Carapace

Carapace is an open peer-to-peer protocol for encrypted, live-syncing friend-to-friend storage with social key recovery, built on the iroh networking stack. Files sync across your own devices like Dropbox; friends' machines store your data only as encrypted, content-addressed blobs they can hold and serve but not read. Every relationship is a bilateral, mutually-signed friendship (no groups, no transitive trust), and a threshold of trustees can reconstruct your key via Chela, using an extendable-split profile that lets the owner add or replace trustees without a full re-split. See carapace-protocol.md for the normative spec.

Crate map

Crate	Purpose
carapace-wire	Deterministic-CBOR codec, signing discipline, and the typed message/document registry (Appendix B).
carapace-crypto	Cryptographic suite 0x01: HKDF key tree, Ed25519 identity/delegation, FastCDC + XChaCha20-Poly1305 content sealing, HPKE sealed disclosure, Argon2id at-rest sealing.
carapace-vault	Vault identity, directory ingest into a sealed manifest + content-addressed chunk store, and reconstruction back to plaintext. Network-independent.
carapace-net	iroh integration: endpoint/ALPN binding, control-frame transport, Hello + anti-entropy sync, an iroh-blobs-backed chunk store.
carapace-recovery	Recovery-via-Chela orchestration: sealed split state, K_root/vault-root splitting and extension, share grants, the recovery ceremony.
carapace-friend	The friendship graph: contact cards, invite tickets, the ticket -> request -> accept handshake, unfriending.
carapace-replica	Consent-based replica placement and repair: an owner's replica set, a friend's replica-peer role, health/repair policy.
carapace-share	Share-health cadence on top of carapace-recovery's attestation primitives: trustee self-validation loop, owner attestation loop.
carapace-disclose	Selective disclosure (§7.4): build/open a FileGrant that hands out exactly chosen files' chunk keys to an explicit audience, and the owner-side fetch-authorization table.
carapaced	The daemon: binds an endpoint, serves the blob store + control protocol, holds vaults, runs the daemon-side disclosure/replica/PoR loops. Ships the carapaced binary.

Building

Requires a stable Rust toolchain (edition 2021).

Carapace depends on chela-engine, chela-bip39, and chela-share via path dependencies (../../../chela/... from crates/carapace-recovery), so the Chela repository must be checked out as a sibling of this repository:

some-parent-dir/
  Carapace/   <- this repo
  chela/      <- github.com/SecretSplitKit/Chela, branch main

mkdir some-parent-dir && cd some-parent-dir
git clone https://github.com/SecretSplitKit/Carapace.git Carapace
git clone https://github.com/SecretSplitKit/Chela.git chela
cd Carapace
cargo build --release

Verify

cargo fmt --all -- --check
cargo clippy --workspace --all-targets -- -D warnings
cargo test --workspace

Running the daemon

carapaced run --state-dir <PATH> [--publish <DIR> --vid <64-hex>]

--state-dir holds the daemon's persisted identity/state and is required. On start it binds the endpoint, serves the blob store and control protocol, and prints this device's node id and dialable address. With `--publish

`, it ingests and publishes that directory as a vault (generating a new vault id, or reusing one passed via `--vid`). It then idles, serving peers, until Ctrl-C.