ADR 0011: Freeze host RPC, storage ownership, and mode defaults

• Status: Accepted; mode-profile clause superseded in part by ADR 0053
• Date: 2026-07-25

Context

After baseline 0.3.0, implementation still depended on several high-impact defaults:

• Electron ↔ Rust transport
• SQLite ownership
• default interaction mode
• former restricted-profile tool split (superseded by ADR 0053)
• permission timeout behavior

Decision

Freeze the following defaults for implementation:

1. Transport = Rust sidecar + stdio JSON-RPC (NDJSON)
2. SQLite ownership = Rust host-core only
3. Default mode = Agent
4. The former restricted profile was read-only; this mode-profile clause is superseded by ADR 0053, which supersedes the historical operating-state decision in ADR 0052 and replaces it with the current Plan workflow
5. Permission timeout = 120s deny
6. Session grants = by toolName
7. First release platform = macOS arm64 only
8. TS schema = typebox
9. i18n = i18next

Consequences

Positive

• M1/M2 can proceed without re-litigating core choices
• Clear process and data ownership
• Explicit host-owned operating-state and permission policy

Negative

• JSON-RPC text protocol may later need binary upgrade
• Exclusive Rust DB ownership requires mature host RPC coverage early

Related docs

• docs/spec/08-meta/decisions-log.md
• docs/spec/03-runtime/06-host-rpc-protocol.md
• docs/spec/03-runtime/07-process-model.md
• docs/spec/04-ux/03-permission-ux.md