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dsh-epoch-reanchor

dsh-epoch-reanchor is an experimental DeepSeek Harness (DSH) plugin for testing an unproven observation: after context compaction, do the summary and retained trajectory affect whether the model re-enters a chain of thought with visible We ... and Let's ... traits (called “We/Let's traits” below)?

At the compaction boundary, the plugin ends the old model-visible trajectory, recasts the required work state as an ordinary user handoff, and starts a new epoch with the official Minimal system and two-tool surface. After the epoch makes its first real tool call, the next step exposes the complete Standard tool catalog. This minimizes prior-trajectory conditioning without restricting the whole task to two tools.

Apart from rebuilding model-visible history, the plugin tries to preserve the official repository's verifiable environment traits throughout the task: the Minimal system, platform shell/editor bootstrap, Standard tool surface after the first tool call, and the official compaction pressure, tail, and cache-replay behavior. It does not claim exact semantics that the host platform cannot provide.

Local children that do not inherit a parent transcript use the same epoch rules. When a child has a custom persona, the plugin keeps its system Minimal and deterministically places that persona at the end of the ordinary user task/handoff. Model-hidden agent state restores it after every compaction.

Session identity, workspace, raw events, and UI history remain continuous. Only the model-visible message history is rebuilt. The official AgentLoop is not replaced.

> [!IMPORTANT] > We/Let's phrases are observable textual traits, not a description of the model's complete internal mechanism. They do not by themselves prove reasoning quality or proximity to an RL post-training distribution. This project is intended for A/B testing, and no large-scale evaluation currently proves that either mode is generally better.

How it works

Epoch N
  Minimal system + platform shell/editor
  first tool call → full Standard tools
  append-only trajectory
        │
        │ compaction
        ▼
  older head → handoff summary
  recent tail → numbered records
        │
        ▼
  replace the complete model-visible surface
        │
        ▼
Epoch N+1
  Minimal system + platform shell/editor
  one ordinary user handoff
  first tool call → full Standard tools

The plugin keeps the official pressure threshold, tail selection, token meter, tool-pair boundary, cache-replay summary, and failure rollback. It changes only the final replacement so the new epoch does not inherit the old assistant/tool-role trajectory.

The new epoch starts with:

System: You are a helpful software engineer assistant.
Tools:  Linux/macOS: bash + str_replace_editor
        Windows:     pwsh + str_replace_editor (default)
                     bash + str_replace_editor (optional Git Bash)
User:   earlier task state + recent interaction records

After the first durable tool/call, the next request exposes the official Standard preset's tool catalog. A successful compaction closes the gate again. Automatic AGENTS digests and the skill catalog are suppressed on the bootstrap request and restored after promotion; <compacted-summary>, internal compaction details, and runtime snapshots are never injected.

Subagent boundary

• A fresh local child (normally spawn) starts with the Minimal system and platform tool pair, then promotes only to tools allowed by its toolFilter.
• A custom persona becomes a lower-priority user-role task condition instead of a system instruction. This is an intentional experimental variable, not equivalent to official persona semantics.
• If toolFilter removes either required bootstrap tool, the experimental child fails loudly rather than silently producing an unaligned trajectory.
• Seeded fork children and external Codex, Claude Code, or ACP providers retain official behavior and are outside the fresh-epoch comparison.

A/B presets

The two presets are identical except for includeTailReasoning.

The recent tail is still selected by the official token-budget algorithm. User messages, visible assistant text, tool calls/results, errors, and images keep their order and are mechanically converted into ordinary numbered records.

Install

Requirements:

• Node.js ^22.19.0 or >=24;
• DeepSeek Harness 0.1.0-rc.6.

Install into the web profile:

dsh plugin --profile web add github:whycantiusemyname/dsh-epoch-reanchor
dsh plugin --profile web exec dsh-epoch-reanchor install-presets

Replace web with another profile name when needed. The package must be installed into every profile that will use the presets; the preset directories themselves live under the shared $DSH_HOME/.agent-presets root.

pnpm may report peer-dependency warnings for official packages supplied through the DSH installation fallback. The loader path has been smoke-tested.

