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Thai Legal Data API/MCP — give Claude, ChatGPT, Grok & Gemini precise Thai law (4× more accurate citations)

· 4 min read
Kobkrit Viriyayudhakorn
Kobkrit Viriyayudhakorn
CEO @ iApp Technology

Thai Legal Data API/MCP

Thai law, as data — not prose. The new Thai Legal Data API/MCP lets you look up any มาตรา verbatim, search 39 Thai laws by meaning, find the Supreme Court decisions (ฎีกา) that interpret a specific section, and ask legal questions that are answered only from retrieved sources — with every citation machine-checked. The API never invents a case number — and it plugs straight into Claude, ChatGPT, Grok, or any assistant that speaks MCP.

What's inside​

  • 39 laws · 6,363 sections — the consolidated statute corpus behind OpenThai 2.0 Legal (ป.พ.พ., ป.อ., ป.วิ.พ., ป.วิ.อ., ประมวลรัษฎากร and more)
  • 70,634 Supreme Court rulings with their หลักกฎหมาย (legal-principle) headnotes
  • 99.7% citation-linked — go from a section straight to the case law that interprets it
  • Every result links back to the official record at deka.supremecourt.or.th

We measured it: Claude gets 4× more accurate​

Does giving an AI assistant real Thai legal data actually help? We benchmarked it: 25 questions from the nitibench-CCL legal QA dataset, answered by the same Claude model twice — once bare, once with the six iapp-mcp legal tools.

Bare ClaudeClaude + iapp-mcp
Cites the correct มาตรา20%80%
Citation F10.0930.380

4× more correct citations (claude-sonnet-5, n=25, gold-citation hit rate). Without tools, the model cites plausible neighbors — มาตรา 298 or 300 when the right answer is 299. With tools, it retrieves the real section text and cites 299 exactly. Even our strongest test model improved by 1.5× — and with the tools, every model we tested converged at ~80% accuracy.

Real-world use cases​

** Lawyers — precedent research in minutes, not afternoons**

"Find ฎีกา interpreting ป.อ. 335 (11) on employees taking employer property — and where the line between theft and embezzlement falls."

Real rulings grouped by issue, each with its legal-principle headnote and a verification link.

** Law students — exam prep with exact statute text**

"Give me ป.พ.พ. section 420 verbatim, the elements of tort liability, and the landmark ฎีกา worth memorizing."

The text matches the code letter-for-letter — not an AI's misremembered version.

** In-house legal & compliance — cited answers for internal memos**

"We store customer ID-card copies without consent — which sections does that violate, and is there precedent?"

** Developers — build legal apps without building the corpus** Call the REST endpoints (/section, /search, /deka/search, /ask) or plug the MCP into your agent — 6,363 sections and 70,634 rulings become your app's foundation with zero scraping or data maintenance.

** Everyone else — everyday legal questions**

"Someone defamed me on Facebook — which section applies and what's the limitation period?"

Answers cite real sections and precedent — solid preparation before you talk to an actual lawyer.

Connect it in one URL — no API key to paste​

The new remote MCP server connects with your iApp account through OAuth — sign in once and your API key is linked automatically, never copied anywhere:

https://mcp.iapp.co.th
  • Claude (claude.ai / Desktop): Settings → Connectors → Add custom connector → paste the URL → Connect
  • Antigravity (Gemini): Agent panel → MCP servers → add { "iapp-ai": { "serverUrl": "https://mcp.iapp.co.th" } }
  • Claude Code: claude mcp add --transport http iapp-ai https://mcp.iapp.co.th
  • Cursor / Codex / Windsurf and any MCP client: same URL — see the per-client setup guide

Then just ask in Thai: "หาฎีกาที่ตีความ ป.อ. มาตรา 335 หลังปี 2560".

Prefer the classic local install? claude mcp add iapp-mcp -s user -e IAPP_API_KEY=YOUR_API_KEY -- uvx iapp-mcp — all six legal tools ship in iapp-mcp 2.1.0.

Prefer REST? GET /v3/store/data/thai-legal/section?law=ประมวลกฎหมายอาญา&section=335&with_deka=true — see the full documentation with live try-it demos.

Free during launch​

All endpoints are free during the launch promotion (then 0.1 IC/request; /meta and /laws stay free forever). New accounts get 50 IC free — no credit card required.

Try it now →

For research use — not legal advice. Every result carries a link to the official Supreme Court record; verify there before relying on a ruling in practice.