Agentic Sandbox v2026.7.2

Agentic Sandbox v2026.7.2

Released: 2026-07-06 Tag: `v2026.7.2` Previous: `v2026.7.1` Compare: `v2026.7.1...v2026.7.2`

What this release is

v2026.7.2 tightens Observe/Drive terminal control and reconnect behavior. The formal session registry now grants one controller lease at a time, exposes membership and liveness metadata through the list surfaces, and gives CLI and dashboard clients enough attach metadata to reconnect without route guessing.

Highlights

  • Singleton controller lease: the formal session registry grants one live

controller; later controller requests attach read-only as observers until the lease is released or stale state is reaped.

  • Reconnect-ready session lists: agent-scoped REST session lists and

WebSocket session listings include PTY attach URLs, subprotocols, controller and observer membership, replay state, and client lag.

  • Cleaner late joins: new observers replay from the latest keyframe when

available, or from the oldest retained ring frame when no keyframe exists yet.

  • Safer CLI attach: `sandboxctl session attach --controller` now treats a

server downgrade as read-only and stops forwarding stdin.

  • Dashboard visibility: session cards show controller lease state,

observer counts, and replay sequence state, and v2 attach prefers listed PTY URLs.

  • Retry-safe create: interactive session creation supports

`Idempotency-Key` caching for successful responses.

Install / upgrade

curl -fsSL https://github.com/jmagly/agentic-sandbox/releases/download/v2026.7.2/agentic-sandbox-install.sh \
  | bash -s -- --version v2026.7.2

Direct package installs:

sudo apt-get install ./agentic-sandbox_2026.7.2-1_amd64.deb
sudo dnf install ./agentic-sandbox-2026.7.2-1.x86_64.rpm

Upgrade matrix

AudienceAction
CLI usersUpgrade `sandboxctl` with management so role downgrades and richer session listings render correctly.
Dashboard usersRefresh the dashboard bundle after management upgrade to see lease and replay metadata on existing sessions.
API clientsPrefer `GET /api/v1/agents/{id}/sessions` attach metadata and honor server-granted roles before writing.
OperatorsUpgrade management first, then agent clients. Existing sessions can continue, but reconnect metadata is most useful after both sides run this release.

Verification

After publication, verify the release assets:

scripts/verify-release-assets.sh v2026.7.2 --skip-ghcr

Check local behavior with:

sandboxctl session list --agent <agent-id> --json
sandboxctl session attach <session-id> --controller

The session list should include `pty_ws_url`, `membership`, and `liveness`. When another live controller holds the lease, attach should report a read-only observer downgrade and stdin should not be forwarded.

Notes

  • This release changes the formal session registry from multi-controller

semantics to a singleton controller lease. Clients that relied on concurrent writers should move to explicit controller handoff.

  • The legacy PTY bridge remains available, but new clients should use the

listed v2 PTY metadata where possible.