Alassane
cc33b2a813
Co-authored-by: ayattara <alassane.yattara@savoirfairelinux.com> Co-authored-by: Carlos Florencio <carlosmflorencio@gmail.com>
2.2 KiB
ADR-2026-09-14-explicit-plugin-utility-selection: Explicit plugin utility selection
Status: accepted Date: 2026-09-14 Area: protocol
Context
PR #2870 makes Host.InvokeUtilityAgent read the calling plugin's configuration to choose an execution profile. The method arguments do not expose that selection. Settings > Utility Agents already provides a default profile. The user rejected implicit configuration routing and requested an explicit override with default behavior when omitted.
Decision
Plugins own persistence of their preferred profile and pass any override with the invocation. The host uses the platform default only when the request omits a profile. It never reads plugin configuration for execution selection. An invalid override fails without fallback. The existing agent_invoke permission remains required. This supersedes ADR 0048's configuration-based selection and compatibility rules. Its sessionless execution boundary remains applicable. The transport must reject clients requesting unsupported selection semantics before execution. Silent downgrade is forbidden.
Consequences
Callers can reason about execution from arguments and the platform default. Settings and execution ownership are separate. Old prompt-only clients use the default on the revised host. Clients that need their saved selection must send it explicitly. The SDK interface changes for implementers. Updated clients require a host supporting the new wire method. General agent execution with cwd remains outside this utility completion contract.
Alternatives considered
- Implicit plugin configuration routing: rejected because the call hides its execution selection.
- Always use the default: rejected because plugins need explicit per-call overrides.
- Keep legacy configuration fallback: rejected because it preserves the hidden behavior the user removed.
- Add only an optional field to the old RPC: rejected because old servers can ignore that field and execute the wrong profile.