diff --git a/.trellis/scripts/common/active_task.py b/.trellis/scripts/common/active_task.py
index c3caac0db..97a7784a6 100644
--- a/.trellis/scripts/common/active_task.py
+++ b/.trellis/scripts/common/active_task.py
@@ -55,6 +55,7 @@
     "kimi",
     "zcode",
     "snow",
+    "dsh",
 }
 
 # Every name below records how it was checked. Do NOT add a name by analogy
@@ -64,6 +65,15 @@
 # only "evidence" behind them. A platform with no verified name belongs in no
 # table; it resolves through TRELLIS_CONTEXT_ID or its hook/plugin bridge.
 _ENV_SESSION_KEYS: tuple[tuple[str, tuple[str, ...]], ...] = (
+    # REAL (reported 2026-08-13 against DSH 0.1.0-rc.6 by @SajoLuo, from a live
+    # run: DSH exports DSH_SESSION_ID plus DSH_SHELL=1 into its managed shell).
+    # MUST STAY FIRST. A DSH session can inherit an outer host's identity — a
+    # DSH launched from Codex still carries CODEX_THREAD_ID — and the untargeted
+    # lookup below walks this table in order, so any earlier entry would claim
+    # the session and write a foreign `codex_<thread>` pointer for DSH work.
+    # DSH_SESSION_ID is the only name here no other vendor sets, so first place
+    # is safe: it cannot mis-claim a non-DSH session.
+    ("dsh", ("DSH_SESSION_ID",)),
     # REAL, undocumented (verified 2026-08-05 in a live Claude Code 2.1.221 bash
     # child; absent from code.claude.com/docs/en/env-vars). CLAUDE_SESSION_ID
     # was removed here — verified absent from that same live environment.
diff --git a/.trellis/workflow.md b/.trellis/workflow.md
index bf3d1c136..158142e16 100644
--- a/.trellis/workflow.md
+++ b/.trellis/workflow.md
@@ -280,13 +280,13 @@ When a user request matches one of these intents inside an active task, route fi
 
 [/Claude Code, Cursor, OpenCode, codex-sub-agent, Kiro, Gemini, Qoder, CodeBuddy, Copilot, Droid, Pi, Oh My Pi, ZCode, Snow, Reasonix, Trae, Grok, Kimi Code]
 
-[codex-inline, Kilo, Antigravity, Devin]
+[codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 - Planning or unclear requirements -> `trellis-brainstorm`.
 - Before editing -> `trellis-before-dev`; after editing -> `trellis-check`.
 - Repeated debugging -> `trellis-break-loop`; spec updates -> `trellis-update-spec`.
 
-[/codex-inline, Kilo, Antigravity, Devin]
+[/codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 ### Guardrails
 
@@ -363,11 +363,11 @@ Spawn the research sub-agent:
 
 [/Claude Code, Cursor, OpenCode, codex-sub-agent, Kiro, Gemini, Qoder, CodeBuddy, Copilot, Droid, Pi, Oh My Pi, ZCode, Snow, Reasonix, Trae, Grok, Kimi Code]
 
-[codex-inline, Kilo, Antigravity, Devin]
+[codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 Do the research in the main session directly and write findings into `{TASK_DIR}/research/`. `codex-inline` is the explicit mode that keeps work in the main session.
 
-[/codex-inline, Kilo, Antigravity, Devin]
+[/codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 **Research artifact conventions**:
 - One file per research topic (e.g. `research/auth-library-comparison.md`)
@@ -427,11 +427,11 @@ Skip this step only when both files already have real curated entries.
 
 [/Claude Code, Cursor, OpenCode, codex-sub-agent, Kiro, Gemini, Qoder, CodeBuddy, Copilot, Droid, Pi, Oh My Pi, ZCode, Snow, Reasonix, Trae, Grok, Kimi Code]
 
-[codex-inline, Kilo, Antigravity, Devin]
+[codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 Skip this step. Context is loaded directly by the `trellis-before-dev` skill in Phase 2.
 
-[/codex-inline, Kilo, Antigravity, Devin]
+[/codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 #### 1.4 Activate task `[required · once]`
 
@@ -515,7 +515,7 @@ The platform prelude auto-handles the context load requirement:
 
 [/Kiro]
 
-[codex-inline, Kilo, Antigravity, Devin]
+[codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 1. Load the `trellis-before-dev` skill to read project guidelines
 2. Read `{TASK_DIR}/prd.md`, then `design.md` if present, then `implement.md` if present
@@ -523,7 +523,7 @@ The platform prelude auto-handles the context load requirement:
 4. Implement the code per reviewed artifacts
 5. Run project lint and type-check
 
-[/codex-inline, Kilo, Antigravity, Devin]
+[/codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 #### 2.2 Quality check `[required · repeatable]`
 
@@ -543,7 +543,7 @@ The check agent's job:
 
 [/Claude Code, Cursor, OpenCode, codex-sub-agent, Kiro, Gemini, Qoder, CodeBuddy, Copilot, Droid, Pi, Oh My Pi, ZCode, Snow, Reasonix, Trae, Grok, Kimi Code]
 
-[codex-inline, Kilo, Antigravity, Devin]
+[codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 Load the `trellis-check` skill and verify the code per its guidance:
 - Spec compliance
@@ -552,7 +552,7 @@ Load the `trellis-check` skill and verify the code per its guidance:
 
 If issues are found → fix → re-check, until green.
 