To upgrade an existing installation, remove the copied presets before updating and reinstalling them:

dsh plugin --profile web exec dsh-epoch-reanchor remove-presets
dsh plugin --profile web add github:whycantiusemyname/dsh-epoch-reanchor
dsh plugin --profile web exec dsh-epoch-reanchor install-presets

Use

1. Fully restart DSH. 2. Create a blank Session. 3. Select one Epoch Re-anchor preset. 4. Keep that Session on the same preset.

Do not switch an active Session between presets.

dsh plugin --profile web exec dsh-epoch-reanchor status
dsh plugin --profile web exec dsh-epoch-reanchor paths

Uninstall:

dsh plugin --profile web exec dsh-epoch-reanchor remove-presets
dsh plugin --profile web remove dsh-epoch-reanchor

Keep the package and presets while existing Sessions still need to resume.

KV cache

After the first tool call, history remains append-only and the full Standard tool schema stays stable for the rest of the epoch. The summary request reuses the old system, tools, and older-head prefix before appending a fixed compaction instruction.

Each epoch deliberately changes the prefix twice: the boundary switches to the Minimal pair, then the first tool call switches to the full Standard catalog. Both transitions limit direct reuse of the previous KV tail; the prefix can grow stably again until the next compaction. Actual cache hits, lifetime, and pricing are provider-controlled.

Platforms

• Linux/macOS: official persistent PTY Bash with str_replace_editor, providing the closest match to the official Minimal RL interface.
• Native Windows, default: follows the official DSH platform composition and uses pwsh with str_replace_editor. It is reliable, but its schema and execution semantics are not equivalent to Linux Bash.
• Native Windows, optional: set windowsShell to git-bash in the dsh-epoch-reanchor section of $DSH_HOME/settings.yaml. This exposes bash with str_replace_editor and retains the official persistent Bash tool's single command parameter shape, but starts a fresh Git Bash process for every call.

The equivalent $DSH_HOME/settings.yaml section is:

dsh-epoch-reanchor:
  windowsShell: git-bash
  gitBashPath: 'C:\Program Files\Git\bin\bash.exe'

gitBashPath defaults to bash and is resolved through PATH. These settings apply after a full DSH restart. Git Bash is only a syntax-compatibility experiment backend; it does not reproduce Linux persistent Bash cwd, environment, user-space, or process semantics. Use Linux, WSL2, or a Linux container when strict RL shell-interface control matters.

In DSH 0.1.0-rc.6, the Web Settings form exposes only namespaces on the official allowlist, so the third-party dsh-epoch-reanchor section must currently be edited in settings.yaml.

A/B guidance

Use a fresh Session for each mode and keep the model, reasoning effort, task, repository state, permissions, and compaction settings fixed. Compare post-compaction We/Let's traits, the first tool call, behavior after the full catalog opens, token/cache usage, and final task quality.

Verification

npm test
npm pack --dry-run

Tests also cover fresh-child Minimal systems, deferred persona restoration across epochs, independent tool gates, toolFilter failure, fork isolation, and single-variable preset parity.

Limitations

• The better tail-reasoning mode is not established.
• If the model never calls a tool, that epoch remains on the two-tool surface.
• Whether opening the full Standard catalog changes We/Let's traits requires testing.
• Role flattening does not remove semantic influence from retained text.
• A user-role persona may be followed less strongly than the official system persona.
• Forked and external providers are outside the fresh Subagent Epoch experiment.
• Native Windows pwsh mode is not Linux persistent Bash.
• Optional Git Bash mode starts a fresh process per call and is not Linux persistent Bash either.
• DSH is a developer preview; recheck APIs and preset composition after upgrades.

Sources

Official baseline: deepseek-ai/deepseek-harness, commit 47f943859bef60e4160492346772ded9b24f765a, especially the official Minimal/Standard presets, dsh-compaction-basic, the compaction service, and Session projection.

Community experiment reference: xiaobright/dsh-anchored-standard and its experimental presets studying model-visible system/tool composition, first-request trajectory, and the official Minimal interface.

This project is not a branch of that repository and contains no copied community code. See [NOTICE](./NOTICE) for official MIT attribution.

License

MIT