# DeepSeek Harness dsh-v0.1.2-alpha.4 — v0.1.2-alpha.4

- Product: DeepSeek Harness (https://whatsnew.fyi/product/deepseek-harness)
- Vendor: DeepSeek
- Date: 2026-09-01
- Version: dsh-v0.1.2-alpha.4
- Original notes: https://github.com/deepseek-ai/deepseek-harness/releases/tag/dsh-v0.1.2-alpha.4
- Permalink: https://whatsnew.fyi/product/deepseek-harness/releases/dsh-v0.1.2-alpha.4
- Labels: Pre-release

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **added** — Parent Agents and continuable child Agents can exchange follow-up messages through send_message, replacing the one-way report tool
- **changed** — Custom model discovery reuses Profile request headers
- **added** — Model catalog supports search and filtering
- **changed** — Interface corners, borders, turn navigation, and shadows refined
- **fixed** — Reduce rendering overhead in very long conversations during response streaming, interface layout, and navigation previews
- **added** — Enable web_fetch by default for Python SDK, Headless, ACP, and custom Profiles
- **removed** — Stop exposing the general-purpose workflow tool by default in Web PTC Mode
- **changed** — Replace Session.events with on-demand read APIs: seq, eventAt(), and snapshotEvents()
- **changed** — Distinguish SessionSeq and SessionLogOffset with strong types

[中文](#cn-v0.1.2-alpha.4) | [English](#en-v0.1.2-alpha.4)

<h3 id="cn-v0.1.2-alpha.4">新增功能</h3>

* 父 Agent 与可持续子 Agent 可通过 `send_message` 双向传递后续消息，取代单向 `report` 工具 @Dudu-0223

<h3>体验优化</h3>

* 自定义模型发现复用 Profile 请求头；模型目录支持搜索和筛选 @LegGasai
* 界面优化圆角、描边、轮次导航、投影效果 @yixiangihsiang, @LegGasai
* 改善超长会话在流式回复、界面布局、导航预览场景的渲染开销 @imccyu

<h3>其他变更</h3>

* Python SDK、Headless、ACP 与自定义 Profile 默认提供 `web_fetch` @koalazf99
* Web PTC Mode 默认不再向模型提供通用 `workflow` 工具 @koalazf99
* `Session.events` 被按需读取 API `seq`、`eventAt()` 和 `snapshotEvents()` 取代 @kermanx
* `SessionSeq` / `SessionLogOffset` 强类型区分，请开发者关注兼容性 @tianyicui

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<h3 id="en-v0.1.2-alpha.4">New Features</h3>

* Let parent Agents and continuable child Agents exchange follow-up messages through `send_message`, replacing the one-way `report` tool by @Dudu-0223

<h3>Improvements</h3>

* Reuse Profile request headers for custom model discovery; add search and filtering to the model catalog by @LegGasai
* Refine interface corners, borders, turn navigation, and shadows by @yixiangihsiang and @LegGasai
* Reduce rendering overhead in very long conversations during response streaming, interface layout, and navigation previews by @imccyu

<h3>Chores</h3>

* Enable `web_fetch` by default for the Python SDK, Headless, ACP, and custom Profiles by @koalazf99
* Stop exposing the general-purpose `workflow` tool by default in Web PTC Mode by @koalazf99
* Replace `Session.events` with on-demand read APIs: `seq`, `eventAt()`, and `snapshotEvents()` by @kermanx
* Distinguish `SessionSeq` and `SessionLogOffset` with strong types; developers should should pay attention to compatibility by @tianyicui

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Full Changelog: https://github.com/deepseek-ai/deepseek-harness/compare/dsh-v0.1.2-alpha.3...dsh-v0.1.2-alpha.4