composed stack is documented in docs/testing/docker-compose.md.

This workspace's root Cargo.toml defines a non-trivial [patch.crates-io] table. Cargo's patch tables are only honoured by the workspace that defines them — when an external repository depends on any affinidi-* crate via a git rev or local path, that consumer must replicate the same patch table verbatim, or different parts of the dependency closure will end up resolving the affinidi-* crates from a mix of crates.io and the git/path source. Type-graph divergence shows up as confusing trait mismatches at compile time (expected MediatorACLSet, found MediatorACLSet).

This is a known cargo limitation — see rust-lang/cargo#4452.

The simplest approach is to depend on published versions only:

[dependencies]
affinidi-tdk = "0.7"
affinidi-messaging-sdk = "0.17"

[dev-dependencies]
affinidi-messaging-test-mediator = "0.1"

No patch table is needed — cargo resolves a single version of each affinidi-* crate from crates.io and the type graph is unified by construction.

If you need a patch that hasn't reached crates.io yet, pin the relevant affinidi-* crates to the same git rev, and mirror the workspace's patch table so transitive deps go through the same rev:

[patch.crates-io]
# Pick a single rev that all affinidi-* deps resolve through.
# Bump this when you bump any affinidi-* dep above.
affinidi-secrets-resolver = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
affinidi-did-resolver-cache-sdk = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
affinidi-did-common = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
affinidi-crypto = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
affinidi-encoding = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
affinidi-data-integrity = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
affinidi-messaging-didcomm = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
affinidi-messaging-sdk = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
affinidi-messaging-mediator = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
affinidi-messaging-mediator-common = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
affinidi-did-authentication = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
affinidi-tdk-common = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
affinidi-tdk = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
affinidi-meeting-place = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
affinidi-tsp = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
affinidi-did-web = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }
did-scid = { git = "https://github.com/affinidi/affinidi-tdk-rs", rev = "<rev>" }

The rev must match — and stay matched — to the version constraints in your own [dependencies]. If you bump affinidi-tdk above, bump the rev too; otherwise cargo may fall back to crates.io for crates not in the patch table.

A regenerator helper is provided to emit the patch block for a specific commit on this repo:

./tools/generate-consumer-patch.sh <git-rev>

If you face any issues or have suggestions, please don't hesitate to contact us using this link.

If you have a technical issue, you can open an issue directly in GitHub. Please include a title and clear description, as much relevant information as possible, and a code sample or executable test case demonstrating the expected behaviour.

Want to contribute? Head over to our CONTRIBUTING guidelines.

This project is licensed under the Apache-2.0 license.