v0.9.0

A third hooks host. OpenAI's Codex CLI turned out to expose the same six
events as Claude Code, with the same payload and the same output envelope, so
every plugin runs its hooks/ adapter there unchanged — once two things
were found by trying it: a root plugin.json silently disables every hook
on Codex, and stdout that begins with [ is dropped, which was every
message in this collection. Both are fixed here, and the fixes hold on
Claude Code (test.js, and a live claude -p either side of the change).

Measured on Codex before it was written down, as far as a Free plan allowed:
termination 3 of 3 with, 0 of 3 without, the quiet case costing nothing,
through a new scripts/codex-eval.js that needs nothing installed. The
first run also caught the five close scanners rejecting a correct block for a
blank line and a full stop — fixed, with a test. The other fifteen cases are
on the plan's monthly limit; the hook wiring behind them is the one already
measured on Claude Code, and the same file.

Plugin	Version
executive-self-monitoring	1.6.0
epistemic-self-monitoring	0.2.0
persistence-self-monitoring	0.2.0
termination-self-monitoring	0.2.0
coverage-self-monitoring	0.2.0
handoff-self-monitoring	0.2.0
progress-self-monitoring	0.3.0

Every plugin moves a minor: each gained a host, and all seven changed the
shape of what their hooks write.

Added

• Codex as a third hooks host. OpenAI's Codex CLI exposes the same six
  events as Claude Code — SessionStart (with source), UserPromptSubmit,
  PostToolUse, Stop, SubagentStop, SessionEnd — with the same
  stdin payload, the same hooks.json nesting, ${CLAUDE_PLUGIN_ROOT}
  expanded as an alias of its own ${PLUGIN_ROOT}, and the same output
  envelope. So every plugin runs its hooks/ adapter on Codex unchanged; what
  it needed was a manifest (.codex-plugin/plugin.json, pointing at
  skills/ and hooks/hooks.json) and a marketplace index
  (.agents/plugins/marketplace.json, read by
  codex plugin marketplace add). Checked on codex-cli 0.155.1 on Windows,
  end to end: installed from the local marketplace, all four of
  progress-self-monitoring's session events fired inside codex exec, and
  the model repeated the session-start count and the load message back.
  Plugin hooks run on Codex only after a one-time review in /hooks
  (codex exec --dangerously-bypass-hook-trust for scripts); the README
  says so.
• scripts/codex-eval.js — the Codex arm of the behaviour layer. Same
  cases, same graders, same transcript names as the other two runners, and
  like the Claude Code one it measures hooks AND skill. How the WITH arm is
  built was measured first, because the obvious way does not work: a plugin
  installed with codex plugin add keeps its hooks off until someone trusts
  them in the TUI, and the bypass flag does not reach them; a project
  .codex/hooks.json needs the project trusted, and six spellings of a
  -c projects.…trust_level override were all ignored. What works: the
  skill copied into the workspace's .agents/skills/ and the plugin's
  hooks/hooks.json passed as session hooks (-c 'hooks.<Event>=[…]')
  under --dangerously-bypass-hook-trust; both arms under
  --ignore-user-config, which drops installed plugins and keeps the login.
  Nothing under ~/.codex is written. On Windows the runner starts the
  npm package's bin/codex.js with node rather than the .cmd shim, so
  the quoted TOML survives, and it carries one value back out of the user's
  config — [windows] sandbox — without which workspace-write silently
  falls back to read-only and every "work" case answers that it cannot write
  (the first batch lost progress and handoff to exactly that). A ChatGPT
  plan's usage limit arrives on stderr with an empty stdout; the runner stops
  at the first one and says so, instead of spending the rest of the batch on
  dead runs. First numbers, codex-cli 0.155.1 on a Free plan: termination
  3 of 3 with, 0 of 3 without, the quiet case costing nothing; the other
  fifteen cases wait for the plan's monthly limit to reset.

Fixed

• A blank line after the marker, and a full stop after a value, are still
  the block — in all five close scanners. The first Codex run scored a
  correct [TERMINATION CHECK] as malformed twice over. The scanners end a
  block at the first blank line, and the model had put one between the
  marker and the list — which is what markdown looks like when a heading
  precedes a list — so the captured block was empty: "Reason (empty)", "no
  Decision". And it wrote Reason: none., which the enum match read as a
  qualifier on the one value that takes none. Now one blank line right after
  the marker is consumed before the fields are read ([COVERAGE CHECK],
  [EPISTEMIC CLOSE], [HANDOFF], [PLAN CHECK], [TERMINATION CHECK]; a second blank line still ends the block), and a trailing full
  stop is stripped from Reason, Decision and Status before the
  enum is checked. Re-scored, the same transcript passes. Twelve Claude Code
  cases at 100% had said nothing about either, because that model writes the
  list flush against the marker and its values bare.

Changed

• Every hooks/ script writes the envelope, never plain text. The
  prompt and session-start hooks used to write their message bare, which
  Claude Code adds as context; Codex reads stdout that begins with [ as
  JSON, fails to parse it, and drops it — and every message in this
  collection begins with [<plugin> self-monitoring]. Found with three echo
  hooks in one session (TOKEN-A plain seen, [bracket] TOKEN-B not,
  the same text inside hookSpecificOutput.additionalContext seen). Now
  all twelve output sites go through one context(event, text) in
  lib/host.js, the envelope both hosts accept on the events that inject
  context; the five observe hooks already wrote it inline. The text the
  model reads is unchanged; scripts/test.js reads it back through the
  envelope (hook().text) and samples.js quotes the inside.
• The Agent Plugins manifest moves from plugin.json to
  .plugin/plugin.json. Codex 0.155 reads a root plugin.json through
  its Agent Plugins loader, which has no hooks slot, and then ignores
  .codex-plugin/plugin.json — every hook silently off, no warning
  (openai/codex#39895, open;
  the extensions.com.openai.hooks the docs describe is not implemented).
  Four probe plugins in one marketplace settled it: hooks load from
  .codex-plugin/ alone, with or without an explicit hooks field, and
  from nothing when a root plugin.json is present. The spec names only
  the root, so the portable manifest is now a courtesy copy in the location
  Copilot CLI and Goose also read, and scripts/test.js fails on a root
  plugin.json. The README's host table says why.

Full Changelog: v0.8.0...v0.9.0