OpenCode 2.0 changed four things the daemon depends on. Two fail loudly —
`--dir` and `--variant` both exit 1 on an unrecognized flag, which is why every
task on a 2.x runtime died in ~130ms with empty output (GH #8586). Two are
silent: MCP config had no working channel left, and `opencode run` became a thin
client in front of a resident service, so signalling the client's process group
no longer stopped the run.
- `--dir` is dropped on 2.x; the workdir comes from cmd.Dir + PWD.
- The thinking level folds into the model string as `provider/model#variant`.
- Cancellation calls POST /api/session/<id>/interrupt in front of the existing
SIGTERM→SIGKILL, which is the only thing that stops a 2.x run.
- Runs carrying Multica-managed MCP servers are refused with an error naming
every source, rather than started without them: 2.x accepts MCP only through a
file in the task workdir, where the agent's own commits would capture the
credentials. Restoring MCP is tracked separately.
The 1.x path is unchanged, pinned by argv and MCP regression tests. Verified
against @opencode/cli 2.0.10 and opencode-ai 1.18.31 on macOS/arm64; Windows
cancellation is not yet verified end to end.
