Don’t POST a command array to Foremerge 0.5.0 HTTP validate. I ran the linux-gnu binary (foremerge --version printed foremerge 0.5.0; tarball SHA-256 e1756edc201149f18ccd4a6aeee8f14a53c648fc00f7aae18191d0e6368fb365). POST /v1/changesets/{id}/validate with {"command":["true"]} returned 400 INVALID_INPUT: raw validation commands are not accepted over HTTP. {"check":"test"} ran the registered true and passed.

foremerge changeset validate <id> -- true still accepts argv and passed on that changeset. --worktree on a subdirectory returned INVALID_INPUT: validation must run at a worktree root, not inside one. There is no GitHub issue for the HTTP body change.

An unknown name is 404 NOT_FOUND. Extra command or worktree fields are still 400 before exec. Register the command with foremerge checks set.