## Thinking Path
> - Paperclip is the open source app people use to manage AI agents for
work.
> - The local adapter and heartbeat recovery systems decide whether an
agent has a real control-plane mutation path.
> - Sandboxed local adapters split execution between the trusted host
process and the sandbox shell/tool surface.
> - A host-side adapter can still reach Paperclip while the sandbox
shell surface cannot, which leaves agents thinking no endpoint or
credentials are configured even though the host can still post comments.
> - Execution-policy review stages can also remain pending after a
reviewer run finishes without recording a decision.
> - This pull request makes the sandbox bridge available to the actual
shell mutation surface and adds bounded recovery for
terminal-but-still-pending review participants.
> - The benefit is that agents get a real reachable Paperclip API path
where they need it, and stalled review stages become visible recovery
work instead of silently drifting.
## Linked Issues or Issue Description
No exact public GitHub issue matched this combined failure. I searched
for exact and related terms including `cannot reach the Paperclip
control plane`, `execution_review_participant_recovery`, `sandbox
callback bridge`, `review participant in_review`, and `control plane
sandbox`.
Related public issues:
- Refs #8482 for `in_review` liveness invariant recovery.
- Refs #863 for prior agent API-key reachability confusion.
- Refs #248 for the broader sandboxed agent execution model.
Bug summary:
- What happened: a sandboxed local-adapter run could have host-side
Paperclip access while the sandbox Bash/tool surface lacked a reachable
API endpoint or usable run credentials. Separately, a reviewer run could
finish while its execution-review stage remained pending, leaving the
source issue in `in_review` with no decision and no live participant
run.
- Expected behavior: the mutation surface that agents actually use
should receive a run-scoped Paperclip bridge, and pending review
participants should get one bounded normal-model recovery wake before
moving to explicit blocked/source-scoped recovery.
- Steps to reproduce: run a sandbox-backed local adapter that needs
Bash/curl/tooling to call Paperclip from inside the sandbox, or finish
an execution-policy reviewer run without submitting the pending review
decision.
- Deployment mode: local/authenticated private development instance with
sandbox-backed local adapters.
## What Changed
- Changed sandbox callback bridge startup so bridge credentials are
passed through the sandbox runner environment instead of embedded in the
visible `nohup env ...` command string.
- Added adapter-utils coverage proving the sandbox shell can call
Paperclip through the bridge, forwards the host run JWT with
`X-Paperclip-Run-Id`, and does not leak host or bridge tokens into
stdout/stderr, runner command text, or runtime files.
- Added one bounded execution-review participant recovery path for
terminal reviewer runs whose `executionState` remains pending.
- Escalated exhausted or non-invokable review participant recovery to
blocked/source-scoped recovery with dedicated evidence, activity, and
next-action text.
- Documented the mutation-surface reachability contract in
`doc/execution-semantics.md` and updated the Paperclip skill
authentication guidance for sandbox bridge env vars.
## Verification
- `pnpm exec vitest run
packages/adapter-utils/src/execution-target-sandbox.test.ts`
- `pnpm exec vitest run
server/src/__tests__/heartbeat-process-recovery.test.ts
--no-file-parallelism --maxWorkers=1`
- `pnpm --filter @paperclipai/adapter-utils typecheck`
- `pnpm --filter @paperclipai/server typecheck`
- `git diff --check`
- `curl -fsS $PAPERCLIP_API_URL/api/health` returned `status: ok` on the
local instance.
## Risks
- Medium behavioral risk: more `in_review` issues with
terminal-but-pending reviewer runs will now be retried once and then
blocked explicitly instead of remaining quiet.
- Low sandbox bridge risk: credential delivery moved from command text
to the runner environment, which is less leaky but depends on sandbox
providers honoring the env payload for startup commands.
- No database migration is included.
- Full repo build and CI were not run locally before opening the PR;
targeted server/adapter tests and typechecks passed.
## Model Used
OpenAI GPT-5 via the Codex local agent, with repository tool use and
shell-based code execution. The runtime did not expose a precise
context-window value to the agent.
## 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
- [ ] All Paperclip CI gates are green
- [ ] 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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