Aider vs OpenCode

When to pick Aider

• You want git to be the review surface: Aider commits every AI edit on its own with a generated message, so git log and git revert are the whole workflow — no separate session UI to learn.
• You want the smallest possible tool: one pip install, one terminal, no account, no gateway, no vendor balance to top up, and no optional paid tier tempting you upward.
• You already run a local model through Ollama and want genuinely zero end-to-end cost — Aider’s model-agnostic design means the tool never routes through a vendor you have to trust or pay.

When to pick OpenCode

• You want more than a terminal: the desktop app, IDE extension, and web interface cover the same agent, and multi-session support lets several agents work one project in parallel.
• You need predictable spend — Go is $5 for the first month then $10/month across 15 open models, with hard caps at $12 per 5 hours and $60 per month, versus Aider’s uncapped bring-your-own-key billing.
• You already pay for GitHub Copilot or ChatGPT Plus/Pro: OpenCode reuses that login instead of making you buy a second entitlement, and falls back to 75+ providers when you want something else.

Bottom line

These are the two strongest free terminal agents, and the split is minimalism versus surface area. Aider is the better choice if your workflow is already git-centric and you want a single CLI that adds nothing else — auto-commits make every AI change reviewable with tools you already use, and at $0 with your own key the tool never charges you anything. OpenCode is the better default for everyone else: four interfaces instead of one, parallel sessions, an actual API, and a $10/month plan that turns unpredictable token spend into a fixed line item. The maintenance gap is the tiebreaker worth weighing — OpenCode ships releases monthly and takes commits daily, while Aider’s last published release was five months ago, which matters when model APIs change underneath a tool that depends on all of them.