paperclip/packages/plugins/sandbox-providers/daytona
Nicky Leach 10d2781a29
feat(sandbox): add the duplex bridge broker, gated transport selection, and fixed observability (#11769)
## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work.
> - Sandbox adapters provide controlled execution for untrusted provider
environments.
> - The sandbox channel needs one persistent duplex transport with
strict host control.
> - The transport must remain off unless the instance setting and
provider capability both allow it.
> - The host must detect loss, bound resource use, and expose only safe
telemetry.
> - This pull request adds the broker, gated selection, kill-switch
wiring, fixed observability, and real-process proof.
> - The benefit is safer sandbox execution with bounded failure behavior
and inspectable transport results.

## Linked Issues or Issue Description

No public issue exists for this change. The related pull requests are
#11738 and #11750.

**Problem or motivation**

The sandbox duplex channel needs a host-controlled broker, strict
transport gates, bounded provider input, and safe loss telemetry.
Without these controls, a provider can cause replay, resource growth,
unsafe endpoint selection, or data exposure through telemetry.

**Proposed solution**

Add a host broker with nested time limits, request limits, one-shot
loss, and per-id deduplication. Select duplex transport only when the
instance setting and provider capability both equal true. Assign the
endpoint and nonce on the host. Reject invalid readiness data and use
the file bridge on failure. Add fixed redacted telemetry and a
real-process end-to-end test harness.

**Alternatives considered**

Keep the file bridge as the only transport. This avoids new channel
behavior but does not provide persistent duplex operation for supported
sandbox providers.

**Roadmap alignment**

This change supports the Cloud / Sandbox agents section in ROADMAP.md.

## What Changed

- Add the duplex bridge broker with bounded forward, response, and
gateway wait budgets.
- Bound concurrent requests, lifetime requests, and request-id bytes
before retention or forwarding.
- Select duplex transport only when both required gates are true.
- Assign the loopback port and nonce on the host and enforce a
liveness-only READY frame.
- Fall back to the file bridge after invalid readiness, contamination,
bind failure, or timeout.
- Carry the kill switch through the server, acpx engine, and six local
adapters.
- Add fixed, redacted duplex telemetry with a provider allowlist.
- Add a real-process end-to-end harness for readiness, round trips,
loss, and teardown.
- Add regression coverage for limits, loss, UTF-8 splits, concurrency,
and telemetry dimensions.

## Verification

- Adapter-utils, server, and Daytona typechecks pass locally.
- Adapter-utils tests pass, including the codec, broker,
execution-target sandbox, and real-process harness.
- Server kill-switch tests pass.
- Live Daytona tests pass with the required provider key and skip
without that key.
- The root pnpm-lock.yaml file has no diff.
- The branch contains ten commits after origin/master.

## Risks

- Duplex transport remains disabled unless both gates equal true.
- A provider remains an untrusted boundary and needs least-privilege
credentials and quotas.
- The server telemetry recorder stays deferred; the default recorder
does nothing.
- A provider that pre-binds the host port causes a fail-closed fallback
to the file bridge.
- The change adds no database migration and changes no root lockfile.

## Model Used

OpenAI GPT-5, exact model family GPT-5, large context window, reasoning,
and tool use. The model assisted with Git handoff validation and PR
preparation. The implementation commits came from the engineering
worktree.

## 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/... or 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
- [x] I searched the GitHub PR list for similar PRs and confirmed this
is not a duplicate

---------

Co-authored-by: Paperclip <noreply@paperclip.ing>
2026-08-22 09:01:31 -07:00
..
src feat(sandbox): add the duplex bridge broker, gated transport selection, and fixed observability (#11769) 2026-08-22 09:01:31 -07:00
DIRECTORY-CONSTRAINT-FINDINGS.md feat(plugin-daytona): persistent session model with plain command dispatch (#10941) 2026-08-06 17:38:00 -07:00
README.md fix(daytona): replace bwrap user-namespace with su privilege drop (#10805) 2026-08-03 21:17:17 -07:00
package.json fix(build): enforce Node 24 across Paperclip (#11792) 2026-08-21 10:17:52 -07:00
tsconfig.json feat(sandbox): add the duplex bridge broker, gated transport selection, and fixed observability (#11769) 2026-08-22 09:01:31 -07:00
vitest.config.ts Add reusable sandbox custom images (#8794) 2026-06-30 09:57:49 -07:00

README.md

@paperclipai/plugin-daytona

Published Daytona sandbox provider plugin for Paperclip.

This package lives in the Paperclip monorepo, but it is intentionally excluded from the root pnpm workspace and shaped to publish and install like a standalone npm package. That lets operators install it from the Plugins page by package name without introducing root lockfile churn for Daytona's SDK dependencies.

Install

From a Paperclip instance, install:

@paperclipai/plugin-daytona

The host plugin installer runs npm install into the managed plugin directory, so transitive dependencies such as @daytonaio/sdk are pulled in during installation.

Configuration

Configure Daytona from Instance Settings -> Environments, not from the plugin's plugin page.

