Package a plugin payload

The archive is host-specific, not portable

There is one archive per host, built from one plugins/<host>/<plugin>/ payload. Never treat a built archive as a generic "OpenDesign plugin zip" and never hand a Codex archive to another host. The payload's own contents are host conventions:

Payload member	Why it is host-specific
.codex-plugin/plugin.json	The manifest directory name is Codex's convention. Another host reads a different directory.
open-design.package.json	Declares schemaVersion: "open-design-codex-cloud-package/v3" and minimumCodexCliVersion.
skills/<skill>/agents/openai.yaml	Per-skill interface metadata keyed by host. A different host reads a different filename in agents/.

The repository layout encodes the same rule: plugins/<host>/<plugin-name>/, described under "Host directory convention" in AGENTS.md. Codex is the only validated host in this revision.

The host-neutral parts — README.md, SKILL.md, assets/ — are shared content, not a shared package. They only become installable once wrapped in one host's manifest.

Build it

node scripts/package-plugin.mjs

--host defaults to codex, the only host with packaging rules. Useful flags:

• --host <name> — pick a different host payload.
• --plugin <name> — required only when plugins/<host>/ holds more than one plugin.
• --out-dir <path> — archive destination; defaults to .tmp/plugin-upload (gitignored).
• --skip-gates — skip the validator and package tests. Use only for a throwaway inspection build, never for one you intend to upload.
• --json — machine-readable result, including the archive sha256.

The archive lands at .tmp/plugin-upload/<plugin>-plugin-<version>.zip for Codex. That filename has no host token because 0.5.2 was submitted to the Portal under it and submission records should stay continuous; every host added later gets <plugin>-<host>-plugin-<version>.zip instead.

What the script refuses to do

Each of these is a real failure mode that would otherwise ship a broken or mislabelled archive, so treat a rejection as a bug in the payload, not as an obstacle to work around:

• Unknown host. A host with no entry in the script's HOSTS table is rejected rather than packaged with guessed conventions.
• Foreign interface file. A Codex payload carrying agents/claude.yaml (or any non-openai.yaml interface) is rejected — that is exactly the cross-host leak this split exists to prevent.
• Wrong package contract. A payload whose *.package.json declares another host's schemaVersion.
• Stale provenance. release-manifest.json plugin.contentListSha256, plugin.version, or plugin.path disagreeing with the payload on disk. This is the common one: someone edited the payload and forgot to regenerate the digest. The error prints the regeneration command.
• OS junk or symlinks. .DS_Store, __MACOSX/, Thumbs.db, desktop.ini, or any symlink inside the payload.

Unless --skip-gates is passed, it also runs scripts/validate-distribution.mjs and tests/distribution-contract.test.mjs first, and reports their results.

Reproducibility

The same reviewed tree always produces the same archive bytes. Entries are emitted in a fixed C-collation order, zip -X drops platform extra fields, and staged mtimes are normalized to release-manifest.json's generatedAt with TZ=UTC. Two consecutive runs must yield the same sha256; if they do not, something is writing into the payload between runs — find it before uploading.

Record the printed archive sha256 alongside the submission so the uploaded bytes can be re-derived later.

Adding a new host

Do not package a host by loosening a check. Add its entry to HOSTS in scripts/package-plugin.mjs with all of:

• manifestPath — where that host reads the plugin manifest.
• packageContractSchema — the schemaVersion its package contract must declare.
• agentInterfaceFile — the filename it reads inside each skill's agents/.

Then create the validated payload at plugins/<host>/<plugin>/, extend scripts/validate-distribution.mjs and tests/distribution-contract.test.mjs to cover it, and only then build. AGENTS.md requires a validated host-specific package before a host directory is added at all.

After the archive exists

The archive is a Portal upload artifact only. It is not the normal user installation route — users install through the Git marketplace (codex plugin marketplace add nexu-io/open-design-agent-plugins), which reads plugins/codex/open-design/ from main directly and never touches this zip.

The reverse substitution fails too: a GitHub source download ("Download ZIP", or a repository/PR archive) is not an upload artifact. It nests the manifest under <archive>/plugins/<host>/<plugin>/, and the Portal requires it at the archive root. If someone reports "Plugin manifest not found", check which file they uploaded before looking at the payload.

Before submitting, confirm the reviewer-facing records match the version you just built: docs/SUBMISSION_TEST_CASES.md, and the validation block in release-manifest.json (entries marked not-rerun-for-<version> still refer to an older candidate and must be re-run against the Portal's own validators).