The team's efforts in May continued to focus on making Sia easier to build with, more reliable to operate, and more useful for real-world applications. The biggest release note this month was hostd v2.9.0, which added support for RHP4 account pools and included fixes for host-announcement error handling and syncer rate limits on inbound peer connections.
May was also a milestone month for the Sia Storage Mobile App, which launched for iOS and Android at Consensus Miami. The launch marked an important step toward making user-owned storage more accessible to everyday users.
Users can still get 50 GB of Sia storage for free by downloading the Sia Storage Mobile App on iOS or Android.
On the grants side, the Foundation approved three new projects: OpenWeights, Sluby, and PrivRec. Together, these grants push Sia into several practical user-owned data categories: AI model distribution, video infrastructure, private screen recording, and personal calendar data. Progress also continued on SiCal, the Sia NFS Gateway, and Vup Vault, each of which reported meaningful work toward production-ready storage experiences built on Sia and indexd.
Development Updates
indexd: More Reliable Storage Infrastructure
Development on indexd this month focused on making Sia-powered apps more reliable behind the scenes. Several updates improved account funding, object syncing, host selection, and large storage migrations. The result is a more predictable foundation for apps that depend on Sia Storage.
- Account funding behavior was improved so accounts do not stop receiving funds simply because they have been downloading rather than uploading for a while.
- Object syncing was made more consistent by adjusting event timestamp precision and making contract queries more predictable.
- Host selection was tightened so hosts must be reachable over valid QUIC ports before being considered usable.
These changes reduce edge cases for developers and make Sia Storage feel more consistent for end users.
Sia Storage SDKs: Easier Development Across Languages
The Sia Storage SDKs also moved forward this month, with improvements aimed at making Sia easier to integrate into applications. The most important theme was developer experience: better language support, safer APIs, clearer progress reporting, and more resilient upload and download behavior.
- A Swift SDK release expands the path for native Apple platform integrations.
- Uploads and downloads now support per-shard progress callbacks, giving apps better visibility into what is happening during transfers.
- Downloads can now return a reader, making it easier for developers to stream data instead of forcing everything into a single write flow.
- Upload reliability improved through better recovery behavior, connection warmups, and the ability to race uploads across multiple hosts.
Together, these updates make the SDKs feel more like application-building tools and less like low-level infrastructure plumbing.
reed_solomon_rs: Faster Erasure Coding for Client-Side Storage
One of the month’s most important technical milestones was the new reed_solomon_rs implementation. Erasure coding is what keeps user data durable on Sia: files are split into shards, encoded with redundancy, and distributed across hosts so data can still be recovered even if some hosts go offline or slow down.
This work is especially important for Sia’s new architecture. For most of Sia’s history, erasure coding happened behind the scenes on servers. Now, client SDKs interact more directly with storage providers, which means user devices need to fetch, encrypt, erasure code, upload, download, and reconstruct data themselves. That includes browsers, where performance matters even more.
The result is a faster erasure-coding library built for the places Sia apps actually run: desktops, mobile devices, and browsers.
Benchmark | Previous Rust Option | New | Improvement |
Native encode, AVX2 | 1.1 GiB/s | 22.5 GiB/s | ~20x faster |
Native encode, GFNI | ~1.0 GiB/s | 24.6 GiB/s | ~25x faster |
Native encode, NEON | 1.1 GiB/s | 28.3 GiB/s | ~26x faster |
Native reconstruct, 10 data shards lost, AVX2 | 597 MiB/s | 7.2 GiB/s | ~12x faster |
Native reconstruct, 10 data shards lost, GFNI | 590 MiB/s | 8.2 GiB/s | ~14x faster |
Native reconstruct, 10 data shards lost, NEON | 593 MiB/s | 10.7 GiB/s | ~18x faster |
WASM encode | 209 MiB/s | 1.6 GiB/s | ~8x faster |
WASM reconstruct, 10 data shards lost | 131 MiB/s | 702 MiB/s | ~5x faster |
These improvements matter because faster erasure coding helps keep the user's device from becoming a bottleneck, making high-performance Sia storage more practical across native apps, mobile apps, and browsers.
s3d: S3 Compatibility and Easier Onboarding
s3d, Sia’s lightweight S3-compatible renter, made progress toward a smoother experience for developers and operators. Rather than requiring users to understand Sia-specific storage flows upfront, s3d continues to make Sia accessible through familiar S3-style workflows.
This month’s work improved the initial setup process by publishing an s3d Docker image, while upload packing made storage more efficient by bundling smaller uploads together before sending them to Sia. The onboarding wizard also received polish, helping new users get started with less friction.
