Pinand

Pinand is a protocol and reference implementation for managing pinning of content in distributed, content-addressable networks. It defines a set of operations to pin and unpin content, assign retention policies, and coordinate replication across participating nodes. The aim is to provide predictable data durability while minimizing unnecessary storage use.

Core concepts include pin sets, retention policies, and verifiable manifests. A pin set groups related content under a policy that determines how long it remains pinned, how many replicas must exist, and when it may be evicted. Pin manifests are cryptographically signed to enable integrity verification across nodes.

Architecture: clients run a lightweight daemon that submits pin requests to pin servers and registries. A central or federated pin registry tracks pin sets, node capabilities, and policy definitions. Data transfer leverages standard content-addressable protocols, while the local state is persisted to ensure resilience against node restarts.

Origin and naming: the term pinand combines "pin" (to keep data durable) with a connector suggesting policy modules that can be added or chained. The project emphasizes modularity and interoperability rather than a single monolithic implementation.

History and status: pinand emerged in discussions among researchers and practitioners in 2023 and saw initial implementers release in 2024. It remains at an early stage, with several reference implementations and interoperability tests under way, but no formal standard has been adopted.

Applications: pinand is intended for long-term data archival, research data sharing, and distributed content delivery where durability guarantees are valued. It complements existing content-addressable storage by providing explicit retention contracts and verifiable pin states.