Add OpenAccountants partner plugin (partner-built/openaccountants)

[michaelcutajar1995]

Summary

Adds OpenAccountants under partner-built/. It gives Claude verified tax & accounting skills for 190+ jurisdictions (every country + US state + Canadian province), with every answer linked to a named licensed accountant.

What it ships

• 11 MCP tools for discovery (start, list_jurisdictions, list_skills, list_verifiers), skill access (get_skill, get_skill_sections, search_skills), tax intelligence (get_rates, compare_jurisdictions), and the human handoff (request_accountant_review, submit_feedback)
• 882 verified skills kept current with annual rate refreshes, post-legislative updates, and IRS Revenue Procedure releases — so users don't get tax rates from training data that drifted two years ago
• Country-verified sign-offs by named licensed accountants. Michael Cutajar CPA for Malta; Werner Britz CA(SA) for South Africa; the network is growing
• 7 slash commands: /start, /return, /vat, /formation, /compare, /rates, /review

Why it's a fit for the marketplace

Anthropic's small-business/ and finance/ plugins surface a real gap: when the user is filing a real return or making a tax decision, they hit a "now talk to an accountant" wall. There's no path inside the AI for which accountant.

OpenAccountants closes that. The /review slash command captures the working paper Claude just produced, routes it to the named lead verifier for the user's jurisdiction, and returns a Calendly URL. The verifier sees the scenario + the worksheet before the call instead of walking in blind.

Trust model

• All 882 skills are open source at github.com/openaccountants/openaccountants — every rule, rate, and audit flash point is auditable
• Each jurisdiction has a named verifier with their credential published; tier 1 = signed, tier 2 = research-verified (flagged honestly in the output)
• Every skill output carries a provenance footer with the verifier name, skill slug, source URL, and a working-paper attribution line

Format

Mirrors the existing partner-built/apollo shape:

```
partner-built/openaccountants/
├── .claude-plugin/plugin.json
├── .mcp.json # http transport, openaccountants.com/api/mcp
├── LICENSE # MIT
├── README.md
├── commands/ # 7 slash commands
└── skills/openaccountants/SKILL.md
```

Companion marketplace

For users who want a plugin pre-scoped to one country or one topic, OpenAccountants also publishes openaccountants/marketplace — 83 specialised plugins (Malta, US-CA, UK, Germany, crypto, transfer pricing, SaaS vertical, etc.) all routing to the same hosted MCP backend. The plugin in this PR is the base / global entry point; the marketplace is the per-jurisdiction expansion.

Test plan

• claude plugin marketplace add anthropics/knowledge-work-plugins
• claude plugin install openaccountants@knowledge-work-plugins
• In Claude Code: ask "Help me prep a US Schedule C for 2025" — confirm the plugin loads the right skills via start and get_skill
• Confirm /openaccountants:review returns the named verifier (e.g. Michael Cutajar CPA for Malta, Werner Britz CA(SA) for South Africa) plus a Calendly URL
• Confirm working paper text passed to request_accountant_review lands server-side (admin dashboard at openaccountants.com)

Links

• Website: openaccountants.com
• Install (any AI client): openaccountants.com/connect
• Source: github.com/openaccountants/openaccountants
• Marketplace: github.com/openaccountants/marketplace

Happy to make any changes the maintainers want — scope of slash commands, README framing, MCP server expectations, anything.

[michaelcutajar1995]

@mattpic-ant @tobinsouth, quick context on why this might be especially relevant for the small-business/ users.

The Anthropic small-business plugin nails the QuickBooks/HubSpot/Docusign side of running an SMB (operations, finance basics, marketing). The wall a real US sole prop hits next is taxes (Schedule C/SE, 1099s, state nexus, quarterly estimated payments), and training-data rates drift fast (so when an LLM answers "what's my 2025 401k limit" it tends to give the 2023 number).

OpenAccountants slots in beside SMB cleanly (same MCP shape, same plugin shape, no overlap with what you've already got). When the small-business plugin says "have your accountant review", /openaccountants:review is what that line can actually call (it captures the working paper Claude produced, routes it to a named CPA for the user's jurisdiction, returns a Calendly link, so the user actually gets to a credentialed human instead of hitting a dead end).

Happy to do whatever makes this most useful (a small business-scoped subset of OpenAccountants, deeper integration with the existing finance/ skills in this repo, or just stay separate as a partner-built plugin, all on the table). Let me know what works.