The 2026-05-10 default-ON flip of IMPLEMENTER_DISPATCHER_PREFETCH /
IMPLEMENTER_DISPATCHER_PRECLONE put rich PR context and a pre-cloned
worktree in the wrapper's prompt — but the deep `task` tool chain
(implementation-worker → tier-dispatcher → tier-qwen-med →
task-implementor) re-summarises the prompt at every level, so by the
time task-implementor sees its input only BEGIN_PR_DIFF survives. The
worker still called git-isolator-util (~82 s wasted) and re-issued
Forgejo GETs for data the dispatcher had already fetched.
This change introduces a filesystem-mediated handshake that is immune
to prompt summarisation. The dispatcher writes two sentinel JSON
files per cycle (workspace handoff next to the worktree; PR-context
handoff in /tmp/cleveragents-implementer-handoff/) and the worker
reads them via two new bash-allowed Python scripts. Missing /
malformed / stale sentinels map to empty stdout, which is the
worker's signal to fall through to the legacy GET / git-isolator-util.
New modules:
- tools/_pr_context_sentinel.py: dispatcher-side writer (atomic, with
200 KB per-field truncation and idempotent delete).
- tools/implementer_workspace.py: worker-side reader CLI with
`discover` and safety-checked `cleanup` subcommands.
- tools/implementer_pr_context.py: worker-side reader CLI with `read
--field <name>` for every prefetch field.
Hooked into:
- tools/_pr_clone.py: prepare_pr_worktree writes the workspace
sentinel after worktree-add succeeds; WorktreeHandle.cleanup
removes both worktree and sentinel; new _resolve_branch_for_sha
populates the sentinel's branch field.
- tools/dispatch_implementer.py: _prefetch_prompt writes the
PR-context sentinel; _cleanup_clone_handle removes it.
Two new skills (.opencode/skills/implementer-workspace,
.opencode/skills/implementer-pr-context) and a rewrite of every
"Pre-fetched section" wording in .opencode/agents/task-implementor.md
to call the skills first and fall back to legacy GET only on empty
stdout.
Tests: 54 new (16 workspace CLI + 21 PR-context CLI + 7 sentinel
writer + 10 _pr_clone integration). Full auto_agents suite: 1,123
passed, 3 skipped (was 1,069 before).
Co-authored-by: Cursor <cursoragent@cursor.com>
drew
d386ff4e8b