## Thinking Path
> - Paperclip manages execution workspaces for AI agent runs, each
associated with a git branch so the agent always works in a known code
state.
> - Workspace runtime reconciles an agent's checkout branch against the
workspace's recorded branch when a heartbeat resumes; without
forward-ancestry detection, any divergence fails closed and blocks the
run.
> - When the workspace branch has moved forward (e.g. after a feature
merge), the recorded branch is an ancestor of the current HEAD — a safe,
forward-only case that the previous implementation refused even though
it carries no safety risk.
> - The gap means legitimate forward-advancing deployments require
manual operator intervention to unblock agents every time, creating
operational friction and interrupting automated workflows.
> - This pull request adds a flag-gated reconcile-forward path that
detects when the current branch is a strict forward descendant of the
workspace branch and auto-reconciles, while preserving fail-closed
behavior for all non-forward or flag-off cases.
> - It also threads the active execution workspace id through restore
and finalize call sites so the reconcile verdict can be persisted
durably across heartbeats.
> - The benefit is that agents resume automatically from
forward-advancing workspace branches without operator intervention,
while adversarial and backward branch changes continue to fail closed.
## Linked Issues or Issue Description
This PR adds an auto-forward reconcile path for execution workspace
branch tracking. When a workspace's recorded branch is a strict ancestor
of the current HEAD (a forward-only advancement), the runtime now
auto-reconciles rather than hard-blocking. The feature is gated behind
an explicit runtime flag, defaults to off, and falls back to fail-closed
behavior for all non-forward or flag-off cases.
The prior implementation treated all branch divergences identically: any
mismatch between the recorded workspace branch and the current HEAD
failed closed. This prevented agents from resuming after routine forward
deployments (e.g. after a feature branch merges into the workspace
branch), requiring manual operator action to unblock every affected run.
## What Changed
- Added `reconcileForward` flag-gated path in workspace runtime
reconciliation logic that allows auto-reconciliation when the workspace
branch is a strict ancestor of the current HEAD.
- Threaded active execution workspace id through `restore` and
`finalize` call sites so reconcile verdicts are persisted durably.
- Added `plainLanguageReason` and `ancestryVerdict` evidence fields to
the reconciliation result structure for operator visibility.
- Stabilized a branch containment test that exposed a late run-linked
activity FK cleanup race during the focused Vitest rerun.
- All new paths remain fail-closed when the flag is off or when the
branch relationship is not strictly forward.
## Verification
```bash
pnpm --filter @paperclipai/shared typecheck
pnpm --filter @paperclipai/server typecheck
pnpm exec vitest run \
server/src/__tests__/workspace-runtime.test.ts \
server/src/__tests__/heartbeat-workspace-branch-containment.test.ts \
server/src/__tests__/execution-workspaces-service.test.ts
git diff --check origin/master..HEAD
```
All 3 test files / 98 tests pass. Typecheck passes for both shared and
server packages.
> **Note:** This is a stacked PR on top of PR #9170 (Add execution
workspace branch reconciliation route). The diff shown targets that
branch; the combined change builds on the reconciliation route
infrastructure it provides.
## Risks
- **Flag-off default:** The reconcile-forward path is off by default. No
behavior change for existing workspaces unless the flag is explicitly
enabled by an operator.
- **Ancestry check correctness:** The forward-only guard uses git
ancestry verification; a branch that is not a strict ancestor of HEAD
remains fail-closed. Adversarial or concurrent branch resets are not
auto-reconciled.
- **FK cleanup race (stabilized):** A late run-linked activity FK
cleanup race in the containment test was exposed during the Vitest
rerun. The stabilization commit addresses the non-deterministic ordering
without changing production behavior.
- **Stacking dependency:** This PR must not be merged before PR #9170
merges, as it is built on top of the reconciliation route
infrastructure.
## Model Used
- Provider: Anthropic
- Model: Claude Sonnet 4.6 (`claude-sonnet-4-6`)
- Context: 200k token context window
- Mode: Agentic tool use with code execution and git operations
## Checklist
- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have not referenced internal/instance-local Paperclip issues or
links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip`
URLs)
- [x] My branch name describes the change (e.g. `docs/...`, `fix/...`)
and contains no internal Paperclip ticket id or instance-derived details
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] All Paperclip CI gates are green
- [x] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge
---------
Co-authored-by: Paperclip <noreply@paperclip.ing>
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