DeepSeek Harness v0.1.2-alpha.3: Long Chats & SQLite Removal

DeepSeek released dsh-v0.1.2-alpha.3 on September 1, 2026 in China Standard Time. It continues alpha.2's usability work with improvements to long conversations, image attachments, and interface details. It also removes the optional SQLite Session persistence backend, which is the most important change to review before upgrading.

The short version

Alpha.3 is more comfortable for long and image-heavy sessions. Users who configured the SQLite Session backend should not upgrade over their working environment without preparation: the release notes say existing data is not deleted, but it must be exported with an older version.

Release status

Pin the full version when reproducing this historical build:

npx @deepseek-ai/[email protected] web

The migration warning: SQLite Session storage is removed

Alpha.3 removes the optional SQLite Session persistence backend. The official notes explicitly say that existing content is not deleted and should be exported with an older version.

“Not deleted” does not mean “still readable by the new version.” If you deliberately enabled the SQLite backend:

1. Preserve the working version and back up the original data.
2. Export Sessions while the older version can still read them.
3. Test alpha.3 with an isolated configuration and its default Session storage.
4. Confirm the export is readable before migrating an everyday environment.

Most users who never selected the optional backend will not need this migration, but checking the active Profile and persistence configuration is still prudent.

Long-conversation improvements

The right-hand turn navigator can now preview and jump to paginated turns that have not yet been loaded. The release also reduces memory use in long conversations and improves syntax-highlighting responsiveness.

These changes matter most to Sessions with many tool calls, large code blocks, or multi-Agent activity. They improve client-side navigation and rendering; they do not imply a larger model context window, lower API charges, or expanded server storage.

Image delivery and reading fixes

Images appended or queued while a conversation is running are echoed and delivered more reliably. Follow-up messages to continuable child Agents can carry images too.

read_image can also detect image content at attachment paths without filename extensions. That is useful for clipboard input, content-addressed storage, and temporary attachments that do not retain .png or .jpg suffixes.

Other fixes worth knowing

• Tab completes the highlighted slash command while the command menu is open.
• Backend stalls are less likely to be misclassified as network disconnections.
• The active Schedule list no longer shifts or overflows as easily in narrow viewports.
• Permission labels have clearer multilingual wording.

Should you upgrade?

Later alpha.4 and alpha.5 builds now exist. A new installation normally does not need alpha.3 specifically; this article remains useful for understanding the sequence and diagnosing an alpha.2-to-alpha.3 transition.

Related reading

• DeepSeek Harness v0.1.2-alpha.2: Reconnects, Presets and Token Stats
• DeepSeek Harness v0.1.2-alpha.4: Two-Way Agent Messaging and Session API Changes
• DeepSeek Harness security guide

Frequently asked questions

Does alpha.3 delete existing SQLite Sessions?

The official notes say existing content is not deleted, but the optional SQLite backend is removed. Export anything you need with an older version that still supports it.

Is alpha.3 stable?

No. GitHub marks it as a pre-release. Pin the version and test it in isolation.

Do the long-chat improvements reduce model token usage?

That cannot be inferred from the release notes. They describe client navigation, memory use, and syntax highlighting—not model context or billing changes.