seek://news/dsh-v0-1-2-alpha-2-to-alpha-5
Four Prereleases in Four Days: v0.1.2-alpha.2 Through alpha.5
TL;DR
DeepSeek Harness shipped v0.1.2-alpha.2 through alpha.5 on four consecutive days (2026-08-30 to 09-02). Mostly long-conversation performance work, but the train also removes the SQLite session backend, replaces Session.events with on-demand read APIs, defaults web_fetch on across SDK, Headless, ACP and custom Profiles, swaps report for bidirectional send_message, and closes with an upgrade hotfix.
After the single-release gap covered by Upstream Ships v0.1.2-alpha.1: Code Mode Becomes PTC Mode, Public WebFetch On by Default, upstream published four releases on four consecutive days: v0.1.2-alpha.2 (2026-08-30), v0.1.2-alpha.3 (08-31), v0.1.2-alpha.4 (09-01) and v0.1.2-alpha.5 (09-02). Most of it is polish, but the train carries changes that deserve a closer read before upgrading.
The through-line: long conversations
The first three releases work the same seam. alpha.2 improves processing of long conversation histories and high-volume live messages. alpha.3 cuts memory use and speeds up syntax highlighting when rendering long conversations, and teaches the right-hand navigation to preview and jump to paginated turns that are not even loaded yet. alpha.4 reduces rendering overhead in very long conversations across response streaming, layout and navigation previews. The commit log on release day is more of the same — streaming updates published on a frame cadence, scroll geometry sampling throttled, history windows paged before rendering. This is a client learning to stay responsive at scales it did not have to handle in July.
Read before you upgrade
- SQLite sessions are gone (alpha.3). The optional SQLite session persistence backend was removed. Per the notes, existing content is not deleted, and exporting means running an older version. If you relied on that backend, the notes give you an exit, not a destination.
- The session event API is reshaped (alpha.4).
Session.eventsis replaced by on-demand read APIs —seq,eventAt(),snapshotEvents()— andSessionSeq/SessionLogOffsetbecome distinct strong types. The notes flag this one explicitly: developers should pay attention to compatibility. - Upgrades themselves broke (alpha.5). The newest release is a single-item hotfix: upgrading from
0.1.1-rc.2or0.1.2-alpha.3could prevent the app from starting or make session titles disappear from the list. A same-week hotfix for upgrade failures is the clearest possible statement of what pre-release channel means here. - The channel itself churns (alpha.2).
SessionEvent.ignorablewas removed in alpha.1 and restored in alpha.2. If your code consumes session events on the alpha track, treat every alpha bump as potentially touching event types.
Defaults keep moving
alpha.1 turned public WebFetch on by default. alpha.4 extends the same default to the Python SDK, Headless, ACP and custom Profiles, and stops exposing the general-purpose workflow tool in Web PTC Mode by default. Neither change is buried: both sit in the Chores sections. Combined with alpha.2’s connection-failure display with automatic retries and immediate reconnect, the pattern is a harness that keeps adjusting what a fresh install can reach without asking.
Agent-to-agent, in both directions
alpha.4’s single New Features entry: parent agents and continuable child agents exchange follow-up messages through send_message, replacing the one-way report tool. Everything else in alpha.2 and alpha.3’s feature rows is interface-side — connection status, schedules in the conversation header, plugin grouping by scope.
Still the pre-release channel
The releases API now lists nine published releases; every one, this train included, is flagged prerelease. Live repo metadata stays in the site’s build-time snapshot and stats page — this article cites no point-in-time star counts.
Official references