The practical answer
A harness is the surrounding software that lets a model use tools and continue a task. A workspace organises how you work with those agents. The terms overlap, so compare concrete behaviour rather than labels.
The model, the agent and the surrounding software
A model generates responses from the input it receives. In a coding workflow, those responses can include proposed file edits, tool calls or instructions. Something outside the model must decide which tools are available, execute permitted actions, return results, and keep the conversation moving.
People often call that surrounding machinery an agent harness. The term is used loosely: one person may mean the tool-execution loop, another may include permissions, context management and session storage. There is no need to resolve the label before assessing a tool. Ask what it actually runs and what decisions you can inspect.
A coding agent combines a model with that machinery to work on a programming task. A workspace helps you organise the agents, terminals, accounts and projects you use. A product can cover several of these roles.
Compare the responsibilities
| Part | Typical responsibility | Question to ask |
|---|---|---|
| Model | Generate responses and proposed actions | What provider and account will receive my input? |
| Harness | Run tools, return results and manage the task loop | What can it execute, and what needs permission? |
| Coding agent | Use that loop to inspect, edit and check code | Can I see the edits and verify the result? |
| Workspace | Organise sessions, projects and accounts | Which tool and working folder does each session use? |
These are practical distinctions, not a universal taxonomy. A command-line coding tool may contain its own harness and session manager. A desktop workspace may host that CLI without replacing its model or tool policies.
Why the harness matters in daily work
Consider an agent asked to fix a failing test. It needs to read relevant files, change code, run the test and see whether the failure is resolved. The surrounding software controls how those actions happen. A missing tool, an ambiguous permission prompt or lost session context can interrupt the task even when the model can reason about the code.
Useful questions include whether the tool can resume a conversation, how it handles a failed command, whether you can interrupt it, and what it does when an account is limited. Ask what is stored locally and what is sent to a provider. An attractive interface alone does not answer these questions.
Also separate observed status from interpretation. A running process is not proof that an agent is making progress. An unknown usage reading is not unlimited capacity. Good tools make these limits visible rather than supplying comforting guesses.
Where Towfu belongs
Towfu is a local Windows workspace around coding-agent tools, including Claude Code and Codex. It brings sessions into one window, separates provider profiles, shows available account usage, and supports Git worktrees for individual agents. Customers bring their own provider accounts.
For terminal sessions, Towfu hosts the underlying CLI in a real terminal. The CLI still talks to its provider. Towfu is not a new foundation model, and a Towfu subscription does not include the underlying model subscription. See the compatible tools and pricing on the product page.
The local workspace boundary matters. Towfu adds no telemetry, but using a cloud coding agent still involves that provider's service. Read Towfu's privacy policy and the terms of the providers you use when deciding which projects to open.
Choose using a task you can verify
Start with a small, reproducible task in a test repository. Check whether you can identify the active account, see the working folder, understand a permission prompt, review the diff and find the session afterwards. Then try one controlled interruption, such as closing and reopening the interface, and inspect what actually resumes.
Record observed behaviour rather than relying on a broad “autonomous” claim. If a new session reads a handoff note, that is different from resuming the original conversation. If two agents work in separate folders, they can still produce conflicting changes.
Once one session is reliable, try a two-agent review workflow. The Windows pairing guide and review checklist give you a starting point. Add more agents when you can explain what each one owns and how its result will be checked.