Next harness: GitHub Copilot, deferred
Workstream W9 of “More than one harness” changes from opencode and pi to the Copilot CLI through ACP. It will be built once someone asks for it.
opencode and pi dropped
- They open many providers, but Claude subscriptions are blocked in third-party harnesses (since Jan 2026), and ChatGPT already runs through Codex.
- What is left (open-weight models, local models) asks a lot of weaker models for Obeya's long autonomous work and demos.
- The two overlap almost completely.
Copilot CLI via ACP deferred
- Reaches developers whose company allows only Copilot. Obeya can't serve them today.
- Models as the plan and the admin allow: Claude, GPT and Codex models, Gemini.
- ACP is an open protocol (opencode and Gemini CLI speak it too), so the same runtime opens the door to more harnesses.
| Why deferred | What it means for Obeya |
|---|---|
| Copilot CLI is off in organizations until an admin enables it. Models need enabling too. | Many Copilot-only users couldn't use it without asking IT first. |
| Usage-based billing since June 2026: Business includes $19 of credit a month. | A few long, parallel cards on a strong model use that up. |
| No source counts Copilot-only developers. In JetBrains' 2026 survey, 21% use Copilot at work and 39% use Claude Code, and developers use 2.3 tools on average. | Demand isn't proven. We build when a real user asks. |
| Not yet checked: whether a session can resume after a restart, and whether usage can be read for the usage bar. | The first two things to check before building. |
Sources: ACP in Copilot CLI · Copilot CLI GA · CLI policy · Usage-based billing · Subscriber numbers · JetBrains survey · Claude subscriptions in third-party harnesses