-[/codex-inline, Kilo, Antigravity, Devin]
+[/codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 **Final pass (before Phase 3.4 commit)**: the last 2.2 of a task must run full-scope, not just on the latest implement chunk. List all affected packages with `python3 ./.trellis/scripts/get_context.py --mode packages`, then load each package's spec index Quality Check section. This catches cross-layer / multi-package issues a mid-iteration local 2.2 cannot.
 
diff --git a/README.md b/README.md
index bd94f3de0..fd6a38cff 100644
--- a/README.md
+++ b/README.md
@@ -44,7 +44,7 @@
 | **Task-centered workflow** | Keep PRDs, implementation context, review context, and task status in `.trellis/tasks/` so AI work stays structured. |
 | **Project memory** | Journals in `.trellis/workspace/` preserve what happened last time, so each new session starts with real context. |
 | **Team-shared standards** | Specs live in the repo, so one person's hard-won workflow or rule can benefit the whole team. |
-| **Multi-platform setup** | Bring the same Trellis structure to 21 AI coding platforms instead of rebuilding your workflow per tool. |
+| **Multi-platform setup** | Bring the same Trellis structure to 22 AI coding platforms instead of rebuilding your workflow per tool. |
 
 ## Prerequisites:
 
diff --git a/README_CN.md b/README_CN.md
index 4f8eb1c51..8a770b0ba 100644
--- a/README_CN.md
+++ b/README_CN.md
@@ -44,7 +44,7 @@
 | **任务驱动工作流** | PRD、实现上下文、审查上下文与任务状态统一存放于 `.trellis/tasks/`，AI 开发过程保持结构化、可追溯。 |
 | **项目记忆** | `.trellis/workspace/` 中的工作日志（journal）会保留上一次会话的脉络，因此每次新会话都能基于真实上下文开始。 |
 | **团队共享标准** | Spec 随仓库一同版本化，个人总结出的规则与流程可以直接成为整个团队的基础设施。 |
-| **多平台复用** | 同一套 Trellis 结构覆盖 21 个 AI coding 平台，无需为每个工具单独搭建工作流。 |
+| **多平台复用** | 同一套 Trellis 结构覆盖 22 个 AI coding 平台，无需为每个工具单独搭建工作流。 |
 
