paperclip/packages/adapter-utils
Nicky Leach d1ba17eeca
fix(adapter-utils): fail fast when the sandbox control channel is lost mid-turn (#13158)
## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work
> - Adapter utilities run agent turns and report their results to the
control plane
> - A lost sandbox control channel can leave an agent turn without a
result
> - The host then waits for the full adapter timeout instead of
reporting the loss
> - This pull request adds a push loss signal and a bounded host wait
> - The benefit is a prompt failure terminal when the agent stops
answering

## Linked Issues or Issue Description

**What happened?**

A sandbox control channel loss during an Agent Client Protocol turn left
the host waiting for the four-hour adapter execution timeout.

**Expected behavior**

The host should detect the terminal channel loss, stop the turn, and
report a safe failure without waiting for the agent.

**Steps to reproduce**

1. Start an Agent Client Protocol turn through a sandbox adapter.
2. Close the duplex control channel while the turn remains active.
3. Observe the host response before the adapter timeout expires.

**Paperclip version or commit**

Test the pull request commit set at
`10b6bbc5525a79fd575298607dd5a25ae448fc8a`.

**Deployment mode**

The change applies to sandbox-backed adapter execution.

## What Changed

- Add `onLoss(listener)` to the duplex bridge handle.
- Register the loss listener at turn start and read losses latched
before turn start.
- Cancel the turn on loss and arm a 30-second host deadline.
- Close the stream locally when the deadline wins and create a host
terminal.
- Derive the public error from the closed `DuplexLossReason` enum.
- Add tests for loss order, cancellation, timeout, and safe error
output.

## Verification

- Run `pnpm --filter @paperclipai/adapter-utils exec tsc --noEmit`.
- Run `pnpm --filter @paperclipai/adapter-utils exec vitest run
src/acpx-engine/execute.test.ts -t "run-disposition seam"`.
- Confirm that the full pull request workflow passes.

## Risks

The new deadline changes a lost-channel path from a long wait to a
host-built failure after 30 seconds. Orderly completion keeps its
existing behavior. The deadline race against a pending `turn.result` has
no direct test.

## Model Used

OpenAI Codex, GPT-5, with tool use and code execution. The runtime does
not expose a more specific deployment version or context-window size.

## 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>
2026-09-10 15:37:05 -07:00
..
src fix(adapter-utils): fail fast when the sandbox control channel is lost mid-turn (#13158) 2026-09-10 15:37:05 -07:00
CHANGELOG.md
README.md
package.json feat(connections): add self-serve intent runtime (#12345) 2026-08-29 12:08:34 -05:00
tsconfig.json

README.md

@paperclipai/adapter-utils

Shared utilities for Paperclip adapters: process spawning, environment injection, sandbox/SSH transport, workspace sync, and the round-trip helpers that move code between the local execution-workspace cwd and wherever the agent actually runs.

For the adapter-author guide see docs/adapters/creating-an-adapter.md and the in-repo notes at packages/adapters/AUTHORING.md.

No-remote-git contract

The local execution-workspace cwd is the only persistence boundary across runs. No adapter may depend on a git remote for cross-run state.

Adapters that run the agent on a different host should use the SSH round-trip helpers in src/ssh.ts:

  • prepareWorkspaceForSshExecution({ spec, localDir, remoteDir }) — bundles the local cwd (tracked files, dirty edits, untracked additions, and the git history needed to reconstruct it) to remoteDir before the run starts. Runs with no git remote configured.
  • restoreWorkspaceFromSshExecution({ spec, localDir, remoteDir, ... }) — syncs the remote cwd back into localDir after the run, including any new commits the agent created. Also runs with no git remote configured.

prepareRemoteManagedRuntime in src/remote-managed-runtime.ts wraps both calls for adapters that want a per-run remote workspace and an automatic restoreWorkspace() finally hook.

The invariant is pinned by the no-remote-git contract case in src/ssh-fixture.test.ts, which asserts that a remote-only commit propagates to the local worktree through the prepare → restore round-trip with no git remote configured at any point. Do not regress that test.