Why: token budget let the current tool batch run, compaction could split a tool pair or race an append, writes were not crash-atomic, and several MCP and session edges only existed as comments.
Evidence: GOWORK=off go test -count=1 -race ./runtime/ ./runtime/llm/ ./runtime/session/ ./runtime/tools/ ./runtime/mcp/ ./adapters/native/ ./adapters/intentgate/ passed, including the TestR2* cases for budget, replacement, cancel, compaction, SSE, UTF-8, schema, MCP retry, session terminate, poison reload, and registry reload.
Impact: over-budget tool calls are skipped and paired; Stop.Replacement is appended to the session; the intent gate can follow Registry.Reload.
Refs: N5, N6, N7, N8, N9, N11, N12, N15, N16, N17, N18, N19, N21, I9
Co-authored-by: Cursor <cursoragent@cursor.com>
Why: the kernel had no system-tool capability, so deliverable generation
via CLI/Python (the settled product direction) could not run inside
agent-native executions; squad's BashPermission gate had nothing to
guard.
Evidence: go vet ./... clean; go test ./... all ok. Cases cover echo
and non-zero exit reporting, env whitelist isolation (host secrets do
not leak into children), timeout and context-cancel killing the whole
process group promptly, blocklist rejection (sudo/destructive
patterns), 64 KiB head+tail output truncation, python script
persistence under .agent/scripts/, and fail-closed registration (no
interpreter configured = no tool). Adapter tests verify Options.Exec
wiring, per-request Env merge, allowlist stripping, and absence
without Options.Exec.
Impact: native.Options gains Exec *tools.ExecConfig; exec.Request.Env
now flows into child processes; workspace profile gains up to 2 tools
(only when configured). NOT an OS sandbox - isolation stays a host
responsibility, documented in tool descriptions.
Refs: parity-matrix #3/#4; settled product decision (deliverables via
CLI/Python + skills, see archived card feature-exec-interpreters).
weichenandCursor