 ## 前置要求
 
diff --git a/docs-site b/docs-site
index dabf17c13..1066c727b 160000
--- a/docs-site
+++ b/docs-site
@@ -1 +1 @@
-Subproject commit dabf17c13e9023e53e284873b27beaf76d23dc89
+Subproject commit 1066c727bee7e7cfb475738b74b5f48e838d1618
diff --git a/marketplace b/marketplace
index 1329c65b9..d286b2ce8 160000
--- a/marketplace
+++ b/marketplace
@@ -1 +1 @@
-Subproject commit 1329c65b949ed03beb0970ac34b5b288bca1a41a
+Subproject commit d286b2ce8cd899b40de75446c24efacf1abd7bae
diff --git a/packages/cli/src/cli/index.ts b/packages/cli/src/cli/index.ts
index d87046671..830de0324 100644
--- a/packages/cli/src/cli/index.ts
+++ b/packages/cli/src/cli/index.ts
@@ -84,6 +84,7 @@ program
   .option("--codebuddy", "Include CodeBuddy commands")
   .option("--copilot", "Include GitHub Copilot hooks")
   .option("--droid", "Include Factory Droid commands")
+  .option("--dsh", "Include DeepSeek Harness (dsh) skills")
   .option("--pi", "Include Pi Agent extension assets")
   .option("--reasonix", "Include Reasonix skills")
   .option("--zcode", "Include ZCode commands")
diff --git a/packages/cli/src/commands/init.ts b/packages/cli/src/commands/init.ts
index 6b51eb2f8..47fcef378 100644
--- a/packages/cli/src/commands/init.ts
+++ b/packages/cli/src/commands/init.ts
@@ -1017,6 +1017,7 @@ interface InitOptions {
   codebuddy?: boolean;
   copilot?: boolean;
   droid?: boolean;
+  dsh?: boolean;
   pi?: boolean;
   reasonix?: boolean;
   zcode?: boolean;
diff --git a/packages/cli/src/configurators/dsh.ts b/packages/cli/src/configurators/dsh.ts
new file mode 100644
index 000000000..9ce5b8eed
--- /dev/null
+++ b/packages/cli/src/configurators/dsh.ts
@@ -0,0 +1,85 @@
+/**
+ * DeepSeek Harness (dsh) configurator.
+ *
+ * dsh is a class-2 pull-based platform (agentCapable, no shipped
+ * session-start hook, no project-level hooks/settings Trellis may write).
+ * The dsh agent loads skills by name through its skill-loader tool and
+ * discovers them from the project roots `<projectRoot>/.dsh/skills`
+ * (rank 100) and `<projectRoot>/.agents/skills` (rank 200). Two output
+ * paths:
+ * - `.agents/skills/` — workflow + bundled skills, written via the NEUTRAL
+ *   resolver so the files stay byte-identical to Codex/Gemini/Pi/Kimi
+ *   writes into the same shared root.
+ * - `.dsh/skills/` — dsh-private user-invocable entry skills
+ *   (`trellis-start` / `trellis-continue` / `trellis-finish-work`),
+ *   platform-resolved (`--platform dsh`, `trellis-<name>` skill refs), in
+ *   dsh's own highest-rank project skill root.
+ * - `.dsh/DSH.md` — operator guide; also gives the platform a
+ *   configDir-owned tracked file so `trellis platforms` / `uninstall`
+ *   can detect and scope dsh.
+ *
+ * dsh ships no project-level sub-agent definition surface, so no
+ * trellis-implement / trellis-check / trellis-research agent prompts are
+ * written; implement/check/research run inline through the workflow skills.
+ */
+
+import { AI_TOOLS } from "../types/ai-tools.js";
+import { getDshGuide } from "../templates/dsh/index.js";
+import {
+  collectSkillTemplates,
+  resolveAllAsSkills,
+  resolveBundledSkills,
+  resolveSkillsNeutral,
+} from "./shared.js";
+
+/**
+ * Command templates that become user-invocable dsh skills
+ * (`trellis-start` / `trellis-continue` / `trellis-finish-work`). dsh has
+ * no slash-command palette, so the session-boundary commands are delivered
+ * as SKILL.md files in `.dsh/skills/`.
+ */
+const DSH_COMMAND_SKILL_NAMES = new Set([
+  "trellis-start",
+  "trellis-continue",
+  "trellis-finish-work",
+]);
+
+/** Session-boundary commands resolved as dsh skills (dsh-private root, so
+ *  platform-specific `{{CLI_FLAG}}` / `{{CMD_REF}}` resolution is correct). */
+function resolveDshCommandSkills(): ReturnType<typeof resolveAllAsSkills> {
+  const ctx = AI_TOOLS.dsh.templateContext;
+  return resolveAllAsSkills(ctx).filter((skill) =>
+    DSH_COMMAND_SKILL_NAMES.has(skill.name),
+  );
+}
+
+/**
+ * The dsh file set — written at init and diffed by `trellis update`.
+ */
+export function collectDshTemplates(): Map<string, string> {
+  const ctx = AI_TOOLS.dsh.templateContext;
+  const files = new Map<string, string>();
+
+  // 1. Workflow + bundled skills → shared `.agents/skills/` (neutral
+  //    rendering, byte-identical to Codex/Gemini/Pi/Kimi writes).
+  for (const [filePath, content] of collectSkillTemplates(
+    ".agents/skills",
+    resolveSkillsNeutral(ctx),
+    resolveBundledSkills(ctx),
+  )) {
+    files.set(filePath, content);
+  }
+
+  // 2. Commands-as-skills → `.dsh/skills/` (dsh-native project root).
+  for (const [filePath, content] of collectSkillTemplates(
+    ".dsh/skills",
+    resolveDshCommandSkills(),
+  )) {
+    files.set(filePath, content);
+  }
+
+  // 3. Operator guide → `.dsh/DSH.md`.
+  files.set(".dsh/DSH.md", getDshGuide());
+
+  return files;
+}
diff --git a/packages/cli/src/configurators/index.ts b/packages/cli/src/configurators/index.ts
index d3415415d..a83c5f550 100644
--- a/packages/cli/src/configurators/index.ts
+++ b/packages/cli/src/configurators/index.ts
@@ -35,6 +35,7 @@ import { collectQoderTemplates } from "./qoder.js";
 import { collectCodebuddyTemplates } from "./codebuddy.js";
 import { collectCopilotTemplates } from "./copilot.js";
 import { collectDroidTemplates } from "./droid.js";
+import { collectDshTemplates } from "./dsh.js";
 import { collectPiTemplates } from "./pi.js";
 import { collectReasonixTemplates } from "./reasonix.js";
 import { collectZcodeTemplates, configureZcode } from "./zcode.js";
@@ -98,6 +99,7 @@ const PLATFORM_FUNCTIONS: Record<AITool, PlatformFunctions> = {
   codebuddy: fromTemplates(collectCodebuddyTemplates),
   copilot: fromTemplates(collectCopilotTemplates),
   droid: fromTemplates(collectDroidTemplates),
+  dsh: fromTemplates(collectDshTemplates),
   pi: fromTemplates(collectPiTemplates),
   reasonix: fromTemplates(collectReasonixTemplates),
   zcode: { configure: configureZcode, collectTemplates: collectZcodeTemplates },
diff --git a/packages/cli/src/templates/common/bundled-skills/trellis-meta/references/platform-files/platform-map.md b/packages/cli/src/templates/common/bundled-skills/trellis-meta/references/platform-files/platform-map.md
index 026773f58..f66e1313f 100644
--- a/packages/cli/src/templates/common/bundled-skills/trellis-meta/references/platform-files/platform-map.md
+++ b/packages/cli/src/templates/common/bundled-skills/trellis-meta/references/platform-files/platform-map.md
@@ -19,6 +19,7 @@ This page lists common Trellis file locations in a user project by platform. Whe
 | CodeBuddy | `--codebuddy` | `.codebuddy/` | `.codebuddy/skills/` | `.codebuddy/agents/` | `.codebuddy/hooks/` + `.codebuddy/settings.json` |
 | GitHub Copilot | `--copilot` | `.github/` | `.github/skills/` | `.github/agents/` | `.github/copilot/hooks/` + prompts |
 | Factory Droid | `--droid` | `.factory/` | `.factory/skills/` | `.factory/droids/` | `.factory/hooks/` + settings |
+| DeepSeek Harness (dsh) | `--dsh` | `.dsh/` | `.agents/skills/` (shared) + `.dsh/skills/` (entry skills) | None (workflow skills run implement/check inline) | None (class-2 pull-based; no project hooks/settings) |
 | Pi Agent | `--pi` | `.pi/` | `.agents/skills/` | `.pi/agents/` | `.pi/extensions/trellis/` (native `trellis_subagent` tool) + `.pi/settings.json` |
 | Trae IDE | `--trae` | `.trae/` | `.trae/skills/` | `.trae/agents/` | `.trae/hooks/` + `.trae/hooks.json` |
 | Reasonix | `--reasonix` | `.reasonix/` | `.reasonix/skills/` | None — sub-agents are skills with `runAs: subagent` frontmatter | None |
@@ -73,7 +74,7 @@ When changing behavior, inspect workflows and skills first. Do not assume Trelli
 
