Multi-Harness Agentic Plugin Marketplace — 84 Plugins, 192 Agents, 6 Harnesses From One Source

TL;DR

The wshobson/agents repository (36.7K stars, 4K forks) is a multi-harness agentic plugin marketplace — 84 plugins, 192 agents, 156 skills, and 102 commands built for Claude Code as the source of truth, then generated natively for OpenAI Codex CLI, Cursor, OpenCode, Gemini CLI, and GitHub Copilot. One plugins/ directory, six harness adapters, zero lowest-common-denominator translations.


The Cross-Harness Problem

By mid-2026, the AI coding agent landscape had fragmented into at least six serious harnesses. Claude Code, Codex CLI, Cursor, GitHub Copilot, Gemini CLI, and OpenCode each have their own plugin formats, skill manifests, agent definitions, and command registries. Teams that want portability face a stark choice: maintain six separate plugin repos, or accept lock-in to a single harness.

The wshobson/agents project solves this with a generative adapter pattern — one Markdown source, six native outputs [1].


What’s Inside

Component Count Purpose
Plugins 84 Granular, single-purpose installable units (82 local + 2 external via git-subdir)
Agents 192 Domain experts (architecture, languages, infra, security, data, ML, docs, business, SEO)
Skills 156 Modular knowledge packages with progressive disclosure
Commands 102 Slash commands: scaffolding, security scans, test gen, infrastructure setup
Orchestrators 16 Multi-agent coordination workflows (full-stack, security, ML, incident response)

Each plugin is isolated and composable. Installing a plugin loads only its components into context — not the entire marketplace. A python-development plugin might contain 3 agents, 1 command, and 16 skills, scoped to Python workflows only [1].


Architecture: Single Source, Native Output

The core innovation is the adapter generator pattern. The source of truth lives in plugins/ as Claude Code-native marketplace.json + plugin definitions. A make generate-all command produces harness-specific artifacts:

Harness Generated Output Notes
Claude Code marketplace.json + plugins/ (source of truth) Native format
Codex CLI .agents/plugins/marketplace.json + plugins/*/.codex-plugin/plugin.json (committed); .codex/skills/, .codex/agents/ (gitignored) 8 KB skill cap respected; commands mapped to skills
Cursor .cursor-plugin/, .cursor/rules/ Thin marketplace + curated rules; reuses .claude/
OpenCode .opencode/agents/, .opencode/commands/, .opencode/skills/ permission: block from tools: allowlist
Gemini CLI skills/, agents/, commands/ (TOML) Native skills + subagents per April 2026 spec
GitHub Copilot .copilot/agents/, .copilot/skills/, .copilot/commands/ Markdown agent profiles; model maps to native Claude

This is not a translation layer — each generator produces idiomatic artifacts for its target harness. The Codex CLI output respects the 8 KB skill file cap, OpenCode gets permission: blocks from tools: allowlists, and Gemini CLI gets TOML-format subagent definitions [1].


Model Tiers

The marketplace ships with a tiered model strategy that routes tasks to the right model by complexity:

Tier Model Use Case
0 Fable 5 Longest-horizon autonomous work — large migrations, multi-hour runs (opt-in, premium cost)
1 Opus Architecture, security, code review, production-critical
2 inherit User-chosen — backend, frontend, AI/ML, specialized
3 Sonnet Docs, testing, debugging, API references
4 Haiku Fast operational tasks, SEO, deployment, content

Model aliases are refreshed June 2026 (Claude Fable 5 support added; Codex, Copilot, and OpenCode maps updated) [1].


Quick Start Setup

Claude Code (source of truth)

/plugin marketplace add wshobson/agents
/plugin install python-development

Any of the 84 plugins can be installed the same way. The marketplace is auto-discovered from the committed marketplace.json.

Codex CLI and Cursor

npx codex-marketplace add wshobson/agents
# Cursor: add the marketplace, then /plugin install <name>

Both read from committed registries in the repo.

Gemini CLI and OpenCode

gh repo clone wshobson/agents ~/agents && cd ~/agents
make generate HARNESS=gemini && gemini extensions install .
make install-opencode

The clone + generate pattern produces harness-native artifacts without manual translation [1].


Quality Framework

The project includes plugin-eval, a three-layer evaluation system:

  1. Static analysis — deterministic structural checks (<2s, free)
  2. LLM Judge — semantic evaluation across 4 dimensions (~30s, using Haiku + Sonnet)
  3. Monte Carlo — statistical reliability via 50-100 simulated runs (~2-5 min)
uv run plugin-eval score path/to/skill --depth quick
uv run plugin-eval certify path/to/skill

The build pipeline also includes make validate for structural integrity and make garden for drift and dead-link detection [1].


Why This Matters for the Agent Ecosystem

Cross-harness portability is the next frontier for AI coding agents. The 2025 era of “pick one harness and build everything in it” is giving way to a multi-harness workflow where developers use Claude Code for architecture, Codex CLI for rapid iteration, and Cursor for in-editor polish — all pulling from the same skills and agent definitions [2][3].

The Firecrawl 2026 coding agent comparison notes that the frontier models have converged, so “the agent wrapper now decides your experience” [2]. When the models are largely interchangeable, the value shifts to the ecosystem of plugins, skills, and agents that surround them. A project like wshobson/agents makes that ecosystem portable.

The Agensi 2026 comparison confirms that all major agents now support SKILL.md, making skill portability a reality [3]. The wshobson/agents project extends this principle from individual skills to entire plugin marketplaces.



References

[1] wshobson/agents — Multi-harness agentic plugin marketplace. GitHub. https://github.com/wshobson/agents

[2] Hiba Fathima, “Best AI Coding Agents in 2026: Harness, Cost, and Accuracy Compared.” Firecrawl Blog, June 2026. https://www.firecrawl.dev/blog/best-ai-coding-agents

[3] “Claude Code vs Cursor vs Codex CLI Compared (2026).” Agensi.io. https://www.agensi.io/learn/ai-coding-tools-comparison-2026

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