Cross-harness capability matrix

claude-agents is a multi-harness plugin marketplace. Source-of-truth lives under plugins/ as Claude Code markdown. Per-harness artifacts are generated by adapters under tools/adapters/. Use it to ground design choices in named patterns, trade-offs and examples.

Editorial note: curated source snapshot published by Collider.club under the MIT License. Source attribution is preserved in the front matter.

Source snapshot

Cross-harness capability matrix

claude-agents is a multi-harness plugin marketplace. Source-of-truth lives under plugins/ as Claude Code markdown. Per-harness artifacts are generated by adapters under tools/adapters/.

This file mirrors the capability matrix in tools/adapters/capabilities.py. Edit there; regenerate via make docs.

Supported harnesses

Capability matrix

Claude Code native features

Claude Code is the source-of-truth harness. It reads the canonical context file via CLAUDE.md, a symlink to AGENTS.md. Features it supports that other harnesses degrade or lack:

• Per-agent tool allowlist — tools: frontmatter honored verbatim (Cursor / Codex are coarser; the OpenCode adapter translates this into a permission: block).
• Task / Agent spawn tool — fan-out parallel subagent execution. (Codex requires naming an agent in prose to delegate.)
• TodoWrite — native progress tracking. (Not available in Codex / Cursor / Gemini.)
• Slash-command marketplace — full /plugin install, /plugin marketplace workflow.

Claude-Code-only paths:

• .claude-plugin/marketplace.json — plugin registry (source of truth)
• plugins/<name>/.claude-plugin/plugin.json — per-plugin manifest

Graceful degradation

Each adapter handles incompatibilities mechanically — authors don't need to know the per-harness rules to write portable content.

Output paths (committed vs gitignored)

Native install is lean: only small JSON registries (pointing at the source plugins/) are committed. The large transformed skill/agent trees stay gitignored — regenerate them locally.

Committed:

.claude-plugin/marketplace.json        # SOURCE OF TRUTH
plugins/                               # SOURCE OF TRUTH
AGENTS.md                              # canonical context file
.agents/plugins/marketplace.json       # Codex marketplace registry (source.path: ./plugins/<name>)
plugins/*/.codex-plugin/plugin.json    # per-plugin Codex manifest (skills: ./skills/)
.cursor-plugin/, .cursor/rules/        # Cursor marketplace + curated rules (point at source)
gemini-extension.json                  # Gemini extension manifest (contextFileName: AGENTS.md)

Gitignored (regenerate with make generate):

.codex/skills/, .codex/agents/         # transformed Codex trees (for ~/.codex/skills symlink recipe)
.opencode/agents/, .opencode/commands/, .opencode/skills/, opencode.json
skills/, agents/, commands/            # Gemini trees at extension root (not for OpenCode install)
.copilot/agents/, .copilot/skills/, .copilot/commands/

Native install

• Codex — npx codex-marketplace add wshobson/agents (or it's auto-discovered as a project marketplace when the repo is the cwd), then install individual plugins. Codex reads SKILL.md straight from plugins/<name>/skills/; skills over the 8 KB cap are truncated by Codex at load. The gitignored .codex/skills/ copies remain for the ~/.codex/skills symlink recipe.
• Cursor — add the marketplace, then /plugin install <name>. Entries point at source ./plugins/<name>; Cursor reads SKILL.md + .md agents from source directly.
• Gemini — no one-step-from-URL install (the lean tradeoff). Clone the repo, then make generate HARNESS=gemini and gemini extensions install . (local path).
• OpenCode — no one-step-from-URL install. Clone the repo, then make install-opencode (runs generate + symlinks .opencode/ → ~/.config/opencode/).

Regenerating

The committed registries point at source; the transformed trees are regenerated on demand. Contributors must run make generate-all before committing source changes — CI fails on drift of the committed registries.

make generate HARNESS=codex
make generate HARNESS=cursor
make generate HARNESS=opencode
make generate HARNESS=gemini
# Or all at once (run before committing source changes):
make generate-all

# Optional global OpenCode install:
make install-opencode
make uninstall-opencode

External Pensyve integrations

The Claude Code marketplace includes Pensyve as an external git-subdir plugin. For generated harnesses, use Pensyve's upstream harness-native integration:

Global install

OpenCode and Copilot support installing generated artifacts globally for user-level discovery:

make install-opencode    # symlink .opencode/ → ~/.config/opencode/
make uninstall-opencode

make install-copilot     # symlink .copilot/ → ~/.copilot/
make uninstall-copilot

# Force-replace conflicting symlinks:
make install-copilot FORCE=1

Copilot discovers agents from .copilot/agents/ and skills from .copilot/skills/ at the repo level, and from ~/.copilot/agents/ and ~/.copilot/skills/ at the user level. The adapter emits to .copilot/; use make install-copilot for user-level discovery.

See also

• authoring.md — portable-content style guide for plugin authors
• architecture.md — overall design principles
• plugin-eval.md — the harness_portability scoring dimension

About Collider.club

This card belongs to the curated knowledge base of Collider.club — a closed business club for entrepreneurs, engineers, investors and domain experts building projects for international markets. Members work across DeFi, AI/ML, FinTech, Web3, banking, hardware and venture capital, and the club runs closed sessions on high-margin niches with anonymous speakers.

• Club: https://collider.club
• Collection: Collider.club curated card library (mdrss-card/v2)
• Maintainer: Collider.club editorial team

License

MIT License — Copyright (c) 2026 Collider.club. Full text: LICENSE · https://opensource.org/licenses/MIT