9b41d51231
Source snapshot: 514ab1975951d94342ea38e64101d5a0f1c51c77
2.0 KiB
type, id, title, status, date, supersedes
| type | id | title | status | date | supersedes |
|---|---|---|---|---|---|
| ADR | 0148 | Cancellable AI agent streams | active | 2026-06-28 |
Context
ADR-0133 gave every AI stream a request-scoped event name so concurrent or rapidly reused renderer sessions do not share Tauri event channels. Users can still start long-running CLI-agent work that spawns local subprocesses, and closing or ignoring the frontend stream only suppresses stale renderer callbacks. Without a backend cancellation path, the selected CLI can keep running after the user has decided to stop the response.
The stop control needs to work across the shared JSON-line runtime and line-oriented adapters such as Antigravity, Kiro, and Hermes without giving the renderer access to arbitrary process ids.
Decision
Tolaria treats the request-scoped AI-agent event name as the cancellation handle for app-managed CLI-agent streams.
The desktop backend wraps stream_ai_agent execution in an AI-agent stream scope. When an adapter spawns a child process, it registers that child under the current scoped stream id through a shared process registry. The renderer can then call abort_ai_agent_stream(event_name) with the same scoped id used for event delivery. The command validates the ai-agent-stream-* prefix and safe character set before killing the registered child, and returns false when no active child is present.
Direct AI-model streams are not registered in this process registry because they do not spawn local CLI children.
Consequences
- The stop button can abort an in-flight app-managed CLI process instead of only ignoring late stream events.
- New CLI-agent adapters that spawn subprocesses must register their child after taking stdout/stderr handles and wait through the registered wrapper.
- The renderer never receives or supplies OS process ids; cancellation remains scoped to validated AI-agent stream names.
- A stop can race with process startup or natural completion, so both frontend and backend stop paths are idempotent.