Why: Old tool results were filling the window, compaction could split a tool group or commit a stale summary, and reminders arrived as extra user messages.
Evidence: Compaction retries a conflict and opens the circuit after three failures; clearing keeps the last five tool results; a stale file write is rejected; RPC reports started, queued, or handled.
Impact: Requests over the context window replace older tool results with a placeholder. Rewriting an existing file now requires a read in the same run. Subagent text over 32000 characters is capped.
Refs: feature/context-engineering
Co-authored-by: Cursor <cursoragent@cursor.com>
Why: complete agents delegate; the kernel must not nest executions
itself (orchestration stays with the host per the agent-execution
standard), so the missing piece is a port plus a tool face.
Evidence: go vet ./... clean; go test ./... 14 packages ok. Cases:
nil factory registers nothing, full delegation field round-trip
(goal/inputs/write_scope/non_goals/done_criteria/deliverables) with
sorted file list in the result text, sub-agent failure and factory
error propagation, schema-required goal rejection, pre-canceled
delegations never starting, and adapter end-to-end wiring through
Options.Subagent.
Impact: new runtime/subagent package (Request/Result/Factory); the
delegation message set matches the agent-execution delegation clause
(sub-tasks derive no extra permissions; budget fields are host-set);
native.Options gains Subagent.
Refs: plan B8; standards/agent-execution.md delegation section.
weichenandCursor