The State of Sia, January 2026

January’s updates focused on concrete quality-of-life improvements for operators and developers: faster initial sync for hosts, clearer limits and metrics, and a handful of targeted fixes across the stack.

On the release side, hostd v2.6.0 introduced Instant Sync (hostd --instant), so new hosts can start validating from a Utreexo-based checkpoint rather than replaying the full chain state. The release also added syncer bandwidth limits and stats, new alerts for failed contract funding, and disk I/O metrics—plus a partial-read improvement that drops the minimum sector segment read size from 4 MiB to 4 KiB by caching sector subtrees.

In our Grants Program, the Foundation approved two new grants—Vup Vault and Chi Voice—and received a progress report from SMB Indexer Support. The month also closed with a completed grant update from Lume Web – LBRY.

Development Updates

indexd: Contract Formation Edge Cases and Safer Upload Choices

Work on indexd focused on edge cases in contracts and on improving how the SDK decides where to upload.

Fixed an edge case in contract formation that caused excessive contract formations.
Added resumable uploads to the Go SDK.
Added a “good for upload” field to the usable-hosts response (based on stuck status and remaining storage).
Updated the SDK to avoid uploading to hosts marked as not good for upload.
Fixed an edge case when pinning sectors that could lead to lost sectors when a revision must be resynced.

renterd: Smaller Allocations in Pruning

This month, renterd made a focused internal cleanup to reduce allocations during pruning.

hostd: Instant Sync, Rate Limits, and Clearer Status

hostd v2.6.0 shipped Instant Sync and added several operator-facing controls and safeguards: syncer bandwidth limits, syncer bandwidth stats, an alert when contract formation, renewal, or refresh funding fails, and disk I/O tracking in metrics. It also reduced partial read overhead by caching sector subtrees.

Added syncer rate limits.
Return an error when database slices fail to decode (instead of silently masking decoding failures).
Changed writeSector to fsync sectors to disk synchronously.

The hostd UI saw two fixes aimed at improving the accuracy and clarity of the user interface:

Updated the address configuration copy to say ports may be configured
Fixed the announcement state so it reflects whether the host has actually announced (based on announcement index height).

explored: Backend Support for Unconfirmed Transaction Lookups

explored v0.1.3 expanded core API capabilities and operational configurability, including a new address checkpoint endpoint and configurable syncer peer limits. On the backend, support was added for looking up unconfirmed transactions.

Added [GET] /addresses/:address/checkpoint (returns the chain index where an address was first seen on-chain).
Made the syncer peer cap configurable.
Added backend support for looking up unconfirmed transactions.

coreutils: RHP4 Hardening

coreutils received protocol-level hardening work by replacing bytes.Buffer with a custom buffer implementation in RHP4.

s3d: Faster Downloads via Cached Metadata

s3d improved download behavior by using cached slab metadata instead of fetching it from the indexer, reducing dependency overhead and improving efficiency.

Grant Program Updates

Newly Approved Grants

Vup Vault – Personal Backup, Sync, & Archive with indexd: Vup Vault is a personal backup, sync, and archive tool built on S5 and powered by indexd. The grant funds a modern CLI and refreshed Vup Web interface, with the core deliverables s5_store_indexd, a new S5 storage backend built on the indexd SDK (sia-sdk-rs). The project aims to let S5 apps store data on Sia without requiring users to run renterd.
Chi-voice pilot: A focused pilot platform for collecting and organizing short audio recordings of underrepresented and indigenous languages. The grant supports a clean, auditable pipeline for collecting, labeling, and storing speech samples, demonstrating Sia as a content-addressed archival backend for reproducible language datasets.

Progress Reports from Ongoing Grants

SMB Indexer Support: The team added support for SMB dialects 2.1 and 3.0, refactored store handling, and laid the groundwork for a new config file to enable future indexd support. They also adjusted upload logic to handle Windows clients that send out-of-order writes.

Final Progress Reports

Lume Web – LBRY Integration (Revised): The team delivered an MVP LBRY integration via the portal system (including POST/TUS support and network pinning), along with UI integration and updates across related components. Their report also notes test findings on terminating blobs and inconsistent ordering of manifest JSON keys.

Final Thoughts

January’s updates reinforce a clear theme: reducing friction for both operators and developers. Instant Sync in hostd is a meaningful step toward faster, more approachable node onboarding, while the month’s reliability and correctness improvements across hostd, indexd, and explored continue to tighten the developer experience and operational predictability.

Meanwhile, the grants pipeline continues to push Sia into practical, user-facing territory—backup/sync workflows powered by indexd, SMB accessibility work that meets users where they are, and novel archival use cases like ethically sourced language datasets.

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.

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