This session proved agy does not need a bespoke scaffold: `agy plugin
install <repo-url>` imports the Claude Code plugin's skills AND its
SessionStart hook, which agy runs — so the bootstrap fires the Shape-A way
with no new files (verified: brainstorming auto-triggers on agy 1.0.3).
Replace the doc's now-false 'agy ships a generated ANTIGRAVITY.md context
file via .antigravity-plugin/install.sh' framing throughout:
- Part 2: Antigravity is the marquee 'you may not need a new directory'
case; install the existing plugin and run the acceptance test before
building anything.
- Part 4: add the inverse-of-a-fork-warning (a derived harness may inherit
the parent's hook execution); replace the routing row with
'installs an existing plugin directly, including its hook'.
- Step 5 / Part 6: bootstrap escalation now leads with 'check for an
inherited hook'; if a manifest names a context file, point it at the real
using-superpowers/SKILL.md — never generate a wrapped copy at install time.
- Appendix A: add the Antigravity row. Appendix B: add two gotchas.
Note: references to references/antigravity-tools.md and tests/antigravity/
depend on PR #1657 landing on dev.
An evergreen guide for adding support for a new harness (IDE, CLI, or agent
runner). Teaches the invariants — automatic session-start bootstrap, skill
discovery/invocation, tool mapping, the acceptance test — and points at the
closest reference integration shape (shell-hook, in-process plugin,
instructions-file / declared context file) to copy. Covers discovery, build,
local install, tmux-driven verification, distribution, and PR submission, with a
live reference-integration index and a gotchas appendix.
Two non-negotiable rules: (1) never edit skill bodies; (2) everything ships
through the harness's own install mechanism — never edit the user's config. When
a plugin installer strips undeclared files, declare the bootstrap as a recognized
component (a manifest contextFileName-style context file the installer preserves
and the harness loads every session), generated at install time from the live
SKILL.md + tool mapping. Surfaced-skill-description bootstrap is the softer
fallback.
Hardened against real end-to-end ports (Antigravity CLI): shapes can compose; a
fork doesn't inherit its parent's behavior; a hook system != a usable
session-start event; verify @-includes AND context-file preservation with a
marker; web-search the docs and study existing plugins; reverse-engineer
undocumented harnesses; print/headless modes may hang; workspace-trust gates
stall tmux; declared context files survive plugin install while undeclared files
are stripped; skills-path registration is per-harness.
