Runtime Modes

DeepSeek Harness Runtime Modes

DeepSeek Harness ships four runtime modes: Standard, Code (PTC), Minimal, and Creator. From daily coding to model benchmarking, from multi-step orchestration to plugin experiments — every mode is composed of plugins and can be selected freely when starting a new session.

Four Runtime Modes

STANDARD MODE

Standard Mode

Full coding agent

Includes the full toolset: file editing, shell, file and web search, skills, planning, goals, subagents, and workflows. The default choice for day-to-day coding tasks.

File editingShellFile & web searchSkillsPlanning & goalsSubagentsWorkflows

Use case: Daily coding: read the repo, edit code, run tests, commit changes.

CODE MODE

Code Mode (PTC)

Orchestrate tools in one TypeScript program

All Standard mode capabilities, with tools exposed through the Code Mode SDK so the model can combine multi-step operations in one TypeScript program. Complex tasks become composable, reusable programs instead of linear tool-call chains.

All Standard toolsCode Mode SDKTypeScript orchestrationMulti-step in one

Use case: Complex orchestration: bulk refactors, cross-file analysis, multi-step tasks needing loops and conditionals.

MINIMAL MODE

Minimal Mode

Two-tool benchmarking environment

A two-tool coding agent with persistent bash and str_replace_editor, for benchmarking models in a minimal environment. No distracting tools — a purer evaluation of model capability.

Persistent Bashstr_replace_editor

Use case: Model evaluation: fair benchmarks in a minimal environment.

CREATOR MODE

Creator Mode

Build custom agent presets

Built for creating custom agent presets: all Standard mode capabilities plus runtime inspection, plugin experiments, and preset-authoring guidance. Test Cordis plugins in memory and combine them into new runtime modes.

All Standard toolsRuntime inspectionPlugin experimentsPreset guidance

Use case: Harness customization: inspect the runtime, experiment with plugins, author your own agent presets.

Mode Comparison

Compare the four runtime modes by toolset and use case:

ModeToolsetOrchestrationUse case
StandardFull toolsetWorkflowsDaily coding
Code (PTC)Standard + Code Mode SDKTypeScript programComplex multi-step tasks
MinimalBash + file editorLinear tool callsModel benchmarking
CreatorStandard + runtime inspectionPlugin experimentsCustom agent presets

The four modes are themselves composed of plugins: every capability is a plugin, and every mode is a composition of plugins.

How to Switch Modes

When creating a new session in the Web UI, expand the mode selector to pick a runtime mode. Presets composed in Creator mode also appear in the selector for later sessions.

# Launch the Web UI and pick a mode for a new session
npx @deepseek-ai/dsh web

# New session → expand the mode selector
# ┌──────────────┐
# │ Standard     │  ← full-featured coding agent
# │ Code (PTC)   │  ← orchestrate tools in TypeScript
# │ Minimal      │  ← two-tool benchmarking
# │ Creator      │  ← inspect runtime, test plugins
# └──────────────┘

Learn More

FAQ

What runtime modes does DeepSeek Harness offer?

Four: Standard mode (full toolset), Code/PTC mode (Code Mode SDK orchestration), Minimal mode (two-tool benchmarking), and Creator mode (building custom presets).

What's the difference between Code mode and Standard mode?

Code mode has all Standard mode capabilities, but tools are exposed through the Code Mode SDK — the model writes one TypeScript program combining multi-round tool calls, ideal for complex multi-step orchestration.

When should I use Minimal mode?

Minimal mode keeps only persistent bash and str_replace_editor — ideal for benchmarking models in a minimal environment with a purer evaluation.

How do I experiment with plugins in Creator mode?

Creator mode provides runtime inspection and plugin experiments: load Cordis plugins in memory, observe their behavior, and save the composition as a new preset.

Join the DSH plugin ecosystem

DeepSeek Harness remains in developer preview and is still being tested by developers building agent harnesses. Its core plugins and APIs will continue to evolve. We look forward to exploring the limits of intelligence with developers worldwide using open-source infrastructure that is reusable and composable.