 ### Shared `.agents/skills/`
 
-Codex, Gemini CLI, Pi Agent, and Kimi Code write the shared `.agents/skills/` layer. Some tools that support agentskills.io can also read this directory. If the user wants multiple compatible tools to share one skill, consider `.agents/skills/` first, but do not assume every platform reads it. ZCode keeps Trellis-managed skills under `.zcode/skills/`.
+Codex, Gemini CLI, Pi Agent, Kimi Code, and DeepSeek Harness (dsh) write the shared `.agents/skills/` layer. Some tools that support agentskills.io can also read this directory. If the user wants multiple compatible tools to share one skill, consider `.agents/skills/` first, but do not assume every platform reads it. ZCode keeps Trellis-managed skills under `.zcode/skills/`.
 
 ## Decision Rules When Modifying Platform Files
 
diff --git a/packages/cli/src/templates/dsh/DSH.md b/packages/cli/src/templates/dsh/DSH.md
new file mode 100644
index 000000000..110f4339d
--- /dev/null
+++ b/packages/cli/src/templates/dsh/DSH.md
@@ -0,0 +1,56 @@
+# Trellis on DeepSeek Harness (dsh)
+
+dsh is a **class-2 pull-based** Trellis host: no session-start hook auto-injects
+workflow context, so the agent loads the Trellis skills on demand through its
+skill-loader tool.
+
+| Capability | Status |
+| --- | --- |
+| Skills (`.agents/skills/trellis-*/SKILL.md`) | Works — dsh discovers this shared root natively |
+| Entry skills (`.dsh/skills/trellis-*/SKILL.md`) | Works — dsh's own project skill root (highest rank) |
+| Context hooks | None — pull-based: skills read `.trellis/` files directly |
+| Sub-agents | None shipped — implement/check/research run inline via the workflow skills |
+
+## Quick start
+
+```bash
+trellis init --dsh -u your-name
+dsh web        # or: dsh --profile headless "start a Trellis task for ..."
+```
+
+In dsh:
+
+1. Open a session in the project root and describe the work in natural
+   language. For a new task the agent should load the `trellis-start` skill,
+   which reads the current task state from `.trellis/` and routes to
+   `trellis-brainstorm` (unclear requirements), `trellis-before-dev` (about to
+   write code), `trellis-check` (done coding), or `trellis-update-spec`
+   (learned something worth capturing).
+2. Entry skills are `trellis-start` / `trellis-continue` / `trellis-finish-work`
+   in `.dsh/skills/`. You can also ask for them by name at any time.
+3. Type `/trellis:finish-work` is a slash-command convention from other hosts —
+   dsh has no slash palette, so say "finish the trellis task" instead, and the
+   agent loads `trellis-finish-work`.
+
+## File map
+
+- `.agents/skills/` — auto-triggered workflow skills (`trellis-before-dev`,
+  `trellis-brainstorm`, `trellis-check`, `trellis-break-loop`,
+  `trellis-update-spec`) plus the bundled `trellis-meta` /
+  `trellis-spec-bootstrap` / `trellis-session-insight` skills. Byte-identical
+  to Codex / Gemini CLI / Pi / Kimi writes into the same shared root.
+- `.dsh/skills/` — dsh-private entry skills (`trellis-start` /
+  `trellis-continue` / `trellis-finish-work`).
+- `.trellis/` — specs, tasks, workspace memory, and the shared scripts the
+  skills invoke (`get_context.py`, `task.py`, ...).
+
+## Notes
+
+- Skill scripts pass `--platform dsh` to `get_context.py`; the value is used
+  as a platform-scoped context key.
+- The shipped `minimal` agent preset composes only `bash` +
+  `str_replace_editor`; the default presets include `web_search` and the
+  filesystem/terminal tools the skills assume.
+- dsh has no project-level sub-agent definition surface, so Trellis ships no
+  `trellis-implement` / `trellis-check` / `trellis-research` agent prompts
+  here — the workflow skills run those phases inline in the main session.
diff --git a/packages/cli/src/templates/dsh/index.ts b/packages/cli/src/templates/dsh/index.ts
new file mode 100644
index 000000000..2d5f216df
--- /dev/null
+++ b/packages/cli/src/templates/dsh/index.ts
@@ -0,0 +1,27 @@
+/**
+ * DeepSeek Harness (dsh) template module.
+ *
+ * dsh is a class-2 pull-based, skills-only platform:
+ * - Workflow + bundled skills go to the shared `.agents/skills/` root via
+ *   the neutral resolver (byte-identical to Codex/Gemini/Pi/Kimi writes).
+ * - User-invocable entry points (`trellis-start` / `trellis-continue` /
+ *   `trellis-finish-work`, loaded by the dsh agent through its skill-loader
+ *   tool) live under `.dsh/skills/<name>/SKILL.md` — dsh's own highest-rank
+ *   project skill root.
+ * - Operator guide `.dsh/DSH.md`.
+ *
+ * dsh has no shipped session-start hook, so `trellis-start` is kept as a
+ * user-invocable skill. dsh ships no project-level sub-agent definition
+ * surface, so no trellis-implement / trellis-check / trellis-research agent
+ * prompts are written; implement/check/research run inline through the
+ * workflow skills.
+ */
+
+import { createTemplateReader } from "../template-utils.js";
+
+const { readTemplate } = createTemplateReader(import.meta.url);
+
+/** Operator guide copied to `.dsh/DSH.md`. */
+export function getDshGuide(): string {
+  return readTemplate("DSH.md");
+}
diff --git a/packages/cli/src/templates/trellis/scripts/common/active_task.py b/packages/cli/src/templates/trellis/scripts/common/active_task.py
index c3caac0db..97a7784a6 100644
--- a/packages/cli/src/templates/trellis/scripts/common/active_task.py
+++ b/packages/cli/src/templates/trellis/scripts/common/active_task.py
@@ -55,6 +55,7 @@
     "kimi",
     "zcode",
     "snow",
+    "dsh",
 }
 