  • Put the Daytona API key on the sandbox environment itself.
  • When you save an environment, Paperclip stores pasted API keys as company secrets.
  • DAYTONA_API_KEY remains an optional host-level fallback when an environment omits the key.
  • Optional apiUrl and target settings map directly to the Daytona SDK/client configuration. If apiUrl is omitted, the Daytona SDK uses its default endpoint.

Notes:

  • The current published Daytona SDK package is @daytonaio/sdk.
  • The driver supports both snapshot-based and image-based sandbox creation. If both are set, validation rejects the config as ambiguous.
  • Reusable leases map to Daytona stop/start semantics. Non-reusable leases are deleted on release.

Advisory bwrap wrapper

The driver wraps a sandbox command with an advisory bubblewrap (bwrap) wrapper. The wrapper is advisory, best-effort, and automatic. At lease time the driver probes the sandbox for the wrapper capability and records the result on the lease metadata. At execute time the driver wraps the command when the capability is present. The command builder is a pure function.

  • The wrapper adds no security. The ephemeral sandbox stays the only security posture. The wrapper only gives an agent real-time feedback when the agent tries to change a file that the ephemeral sandbox will not keep.
  • The read-only root is a feedback signal. The wrapper binds the root as read-only (--ro-bind / /) and re-binds only the writable directories. A write to a path outside the writable set fails at once, so the agent learns the change is not durable.
  • A capability probe records the wrapper capability. No configuration field turns it on. At lease time the driver reads the sandbox username with id -un, then probes the end-to-end bwrap capability by running sudo -n bwrap with a workspace bind and an su user switch. It stores bwrapAvailable and sandboxUsername on the lease metadata.
  • The probe is best-effort. A missing bwrap binary, a missing passwordless sudo -n rule, a missing su binary, or an inaccessible workspace bind records bwrapAvailable: false and never fails the lease.
  • The writable set is the workspace plus the read-write sync destinations. The wrapper binds the workspace directory read-write as the baseline; the workspace is always durable. It adds the read-write sync destinations that a sync-in recorded for the same lease. The set deduplicates the directories. The baseline keeps a safe result even when the collected set is empty.
  • The wrapper runs at execute time when the capability is present. The driver wraps the command only when the lease reports bwrapAvailable: true and a username is known. It binds the workspace and the read-write sync destinations, keeps the root read-only for feedback, and re-binds the stdin file after the fresh /tmp. It runs the plain command when the capability or the username is missing. A wrap without a username would run as root and give the agent's files root ownership, so the driver keeps the plain command in that case.

Operator enablement (advisory bwrap)

The advisory bwrap wrapper needs three run-time prerequisites on the image or snapshot. The repository does not build the Daytona image or snapshot. It references an external image or snapshot. So the three prerequisites are image facts, not code facts. The runtime only probes for the capability and degrades when the capability is absent.

The wrapper is advisory, best-effort, and automatic. It adds no security. The ephemeral sandbox model stays the only security posture. A missing prerequisite degrades to the plain command. It never fails the lease. So the enablement below is optional. It gives the agent real-time feedback on a non-durable write. It does not change the security posture.

The install and the sudoers change are environment provisioning at the image or snapshot layer. Route them to DevOps through the board. Do not run the steps from the runtime and do not commit a provisioning script to the repository.

1. Install the bubblewrap package

The repository does not state the Daytona base distribution. Confirm the distribution on the referenced image or snapshot first, then run the matching command:

# Debian/Ubuntu
apt-get install -y bubblewrap
# Alpine
apk add bubblewrap
# Fedora/RHEL
dnf install -y bubblewrap

Confirm the binary path is /usr/bin/bwrap after the install.

2. Add the passwordless sudoers rule

The wrapper runs bwrap as root with sudo -n. Add this exact sudoers line. Use the real sandbox user name and the real bwrap path:

<sandbox-user> ALL=(root) NOPASSWD: /usr/bin/bwrap

The <sandbox-user> is the account name that id -un returns inside the sandbox. Use the account name, not a numeric id, in the sudoers line. The probe reads the username with id -un. The driver resolves the sandbox work directory first, then the user home directory. It uses /home/daytona only as a fallback default when both are empty. Confirm the real home directory for your image or snapshot. Install the sudo and util-linux (for su) packages in the image or snapshot if they are absent.

3. Verify the prerequisites

Run this exact command as the sandbox user, replacing <sandbox-user> and <workspace> with real values:

sudo -n bwrap --ro-bind / / --bind-try <workspace> <workspace> -- su -s /bin/sh <sandbox-user> -c true

A zero exit code means all prerequisites are met. A non-zero exit code means one prerequisite is missing. The wrapper then stays off and runs the plain command.

The probe binds the workspace directory and switches to the sandbox user with su. This matches the exact invocation the live wrapper uses, so a passing probe guarantees that execution commands will also succeed.

Local development

cd packages/plugins/sandbox-providers/daytona
pnpm install --ignore-workspace --no-lockfile
pnpm build
pnpm test
pnpm typecheck

These commands assume the repo root has already been installed once so the local @paperclipai/plugin-sdk workspace package is available to the compiler during development.

Package layout

  • src/manifest.ts declares the sandbox-provider driver metadata
  • src/plugin.ts implements the environment lifecycle hooks
  • paperclipPlugin.manifest and paperclipPlugin.worker point the host at the built plugin entrypoints in dist/