Agent 4.2 · released 11 August 2026

Your working files, mirrored and versioned, without a file server.

Kestrel keeps laptops, the office NAS and offsite storage in agreement. The agent holds an open connection, ships changes as they happen, and survives a dropped link without starting the transfer over.

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No card required · 50 GB and three devices on the free tier

9 400devices syncing

62 TBmoved last month

90 daysversion history, all plans

99.95%availability, trailing quarter

How it works

Open connection

The agent keeps one long-lived connection per device instead of polling. A change on the laptop is visible on the NAS in about a second.

Chunked transfer

Files move in chunks with checksums. A dropped connection resumes where it stopped — a 40 GB project file does not restart from zero.

Versioned, not mirrored

Deleting on one device does not silently delete everywhere. Ninety days of history on every plan, restorable per file.

Conflicts kept

When two people edit the same file offline, both versions are preserved and flagged. Nothing is quietly overwritten.

Endpoints

The agent speaks the same HTTP API you can script against. One project token covers both directions.

POST /api/v2/sync
Authorization: Bearer <device token>
Content-Type: application/octet-stream

# resumable upload of a large asset
curl -C - -T project-master.psd \
  "https://kestrelsync.com/api/v2/sync?path=/design/project-master.psd"

Range requests are supported in both directions, so partial restores do not require pulling the whole snapshot.

Pricing

Free

50 GB
3 devices
90-day history

Team

$18/mo

2 TB
unlimited devices
NAS connector
priority transfer

Studio

$64/mo

20 TB
offsite replica
SSO and audit log
dedicated transfer lane

Status

Sync transport	Operational
Version history	Operational
NAS connector	Operational
Web dashboard	Operational

Last incident: 2 July, delayed history indexing for 41 minutes. No data loss.