 # Every name below records how it was checked. Do NOT add a name by analogy
@@ -64,6 +65,15 @@
 # only "evidence" behind them. A platform with no verified name belongs in no
 # table; it resolves through TRELLIS_CONTEXT_ID or its hook/plugin bridge.
 _ENV_SESSION_KEYS: tuple[tuple[str, tuple[str, ...]], ...] = (
+    # REAL (reported 2026-08-13 against DSH 0.1.0-rc.6 by @SajoLuo, from a live
+    # run: DSH exports DSH_SESSION_ID plus DSH_SHELL=1 into its managed shell).
+    # MUST STAY FIRST. A DSH session can inherit an outer host's identity — a
+    # DSH launched from Codex still carries CODEX_THREAD_ID — and the untargeted
+    # lookup below walks this table in order, so any earlier entry would claim
+    # the session and write a foreign `codex_<thread>` pointer for DSH work.
+    # DSH_SESSION_ID is the only name here no other vendor sets, so first place
+    # is safe: it cannot mis-claim a non-DSH session.
+    ("dsh", ("DSH_SESSION_ID",)),
     # REAL, undocumented (verified 2026-08-05 in a live Claude Code 2.1.221 bash
     # child; absent from code.claude.com/docs/en/env-vars). CLAUDE_SESSION_ID
     # was removed here — verified absent from that same live environment.
diff --git a/packages/cli/src/templates/trellis/workflow.md b/packages/cli/src/templates/trellis/workflow.md
index bf3d1c136..158142e16 100644
--- a/packages/cli/src/templates/trellis/workflow.md
+++ b/packages/cli/src/templates/trellis/workflow.md
@@ -280,13 +280,13 @@ When a user request matches one of these intents inside an active task, route fi
 
 [/Claude Code, Cursor, OpenCode, codex-sub-agent, Kiro, Gemini, Qoder, CodeBuddy, Copilot, Droid, Pi, Oh My Pi, ZCode, Snow, Reasonix, Trae, Grok, Kimi Code]
 
-[codex-inline, Kilo, Antigravity, Devin]
+[codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 - Planning or unclear requirements -> `trellis-brainstorm`.
 - Before editing -> `trellis-before-dev`; after editing -> `trellis-check`.
 - Repeated debugging -> `trellis-break-loop`; spec updates -> `trellis-update-spec`.
 
-[/codex-inline, Kilo, Antigravity, Devin]
+[/codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 ### Guardrails
 
@@ -363,11 +363,11 @@ Spawn the research sub-agent:
 
 [/Claude Code, Cursor, OpenCode, codex-sub-agent, Kiro, Gemini, Qoder, CodeBuddy, Copilot, Droid, Pi, Oh My Pi, ZCode, Snow, Reasonix, Trae, Grok, Kimi Code]
 
-[codex-inline, Kilo, Antigravity, Devin]
+[codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 Do the research in the main session directly and write findings into `{TASK_DIR}/research/`. `codex-inline` is the explicit mode that keeps work in the main session.
 
-[/codex-inline, Kilo, Antigravity, Devin]
+[/codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 **Research artifact conventions**:
 - One file per research topic (e.g. `research/auth-library-comparison.md`)
@@ -427,11 +427,11 @@ Skip this step only when both files already have real curated entries.
 
