---
id: SAND-WP-0015
type: workplan
title: "Provide a pinned bwrap rein runtime and private state"
domain: infotech
repo: sand-boxer
status: blocked
owner: codex
topic_slug: bwrap-runtime-and-private-state
created: "2026-09-05"
updated: "2026-09-05"
state_hub_workstream_id: "d3f12387-fd23-58f0-b979-9c811507614d"
---

# Provide a pinned bwrap rein runtime and private state

Implement the runtime prerequisites returned by Glas in `GLAS-WP-0012` and
`docs/local-profile-acceptance.md`. Continue owner work `SAND-WP-0014-T05` and
live residual `GLAS-IN-0002`. Runtime startup is a separate acceptance gate
from credential delivery, enforced provider egress, and a real model task.

## Mount an owner-selected, digest-pinned Python runtime

```task
id: SAND-WP-0015-T01
status: done
priority: high
state_hub_task_id: "93e4aad8-ba9b-5850-93d4-b5bf78ac8978"
```

Add exact artifact verification to trusted extension configuration and mount
the standalone runtime read-only at a fixed namespace path. Reject altered
content/modes, unexpected files, escaping symlinks, special files, and source
or workspace overlap. A caller cannot choose runtime paths through exec input.
Provide a non-editable rein-aharness/llm-connect bundle builder with recorded
source revisions and resolved dependency versions.

Completed 2026-09-05. `extensions/runtime.py` verifies complete artifact
contents/modes before a read-only mount; the builder installed committed
rein-aharness `1429db5` and llm-connect `0056094` without editable source paths.
Candidate digest and source/package evidence are in `docs/bwrap-runtime.md`.

## Keep writable runtime state outside the repository

```task
id: SAND-WP-0015-T02
status: done
priority: high
state_hub_task_id: "c8a689f8-bdf2-57a2-8521-a1c0ca44e750"
```

Create private mode-0700 HOME/config/cache/state/tmp directories within the
namespace, preserve them across exec requests, and remove them with teardown.
Keep the command environment sanitized and disable Python user-site/bytecode
writes. Fail closed on profile network/setup-credential declarations that the
current bwrap implementation cannot honor.

Completed 2026-09-05. Mode-0700 namespace HOME and XDG/TMP directories sit
outside the copied Git tree. Explicit runtime PATH selection remains owner
controlled. Unsupported egress/default-allow and setup credentials now refuse
before workspace creation; regression tests cover these boundaries.

## Verify the real rein runtime and owner regression paths

```task
id: SAND-WP-0015-T03
status: done
priority: high
state_hub_task_id: "1a3002f6-c6a8-59d0-9d38-942028419de5"
```

Run `make check`, the existing authenticated cross-request owner smoke, and a
real runtime startup smoke. Verify the actual rein CLI and adapter imports,
read-only runtime, private HOME, clean worktree, absent source, loopback-only
network, and teardown. Keep the production Glas profile blocked.

Completed 2026-09-05. `make check`: lint clean, 132 tests passed. Authenticated
owner API smoke `223db65b` returned HTTP 200 and proved exact consumer identity,
stdin delivery, absent source, loopback-only network and complete teardown.
Pinned runtime smoke `d4de9531` ran the actual rein CLI and imported its Claude
adapter, proved read-only runtime/private HOME/clean worktree, retained private
state across a second exec, and removed the workspace. No model call or
credential acquisition occurred; T04 remains waiting.

## Resolve Claude credentials, enforced egress, and production acceptance

```task
id: SAND-WP-0015-T04
status: wait
priority: high
state_hub_task_id: "58817ef6-76d9-5e34-908f-c024e6c99f93"
```

The 2026-09-05 routing lookup found no concrete Anthropic/Claude workload lane.
The generic OpenBao template is not a delegable lane; the OpenRouter AppRole
belongs to another rein. Credential owner railiance-platform/OpenBao plus
rein-aharness must establish a concrete Claude-compatible route and delivery/
revocation contract before values can be requested or supplied to the runtime.

Sand-boxer must then implement the matching enforced provider egress contract
(including DNS/TLS and denied-destination proof) and pin/deploy the actual
Claude executable. No unrestricted-network or interactive-login substitute is
permitted. Review the deployed runtime/profile with Glas, run its real-rein
acceptance fixture, and update only the proven profile's readiness. No
production schedule is enabled by the runtime-startup smoke.

This task and SAND-WP-0014-T05 remain open until those gates pass. The detailed
return contract and runtime proof are in `docs/bwrap-runtime.md`; the live
cross-repo residual remains `GLAS-IN-0002`.

## 2026-09-05 transport implementation evidence

T04 remains waiting on owner machine authentication, protected credential
delivery, pinned Claude startup and the real model proof. CCR-2026-0016 custody
is confirmed by a metadata-only check of live version 2; no value was read.
HTTPS egress is now implemented as an exact owner/profile allowlisted CONNECT
proxy while retaining an isolated network namespace. Non-secret live smoke
sandbox e290e788 verified provider TLS response, undeclared destination and
direct-IP denial, and proxy/workspace teardown. See docs/bwrap-egress.md.