Build Your Own Agent Harness
Planned BeginnerIntermediateAdvanced
Get notified on YouTube Udemy certificate: coming soon
- Udemy
- Coming soon
- Lessons
- 16
- Planned length
- About 4 h 27 min
- Projects
- 1
- Practicals
- Planned: a hands-on practical and a Udemy assignment in every section, plus a capstone
What you will be able to do
- Draw the loop real coding agents use
- Write a working agent loop with one tool on a local model
- Add input checks, ask-before-acting and a sandbox folder
- Budget tokens with summaries and notes files
- Make the agent plan and delegate to a helper
- Guard, test and port your agent to an official SDK
Syllabus
AI Agents: Build an Agent From Scratch
- What an Agent Harness Really Is Draw the loop real coding agents use
- The Agent Loop in 50 Lines Write a working agent loop with one tool on a local model
- Tools and Permissions Add input checks, ask-before-acting and a sandbox folder
- Context: What the Agent Remembers Budget tokens with summaries and notes files
- Plans, To-Do Lists and Sub-Agents Make the agent plan and delegate to a helper
- Safety, Evals, and Rebuilding With an SDK Guard, test and port your agent to an official SDK
AI Agents: Agent Harness Engineering
- The Eight Parts of an Agent Harness Name the loop, tools, context, memory, permissions, sandbox, subagents and hooks in any agent product
- How Coding-Agent Harnesses Are Built (Claude Code, Codex) Compare coding-agent harness designs from their public docs
- Skills and Plugins: Package Know-How for Agents Write a skill an agent loads only when it needs it
- Hooks: Run Your Own Code Before and After Every Tool Call Block, log or fix tool calls with hooks
- Human Approvals: Permission Modes and Allow/Deny Rules Design an approval policy that is safe without nagging
- Context Engineering for Long Tasks: Compaction and Notes Keep a multi-hour task on track across context resets
- Sandboxing Agents: Containers, Files, Network, Secrets Run an agent with least privilege in a container
- Project: Build a Mini Coding-Agent Harness Ship a small harness that fixes a failing test in a sandbox
- Evaluate a Harness: Same Model, Different Harness Measure task success, pass^k and cost per solved task across harness changes
- Cost and Latency Budgets for Agents Set and enforce per-task cost and time budgets
Take before
Lesson list from the ADITEJUS curriculum. Planned lengths are estimates per lesson; Udemy shows the final length.