 [/Claude Code, Cursor, OpenCode, codex-sub-agent, Kiro, Gemini, Qoder, CodeBuddy, Copilot, Droid, Pi, Oh My Pi, ZCode, Snow, Reasonix, Trae, Grok, Kimi Code]
 
-[codex-inline, Kilo, Antigravity, Devin]
+[codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 Skip this step. Context is loaded directly by the `trellis-before-dev` skill in Phase 2.
 
-[/codex-inline, Kilo, Antigravity, Devin]
+[/codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 #### 1.4 Activate task `[required · once]`
 
@@ -515,7 +515,7 @@ The platform prelude auto-handles the context load requirement:
 
 [/Kiro]
 
-[codex-inline, Kilo, Antigravity, Devin]
+[codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 1. Load the `trellis-before-dev` skill to read project guidelines
 2. Read `{TASK_DIR}/prd.md`, then `design.md` if present, then `implement.md` if present
@@ -523,7 +523,7 @@ The platform prelude auto-handles the context load requirement:
 4. Implement the code per reviewed artifacts
 5. Run project lint and type-check
 
-[/codex-inline, Kilo, Antigravity, Devin]
+[/codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 #### 2.2 Quality check `[required · repeatable]`
 
@@ -543,7 +543,7 @@ The check agent's job:
 
 [/Claude Code, Cursor, OpenCode, codex-sub-agent, Kiro, Gemini, Qoder, CodeBuddy, Copilot, Droid, Pi, Oh My Pi, ZCode, Snow, Reasonix, Trae, Grok, Kimi Code]
 
-[codex-inline, Kilo, Antigravity, Devin]
+[codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 Load the `trellis-check` skill and verify the code per its guidance:
 - Spec compliance
@@ -552,7 +552,7 @@ Load the `trellis-check` skill and verify the code per its guidance:
 
 If issues are found → fix → re-check, until green.
 
-[/codex-inline, Kilo, Antigravity, Devin]
+[/codex-inline, Kilo, Antigravity, Devin, DeepSeek Harness]
 
 **Final pass (before Phase 3.4 commit)**: the last 2.2 of a task must run full-scope, not just on the latest implement chunk. List all affected packages with `python3 ./.trellis/scripts/get_context.py --mode packages`, then load each package's spec index Quality Check section. This catches cross-layer / multi-package issues a mid-iteration local 2.2 cannot.
 
diff --git a/packages/cli/src/types/ai-tools.ts b/packages/cli/src/types/ai-tools.ts
index ee32e26a7..29fb87ce2 100644
--- a/packages/cli/src/types/ai-tools.ts
+++ b/packages/cli/src/types/ai-tools.ts
@@ -21,6 +21,7 @@ export type AITool =
   | "codebuddy"
   | "copilot"
   | "droid"
+  | "dsh"
   | "pi"
   | "reasonix"
   | "zcode"
@@ -48,6 +49,7 @@ export type TemplateDir =
   | "codebuddy"
   | "copilot"
   | "droid"
+  | "dsh"
   | "pi"
   | "reasonix"
   | "zcode"
@@ -75,6 +77,7 @@ export type CliFlag =
   | "codebuddy"
   | "copilot"
   | "droid"
+  | "dsh"
   | "pi"
   | "reasonix"
   | "zcode"
@@ -96,7 +99,8 @@ export interface TemplateContext {
     | "$"
     | "/"
     | "/skill trellis-"
-    | "/skill:trellis-";
+    | "/skill:trellis-"
+    | "trellis-";
   /** Description of AI executor actions shown in role tables */
   executorAI:
     | "Bash scripts or Task calls"
@@ -391,6 +395,31 @@ export const AI_TOOLS: Record<AITool, AIToolConfig> = {
       cliFlag: "droid",
     },
   },
+  dsh: {
+    // DeepSeek Harness (dsh) is a skills-first pull-based host: it reads
+    // `.agents/skills/` (agentskills.io, rank-200 project root) and its own
+    // `.dsh/skills/` (rank-100 project root) natively and the agent loads
+    // skills by name through its skill-loader tool. No session-start hook
+    // ships in the default web/headless profiles, so `hasHooks: false` and
+    // `trellis-start` stays as a user-invocable skill. Entry skills reference
+    // other skills by bare name (`trellis-<name>`), hence `cmdRefPrefix:
+    // "trellis-"`.
+    name: "DeepSeek Harness (dsh)",
+    templateDirs: ["common", "dsh"],
+    configDir: ".dsh",
+    supportsAgentSkills: true,
+    cliFlag: "dsh",
+    defaultChecked: false,
+    hasPythonHooks: false,
+    templateContext: {
+      cmdRefPrefix: "trellis-",
+      executorAI: "Bash scripts or tool calls",
+      userActionLabel: "Skills",
+      agentCapable: true,
+      hasHooks: false,
+      cliFlag: "dsh",
+    },
+  },
   pi: {
     // Pi also writes .agents/skills/, which is read by Cursor, Gemini CLI,
     // GitHub Copilot, Amp, and Kimi Code. Keep that detail here rather than
diff --git a/packages/cli/test/commands/update.integration.test.ts b/packages/cli/test/commands/update.integration.test.ts
index b01470f55..fc2c73e33 100644
--- a/packages/cli/test/commands/update.integration.test.ts
+++ b/packages/cli/test/commands/update.integration.test.ts
@@ -813,8 +813,11 @@ describe("update() integration", () => {
     // auto-updated to the current packaged template.
     expect(readProjectFile(PATHS.WORKFLOW_GUIDE_FILE)).toBe(expectedWorkflow);
     expect(readProjectFile(MANAGED_FILE)).toBe(expectedGetContext);
+    // Prefix, not the whole marker: the inline block gains members as
+    // sub-agent-less platforms are added, and this assertion is about the
+    // block surviving the update, not about who is currently in it.
     expect(readProjectFile(PATHS.WORKFLOW_GUIDE_FILE)).toContain(
-      "[codex-inline, Kilo, Antigravity, Devin]",
+      "[codex-inline, Kilo, Antigravity, Devin",
     );
     expect(readProjectFile(PATHS.WORKFLOW_GUIDE_FILE)).not.toContain("[Codex]");
 
