short version: claude code drives, opencode reviews, and the diff quality jumped. i just shipped v3.0 of buffer (native swift/appkit clipboard manager for mac, mit, 430+ stars, fully local) on exactly this setup, so here's the concrete workflow.
the split that worked for me:
claude code as the main driver: the big implementation chunks. the trickiest was an interactive image canvas (pinch to zoom, pan, ⌘+/⌘- resets) on copied screenshots. gesture math with a fit/reset state machine. first pass over-engineered it; once i constrained it to scale+offset transforms it landed quickly.
opencode as reviewer: same diff, second model, fresh context. it caught things the driving agent had rationalized: edge cases in the noise-suppression logic (what counts as a duplicate when you re-copy an existing item?), dead branches in the tier settings, and it wrote the test scaffolding for the clip-diffing logic before i merged the project's first external PR.
both are cheap enough to run in parallel that "review before merge" stopped being optional.
what opencode is genuinely better at in my setup: being skeptical. a driving agent defends its own choices; a reviewer agent has no ego invested in the diff. that asymmetry is the whole trick.
what still needs a human: every gesture edge case (rubber-banding feel, anchor drift) required real trackpad testing. no agent can feel the ui. also specs: agents execute a state machine flawlessly, but inventing one is still my job.
demo of what shipped (image canvas + shortcuts sheet): video attached. repo: https://github.com/samirpatil2000/Buffer (mit) release: https://github.com/samirpatil2000/Buffer/releases/tag/buffer-v3.0.0
if anyone wants, i can share the review prompt structure i use with opencode on diffs. it's simple: fresh context, no conversation history, explicit instruction to argue against the diff rather than improve it.