Codex 0.147 is the release where Agent Plugins acquired package-manager behavior: portable installation and one discovery surface spanning local, personal, workspace and remote catalogs [E1]. The runtime can now find packages across those locations instead of treating each catalog as a separate island [E1]. The release also converts a plugin’s MCP configuration into host configuration, carrying its tool wiring across the installation boundary [E1]. In practical terms, the published format has acquired released distribution machinery [E1].
The harder boundary appears one process later. The Agent Plugins specification says it does not sandbox a plugin subprocess or restrict paths supplied at runtime [E3]. Its launch note also leaves installation, distribution, policy, user experience and client-specific capabilities to each client [E2]. Permissions, credential handling and activation consequently remain host responsibilities in this model, so portability moves the package while the trust decision stays local [E2][E3].
That division recreates the old package-manager security problem inside an agent runtime. A portable plugin may carry MCP wiring across clients, but the standard does not itself confine a subprocess once a host chooses to launch one [E3]. It also declines to restrict arbitrary runtime paths, leaving filesystem and process controls with the host [E3]. Two clients can therefore accept the same package while imposing materially different security policy around its execution [E2][E3].
Cross-vendor evidence is no longer hypothetical. AWS says Kiro is rolling out support for the Agent Plugins specification [E5]. Kiro says a plugin published to the standard is installable in Kiro as a power, showing an independent runtime consuming the format through its existing extension layer [E6]. The project’s governance also bars any single vendor from controlling a majority of Core Maintainer seats, an institutional design consistent with portability beyond one host [E4].
Release status is the remaining qualification. The Record contains rollout language from AWS and an installability claim from Kiro, but it does not establish a tagged or stable Agent Plugins 1.x release from a non-OpenAI runtime by the 8 August cutoff [E5][E6]. Kiro may be translating standard packages into its existing Powers layer, which would prove useful compatibility without establishing that the surrounding runtime has stabilized the whole plugin contract [E6]. That gap matters because distribution, policy and client-specific behavior are explicitly left to the implementer [E2].
House probability is p=0.84 that the missing release evidence arrives by 31 October 2026. YES settles if, by 23:59 UTC that day, a non-OpenAI runtime publishes a tagged or stable Agent Plugins 1.x release that accepts the specification’s MCP component, including stdio where that runtime supports subprocesses. NO settles if no such release exists by the deadline; previews, rollout announcements, unreleased branches and metadata-only importers do not count. Released Codex package behavior, Kiro’s independent installability claim and AWS’s rollout statement support the call, tempered by the still-host-specific security and activation surface [E1][E2][E5][E6].
A lower p=0.71 counter-case holds that the same evidence can stop at compatibility and fail to reach stable 1.x productization by the deadline. AWS’s wording remains “rolling out,” while Kiro frames the imported object as a “power,” leaving room for an adapter layer to mature without a clean tagged release on this schedule [E5][E6]. The governance rule broadens stewardship but does not force any runtime to ship on a date [E4]. Codex has made the package portable; every host still owns the process it launches [E1][E2][E3].