@@ -1507,7 +1510,7 @@ describe("update() integration", () => {
     expect(updated).toContain(
       "[/Claude Code, Cursor, OpenCode, codex-sub-agent, CodeBuddy, Droid, Pi, ZCode, Snow, Oh My Pi]",
     );
-    expect(updated).toContain("[codex-inline, Kilo, Antigravity, Devin]");
+    expect(updated).toContain("[codex-inline, Kilo, Antigravity, Devin");
     expect(updated).not.toContain("[Codex]");
     expect(updated).not.toContain("[Kilo, Antigravity, Windsurf]");
     expect(updated).not.toContain("legacy body");
diff --git a/packages/cli/test/configurators/index.test.ts b/packages/cli/test/configurators/index.test.ts
index 4b531df7f..268d7d2a2 100644
--- a/packages/cli/test/configurators/index.test.ts
+++ b/packages/cli/test/configurators/index.test.ts
@@ -77,6 +77,7 @@ describe("isManagedPath", () => {
     expect(isManagedPath(".github/hooks/trellis.json")).toBe(true);
     expect(isManagedPath(".pi/extensions/trellis/index.ts")).toBe(true);
     expect(isManagedPath(".pi/prompts/trellis-continue.md")).toBe(true);
+    expect(isManagedPath(".dsh/skills/trellis-start/SKILL.md")).toBe(true);
   });
 
   // Positive: exact match (startsWith(d + "/") = false, === d = true)
@@ -91,6 +92,7 @@ describe("isManagedPath", () => {
     expect(isManagedPath(".devin/workflows")).toBe(true);
     expect(isManagedPath(".github/prompts")).toBe(true);
     expect(isManagedPath(".github/hooks")).toBe(true);
+    expect(isManagedPath(".dsh")).toBe(true);
     expect(isManagedPath(".trellis")).toBe(true);
   });
 
@@ -114,6 +116,7 @@ describe("isManagedPath", () => {
     expect(isManagedPath(".github/prompts-backup")).toBe(false);
     expect(isManagedPath(".github/copilot-backup")).toBe(false);
     expect(isManagedPath(".github/hooks-backup")).toBe(false);
+    expect(isManagedPath(".dsh-backup")).toBe(false);
   });
 
   // Boundary: empty string
diff --git a/packages/cli/test/configurators/platforms.test.ts b/packages/cli/test/configurators/platforms.test.ts
index b3db51edd..e79f8bfae 100644
--- a/packages/cli/test/configurators/platforms.test.ts
+++ b/packages/cli/test/configurators/platforms.test.ts
@@ -1030,6 +1030,60 @@ describe("configurePlatform", () => {
     );
   });
 
+  it("configurePlatform('dsh') writes shared + dsh-private skills and the operator guide", async () => {
+    await configurePlatform("dsh", tmpDir);
+
+    // hasHooks=false → trellis-start stays as a user-invocable dsh skill
+    expect(
+      fs.existsSync(
+        path.join(tmpDir, ".dsh", "skills", "trellis-start", "SKILL.md"),
+      ),
+    ).toBe(true);
+    expect(
+      fs.existsSync(
+        path.join(tmpDir, ".dsh", "skills", "trellis-continue", "SKILL.md"),
+      ),
+    ).toBe(true);
+    expect(
+      fs.existsSync(
+        path.join(tmpDir, ".dsh", "skills", "trellis-finish-work", "SKILL.md"),
+      ),
+    ).toBe(true);
+    expect(
+      fs.readFileSync(
+        path.join(tmpDir, ".dsh", "skills", "trellis-start", "SKILL.md"),
+        "utf-8",
+      ),
+    ).toContain("--platform dsh");
+
+    // Shared workflow skills land in .agents/skills/, entry skills stay private
+    expect(
+      fs.existsSync(
+        path.join(tmpDir, ".agents", "skills", "trellis-check", "SKILL.md"),
+      ),
+    ).toBe(true);
+    expect(
+      fs.existsSync(
+        path.join(tmpDir, ".agents", "skills", "trellis-start", "SKILL.md"),
+      ),
+    ).toBe(false);
+
+    expect(
+      fs.readFileSync(path.join(tmpDir, ".dsh", "DSH.md"), "utf-8"),
+    ).toContain("class-2");
+
+    // No hooks/settings — dsh ships no project-level hook surface
+    expect(fs.existsSync(path.join(tmpDir, ".dsh", "settings.json"))).toBe(
+      false,
+    );
+    expect(fs.existsSync(path.join(tmpDir, ".dsh", "hooks"))).toBe(false);
+    expect(fs.existsSync(path.join(tmpDir, ".dsh", "agents"))).toBe(false);
+
+    expect(AI_TOOLS.dsh.templateContext.hasHooks).toBe(false);
+    expect(AI_TOOLS.dsh.hasPythonHooks).toBe(false);
+    expect(AI_TOOLS.dsh.supportsAgentSkills).toBe(true);
+  });
+
   it("configurePlatform('zcode') writes only .zcode-owned skills", async () => {
     await configurePlatform("zcode", tmpDir);
 
