DeepSeek Harness: Build Plugins, Tools & AI Agents

This course contains the use of artificial intelligence.

DeepSeek Harness turns AI models into agents that can work inside real environments. In this practical, screen-based course, you will learn how the system works by building, breaking, inspecting, and repairing real projects.

The course begins with the core idea behind DeepSeek Harness: every capability is a plugin. You will explore the Web UI, install and run the harness, diagnose a broken project, and inspect complete agent trajectories. Instead of hiding failures, the lessons use them as evidence. You will see tool inputs, outputs, session records, model request options, edits, tests, and final proof directly on screen.

You will then build custom plugins, commands, services, tools, and local skills. You will learn how Cordis connects providers and consumers, how plugin layers can be mounted and removed cleanly, and how to package reusable release archives. You will also compare implementations that share the same service contract, so you can understand how modular agent systems stay flexible.

Safety and control are treated as engineering requirements. The course demonstrates permissions, one-time approvals, sandbox boundaries, secret protection, and policy guardrails. You will see both allowed and blocked behavior, inspect the recorded evidence, and verify that cleanup restores the expected state.

The workflow lessons cover Plan Mode, live checklists, context compaction, child-agent sessions, parallel agents, and structured multi-agent workflows. You will learn how to stop a long-running loop without damaging the project, continue one child agent while preserving its history, and organize multi-phase work around shared evidence and clear roles.

Finally, you will compare the official Web, headless, and Python SDK surfaces. This gives you a practical view of sessions, reuse, logs, configuration, and programmatic execution.

By the end of the course, you will be able to:

• Explain the DeepSeek Harness plugin architecture

• Diagnose projects with trajectories and session records

• Build plugins, services, commands, tools, and skills

• Apply permissions, approvals, sandboxes, and safety policies

• Run planning, context, and multi-agent workflows

• Package plugins and use Web, headless, and Python SDK interfaces

Every lesson is concise and focused on visible actions, real results, and verification. The course is taught in clear English and is designed for developers, AI engineers, and technical learners who want a grounded introduction to an open-source agent harness.

This is an independent educational course and is not affiliated with or endorsed by DeepSeek.