Agentic Sandbox v2026.8.9

Agentic Sandbox v2026.8.9

Released: 2026-08-30

Tag: `v2026.8.9`

Previous tag: `v2026.8.8`

Compare: `v2026.8.8...v2026.8.9`

Highlights

  • Serve A2A 0.3 and 1.0 clients concurrently, with explicit version

negotiation and version-correct HTTP+JSON wire models.

  • Prevent cross-instance task access by binding task operations and related

resources to their owning executor instance.

  • Constrain A2A push callbacks to public Internet HTTPS destinations with

per-attempt DNS validation and connection pinning, redirects disabled, and bounded delivery work.

  • Qualify Gitea 1.27 same-ref concurrency with retained wait, cleanup, and

expected-failure evidence.

  • Remove exact orphaned Celld qualification DHCP reservations while preserving

active, retained-storage, and unrelated targets.

Upgrade

Upgrade `agentic-mgmt`, `agent-client`, and `agentic-cli` together:

curl -fsSLO https://github.com/jmagly/agentic-sandbox/releases/download/v2026.8.9/agentic-sandbox-install.sh
bash agentic-sandbox-install.sh --version v2026.8.9

A2A 0.3 clients do not need to change immediately. To adopt A2A 1.0, discover the signed Agent Card, select its 1.0 HTTP+JSON interface, send `A2A-Version: 1.0`, and use the 1.0 ProtoJSON model. Keep the advertised 0.3 interface as the rollback path during migration.

Deployments that enable push callbacks must permit only the approved outbound TCP 443 path and deny private, special-use, control-plane, and metadata ranges at the network layer. Application validation remains enabled even when an egress proxy is present.

Verification

Verify downloaded release assets and public images using the release verification guide. For A2A behavior, confirm that the Agent Card advertises both interfaces, 1.0 responses carry `A2A-Version: 1.0`, and existing headerless 0.3 requests retain their legacy representation.

The retained conformance lane runs the local A2A 0.3 suite and the pinned upstream A2A 1.0 TCK independently. Push-callback policy tests cover private and special-use IPv4/IPv6 destinations, mapped and encoded forms, mixed DNS answers, rebinding transitions, redirect refusal, and normal public HTTPS.

Operational status

Celld remains experimental, disabled by default, and production `NO-GO`. The authorized live campaign still has QEMU-path failures tracked in #764, so this release does not claim exact-head Celld qualification or promotion.

Rollback

Rollback management, agent, and CLI binaries together to v2026.8.8. No data migration is performed by this release. A2A 0.3 remains available throughout the rollback window.

Full notes: CHANGELOG entry 2026.8.9.