7.8 KiB
Codex Plugin Marketplace Support for Reliquary
Date: 2026-05-30
Summary
Reliquary is already a Claude plugin marketplace, and the current Codex installation can consume it today through the existing .claude-plugin/marketplace.json layout. In the local Codex CLI 0.135.0-alpha.1 environment, the reliquary marketplace is configured from git@git.g4b.org:dirigence/reliquary.git, and g4b_ai, gitea, and project-uv are installed and enabled.
For long-term portability, Reliquary should publish a parallel Codex-native marketplace layout instead of relying on Codex's compatibility with Claude marketplace metadata. The practical target is:
- keep
.claude-plugin/marketplace.jsonfor Claude Code - add
.agents/plugins/marketplace.jsonfor Codex - keep each plugin's existing
.claude-plugin/plugin.json - add each plugin's
.codex-plugin/plugin.json - keep shared skill content under
plugins/<plugin>/skills/<skill>/SKILL.md
The skill directories can remain shared between Claude and Codex. The main work is metadata and install documentation.
Current Repository State
The repo root currently has:
.claude/settings.json, which configures Claude to know thereliquarymarketplace and enable selected plugins..claude-plugin/marketplace.json, which declares the marketplace and four plugins:g4b_ai,dioxus,project-uv, andgitea.plugins/<plugin>/.claude-plugin/plugin.jsonforg4b_ai,gitea, andproject-uv.- shared skills under
plugins/<plugin>/skills/.../SKILL.md.
The repo-level CLAUDE.md already tells Claude users that this repo is a marketplace and that workpad material lives under docs/workpad/.
Observed Codex Behavior
Codex is already configured locally with:
[marketplaces.reliquary]
source_type = "git"
source = "git@git.g4b.org:dirigence/reliquary.git"
[plugins."g4b_ai@reliquary"]
enabled = true
[plugins."gitea@reliquary"]
enabled = true
[plugins."project-uv@reliquary"]
enabled = true
Running the local Codex binary's plugin listing showed:
Marketplace `reliquary`
g4b_ai@reliquary installed, enabled 0.1.0
dioxus@reliquary not installed
project-uv@reliquary installed, enabled 0.1.0
gitea@reliquary installed, enabled 0.1.0
That proves Codex can currently discover this repo's Claude marketplace file. However, Codex's own plugin creation guidance uses .codex-plugin/plugin.json for plugin manifests and .agents/plugins/marketplace.json for marketplace files, so Reliquary should add those files explicitly rather than treating Claude metadata as the only source of truth.
Codex-Native Marketplace Shape
OpenAI's Codex plugin creator skill describes Codex plugin scaffolds as containing a required .codex-plugin/plugin.json, optional skills/, and marketplace entries in .agents/plugins/marketplace.json. Its reference schema shows skills: "./skills/" in the plugin manifest and Codex marketplace entries with source, policy, and category fields.
Recommended repo-level Codex marketplace file:
.agents/plugins/marketplace.json
Recommended shape:
{
"name": "reliquary",
"interface": {
"displayName": "Reliquary"
},
"plugins": [
{
"name": "g4b_ai",
"source": {
"source": "local",
"path": "./plugins/g4b_ai"
},
"policy": {
"installation": "AVAILABLE",
"authentication": "ON_INSTALL"
},
"category": "Productivity"
}
]
}
Each current plugin should get a Codex manifest:
plugins/g4b_ai/.codex-plugin/plugin.json
plugins/gitea/.codex-plugin/plugin.json
plugins/project-uv/.codex-plugin/plugin.json
plugins/dioxus/.codex-plugin/plugin.json
Recommended minimal manifest shape:
{
"name": "g4b_ai",
"version": "0.1.0",
"description": "Gabor's personal Codex skills: workpad, research-tree, implementation-orchestration, markdown-embedded-svg.",
"author": {
"name": "Gabor Körber",
"email": "gab@g4b.org"
},
"skills": "./skills/",
"interface": {
"displayName": "g4b_ai",
"shortDescription": "Personal project workflow skills for Codex.",
"longDescription": "Workpad placement, research orchestration, implementation orchestration, and Markdown SVG guidance.",
"developerName": "Gabor Körber",
"category": "Productivity",
"capabilities": ["Skills"]
}
}
The existing .claude-plugin/plugin.json files can stay as-is. The .codex-plugin files can point at the same skills/ folders.
How Users Would Install from Codex
Once the Codex marketplace file exists, a Codex user can add this marketplace from the repo:
codex plugin marketplace add git@git.g4b.org:dirigence/reliquary.git
Then install the desired plugin:
codex plugin add g4b_ai@reliquary
For local development from a checked-out repo, Codex also supports local marketplace sources:
codex plugin marketplace add G:\dev\projects\reliquary
codex plugin add g4b_ai@reliquary
The local Codex help confirms the relevant command forms:
codex plugin marketplace add <SOURCE>codex plugin marketplace listcodex plugin marketplace upgradecodex plugin add PLUGIN@MARKETPLACEcodex plugin list
Using Workpad from Codex Projects
The workpad skill should remain inside the g4b_ai plugin:
plugins/g4b_ai/skills/workpad/SKILL.md
For any Codex project that wants to use it, install and enable g4b_ai@reliquary, then add project-level AGENTS.md instructions similar to:
# Project Instructions
Working documents live in `docs/workpad/`.
Use the `g4b_ai:workpad` skill for plans, research notes, specs, journals, reports, goals, and brainstorms.
This gives Codex both pieces it needs:
- the installed plugin supplies the actual
workpadskill AGENTS.mdsupplies the project-specific workpad location and policy
For projects that do not already have docs/workpad/, the workpad skill can decide placement using its own rules. In this repository, docs/workpad/ already exists and should remain the canonical location.
Recommended Changes to Reliquary
- Add
.agents/plugins/marketplace.json. - Add
.codex-plugin/plugin.jsonto each plugin directory. - Update the root
README.mdwith separate Claude and Codex installation sections. - Add a short
AGENTS.mdat the repo root for Codex-specific repo instructions, mirroring the important parts ofCLAUDE.md. - Add a validation note or script so marketplace updates keep Claude and Codex plugin lists in sync.
The Codex marketplace should include all plugins currently listed in .claude-plugin/marketplace.json: g4b_ai, dioxus, project-uv, and gitea.
Compatibility Notes
Codex can currently consume the Claude marketplace layout in this environment, but that is an implementation detail from the user's perspective. The repo should publish Codex-native metadata so future Codex versions, Codex app UI flows, and third-party tooling can rely on the expected Codex structure.
Codex plugin cache behavior is version-sensitive. During local plugin development, Codex's own update guidance recommends changing the plugin version with a Codex cachebuster suffix, reinstalling the plugin, and starting a new thread so the new skills and tools are loaded.
Sources
- OpenAI Codex plugin creator skill: https://github.com/openai/codex/blob/main/codex-rs/skills/src/assets/samples/plugin-creator/SKILL.md
- OpenAI Codex plugin and marketplace JSON reference: https://raw.githubusercontent.com/openai/codex/main/codex-rs/skills/src/assets/samples/plugin-creator/references/plugin-json-spec.md
- OpenAI Codex local plugin update reference: https://raw.githubusercontent.com/openai/codex/main/codex-rs/skills/src/assets/samples/plugin-creator/references/installing-and-updating.md
- Local verification in this repo with Codex CLI 0.135.0-alpha.1.