The broader goal is simple: make Sia usable from tools and workflows that already understand S3, while still storing data on decentralized infrastructure.
hostd: RHP4 Account Pools and Better Network Limits
hostd v2.9.0 was the month’s key release, adding support for RHP4 account pools. Account pools let renters fund a pool once and attach multiple accounts to it, reducing the amount of capital sitting idle in individual account balances. This is especially useful for indexd workflows where many accounts may need access to shared funding.
The release also fixed an issue with syncer rate limiting so inbound peer connections are properly throttled alongside outbound ones, and it reduced irrelevant error noise before a host is announced.
explored, core libraries & renterd: Scalability and Stability
Several supporting components also received stability work this month. The most important explorer update was basic Postgres support in explored, which lays the groundwork for better scalability as explorer data grows.
The core libraries gained account pool support and improved stream behavior, while renterd fixed an issue where closing one transport could block others. These smaller updates help strengthen the infrastructure that Sia applications and services depend on.
Grant Program Updates
Newly Approved Grants
- OpenWeights: OpenWeights is a self-hostable, Hugging Face-compatible model hub backed by Sia instead of centralized S3 storage. The project will implement the Hub and Xet wire contracts used by existing
hf uploadandhf downloadworkflows, allowing users to redirectHF_ENDPOINTand store model bytes throughindexdon Sia without modifying Hugging Face clients. The grant covers a two-service Docker Compose stack with a Rust CAS service, Go gateway, Sia SDK integration, operator console, API key management, and end-to-end byte-identical upload/download testing. - Sluby: Sluby is a self-hosted, open-source video infrastructure platform built natively on Sia. It aims to give developers a Mux- or Cloudflare Stream-like experience while storing encrypted video artifacts on Sia through official SDKs and
indexd. The project includes resumable TUS uploads, FFmpeg transcoding, adaptive HLS playback, a byte-range-aware delivery gateway, REST APIs, a TypeScript SDK, React player, management Studio, documentation, testing, and production Docker Compose deployment. - PrivRec: PrivRec is a privacy-preserving browser-based screen and camera recorder built with the Sia JS SDK. Users will be able to record their screen, camera, or both directly in the browser, encrypt and upload recordings client-side, and generate shareable playback links without sending video through a central server. The grant covers onboarding, recording modes, device selection, Sia uploads, share links, recipient playback, recording history, deletion, account stats, self-hosting documentation, and a public release.
Progress Reports from Ongoing Grants
- SiCal: SiCal progressed from initial commit to a fully functional app this month. The team completed a Rust/Flutter bridge for Sia storage operations, local SQLite caching, full CRUD for calendar events, recurring event support, single and bulk ICS import, onboarding with embedded browser auth, timezone-aware display, and a robust sync engine. The developer also successfully imported more than 1,800 Google Calendar events and synced them to Sia in minutes. Next up are notifications, multiple calendar support, app store publication, and community feedback.
- Sia NFS Gateway - indexd & NFSv4: The Sia NFS Gateway project completed the planned core functionality of
sia-vfs, a virtual file system layer that provides a POSIX-like interface with local-first operation and eventual consistency. Work included chunk and blob support, the main VFS API and types, a SQLite-backed persistence layer, FlatBuffers-based zero-copy serialization, and in-memory caching for path and inode lookups. The team switched away from an unsuccessful graph database approach and will next finish remaining VFS touches, continue Milestone 3, and rebrand the project. - Vup Vault - Personal Backup, Sync & Archive: Vup Vault completed Milestone 4 end-to-end, with upload, read-back, and share-URL flows running against the live Foundation indexer at
sia.storage. The update introduceds5_store_indexd, which implements all Store trait methods via the Sia Storage SDK, ands5_store_packing, which bundles many small writes into larger packs before they reach the backend. The project also updated dependencies to clear RUSTSEC advisories and will next focus on deletion support, performance testing, Vup Web updates, documentation, and the publication of several crates.
Final Thoughts
May’s updates show Sia moving steadily toward a more developer-friendly and application-ready storage ecosystem. At the protocol and infrastructure layer, RHP4 account pools, better host checks, faster erasure coding, and improved SDK behavior all make Sia easier to build on and operate at scale. At the application layer, the grants program is pushing into categories that users already understand: model hosting, video infrastructure, screen recording, calendars, file systems, and personal backup.
The common thread across this month’s work is the growing practicality of user-owned data. What once sounded like a vision for the future is quickly becoming a toolkit for the present.
That’s all, folks!
Thanks for your continued support and dedication as we build the foundation of the decentralized future.
Take care, and see you next month.
Want important Sia updates delivered straight to your inbox?
Sign up for our newsletter and stay informed about new releases, partnerships, developer resources, and more!