diff --git a/packages/cli/test/regression.test.ts b/packages/cli/test/regression.test.ts
index 2e8dad033..749f11717 100644
--- a/packages/cli/test/regression.test.ts
+++ b/packages/cli/test/regression.test.ts
@@ -3022,6 +3022,16 @@ print(json.dumps({
           { CLAUDE_CODE_SESSION_ID: "real", CLAUDE_SESSION_ID: "legacy" },
           "zcode",
         ],
+        ["dsh", { DSH_SESSION_ID: "probe" }, "dsh"],
+        // DSH ships no hook, so the shell path resolves with no platform hint
+        // and walks the whole table. A DSH launched from Codex inherits
+        // CODEX_THREAD_ID; without DSH sitting first this returned a foreign
+        // `codex_outer` pointer (reported by @SajoLuo against DSH 0.1.0-rc.6).
+        [
+          "dsh-inherits-codex",
+          { DSH_SESSION_ID: "own", CODEX_THREAD_ID: "outer" },
+          null,
+        ],
       ],
     );
 
@@ -3043,6 +3053,8 @@ print(json.dumps({
       "zcode-real": "claude_probe",
       "zcode-legacy": "claude_probe",
       "zcode-prefers-real": "claude_real",
+      dsh: "dsh_probe",
+      "dsh-inherits-codex": "dsh_own",
     });
   });
 
diff --git a/packages/cli/test/templates/dsh.test.ts b/packages/cli/test/templates/dsh.test.ts
new file mode 100644
index 000000000..4f2e14098
--- /dev/null
+++ b/packages/cli/test/templates/dsh.test.ts
@@ -0,0 +1,62 @@
+import { describe, expect, it } from "vitest";
+import { collectDshTemplates } from "../../src/configurators/dsh.js";
+import { collectPiTemplates } from "../../src/configurators/pi.js";
+
+describe("dsh collectDshTemplates", () => {
+  it("writes entry skills under .dsh/skills/ (dsh-native project root)", () => {
+    const files = collectDshTemplates();
+
+    // User-invocable entry points (no slash palette → delivered as skills)
+    expect(files.has(".dsh/skills/trellis-start/SKILL.md")).toBe(true);
+    expect(files.has(".dsh/skills/trellis-continue/SKILL.md")).toBe(true);
+    expect(files.has(".dsh/skills/trellis-finish-work/SKILL.md")).toBe(true);
+
+    // Platform-resolved placeholders: get_context.py calls carry --platform dsh
+    const start = files.get(".dsh/skills/trellis-start/SKILL.md");
+    expect(start).toContain("--platform dsh");
+    expect(start).toContain("name: trellis-start");
+  });
+
+  it("renders CMD_REF as bare trellis-<name> skill references in entry skills", () => {
+    const files = collectDshTemplates();
+    const finish = files.get(".dsh/skills/trellis-finish-work/SKILL.md");
+    // `{{CMD_REF:finish-work}}` → `` `trellis-finish-work` `` (dsh loads
+    // skills by name through its skill-loader tool)
+    expect(finish).toContain("`trellis-finish-work`");
+  });
+
+  it("writes workflow + bundled skills to the shared .agents/skills/ root only", () => {
+    const files = collectDshTemplates();
+    expect(files.has(".agents/skills/trellis-check/SKILL.md")).toBe(true);
+    expect(files.has(".agents/skills/trellis-before-dev/SKILL.md")).toBe(true);
+    expect(files.has(".agents/skills/trellis-meta/SKILL.md")).toBe(true);
+    // Command-as-skill files stay dsh-private (Codex owns the shared
+    // trellis-start/continue/finish-work fallback copies).
+    expect(files.has(".agents/skills/trellis-start/SKILL.md")).toBe(false);
+    expect(files.has(".agents/skills/trellis-finish-work/SKILL.md")).toBe(
+      false,
+    );
+  });
+
+  it("renders .agents/skills/ files byte-identically to Pi's shared writes", () => {
+    const dshFiles = collectDshTemplates();
+    const piFiles = collectPiTemplates();
+    for (const [key, content] of dshFiles) {
+      if (!key.startsWith(".agents/skills/")) continue;
+      expect(
+        piFiles.get(key),
+        `${key} must be byte-identical to Pi's shared-skill write`,
+      ).toBe(content);
+    }
+  });
+
+  it("ships an operator guide and no hooks/settings files", () => {
+    const files = collectDshTemplates();
+    expect(files.get(".dsh/DSH.md")).toBeDefined();
+    for (const key of files.keys()) {
+      expect(key.startsWith(".dsh/hooks")).toBe(false);
+      expect(key).not.toBe(".dsh/settings.json");
+      expect(key).not.toBe(".dsh/config.toml");
+    }
+  });
+});