Thai Legal Data API and MCP

Returns a Thai law section by number, the sections that govern a described situation, the Supreme Court rulings that interpret them, or a cited answer to a question.

GET/v3/store/data/thai-legal/section

+5 endpoints

Try it

• PriceFree
• Measured88.0%
• Served75.3Kcalls

• v1.0
• Active
• Benchmark paper (PDF)

Input

law

ประมวลกฎหมายอาญา

section

335

with_deka

true

OutputGET /v3/store/data/thai-legal/section

{
  "found": true,
  "law": "ประมวลกฎหมายอาญา",
  "section": "335",
  "unit": "มาตรา",
  "chapter": "หมวด ๑ ความผิดฐานลักทรัพย์และวิ่งราวทรัพย์",
  "in_force": "curated",
  "text": "ผู้ใดลักทรัพย์
(๑) ในเวลากลางคืน
...",
  "deka": [
    { "case_id": "600/2544", "year_be": 2544,
      "headnote": "เมื่อผู้เสียหายเห็นจำเลยทั้งสองกำลังลักเอามะม่วง...",
      "official_url": "https://deka.supremecourt.or.th" }
  ]
}

Every field, under ResponseOther endpoints: /meta, /laws, /search, /search, /ask see Request

Request

curl -X GET "https://api.iapp.co.th/v3/store/data/thai-legal/section?law=ประมวลกฎหมายอาญา&section=335&with_deka=true" \
  -H "apikey: YOUR_API_KEY"

Response

200OK. The fields are explained under Response.

{
  "found": true,
  "law": "ประมวลกฎหมายอาญา",
  "section": "335",
  "unit": "มาตรา",
  "chapter": "หมวด ๑ ความผิดฐานลักทรัพย์และวิ่งราวทรัพย์",
  "in_force": "curated",
  "text": "ผู้ใดลักทรัพย์
(๑) ในเวลากลางคืน
...",
  "deka": [
    { "case_id": "600/2544", "year_be": 2544,
      "headnote": "เมื่อผู้เสียหายเห็นจำเลยทั้งสองกำลังลักเอามะม่วง...",
      "official_url": "https://deka.supremecourt.or.th" }
  ]
}

Request

GET with query parameters, or POST with JSON where the table says so. 0.1 IC per request, free during the launch promotion; /meta and /laws are always free.

Headers

apikeystringrequired

Your API key, created under API Keys in the control panel.

Body

lawstringrequired

The law's name as /laws lists it, for /section: ประมวลกฎหมายอาญา.

sectionstringrequired

The section number, for /section: 335.

with_dekaboolean

true adds the Supreme Court decisions that cite the section.

querystring

A situation in plain Thai, for /search and /deka/search: "นายจ้างเลิกจ้างลูกจ้างต้องจ่ายค่าชดเชยเท่าไร".

cites_lawcites_sectionstring

For /deka/search: only rulings that cite this section, the law by its court abbreviation, ป.อ. and 335.

year_fromtop_kinteger

For the searches: rulings from this Buddhist-era year on, default 2540, since older rulings cite superseded numbering; and the number of results, 1 to 20, default 8 for sections and 5 for rulings.

questioninclude_dekastring, boolean

For /ask: the question in Thai, and whether to retrieve rulings as well as sections.

Endpoint	Does	Price
GET /v3/store/data/thai-legal/meta	What is indexed, and what is known to be missing	Free
GET …/laws, GET …/laws?law=	The catalogue of laws; a law's section numbers	Free
GET …/section	One section, verbatim	0.1 IC
GET or POST …/search	The sections that govern a situation, as 600-character snippets	0.1 IC
GET or POST …/deka/search	The rulings on a situation or a section, by headnote	0.1 IC
GET …/deka/{case_id}	One ruling, 1234/2565 or 1234-2565; include=body adds up to 4,000 characters	0.1 IC
POST …/ask	A grounded answer with citations	0.1 IC

Use it from an AI agent

Add the remote server https://mcp.iapp.co.th and sign in with your iApp account; there is no key to copy. In Claude, open Settings, Connectors, Add custom connector, name it iApp AI and paste the URL; in Claude Code, run claude mcp add --transport http iapp-ai https://mcp.iapp.co.th; the MCP server guide covers every other client. To run it locally, use uvx iapp-mcp with IAPP_API_KEY in the environment; the key stays on your machine. Tool calls are billed as the REST calls are.

Tool	Parameters	Does
iapp_thai_law_list	q	The catalogue, free; call it first for valid law names
iapp_thai_law_section	law, section, with_deka	The section's text
iapp_thai_law_search	query, top_k	Semantic search across the sections; warns when the governing law is not indexed
iapp_thai_deka_search	query, cites_law, cites_section, year_from, top_k	Precedent search
iapp_thai_deka_get	case_id, include_body	One ruling
iapp_thai_krisdika_opinion_search	query, top_k	Council of State opinions by subject line, linking the official PDF
iapp_thai_admincourt_search	query, court, top_k	Administrative Court decisions by subject, parties or case number, linking the official PDF
iapp_thai_legal_ask	question, include_deka	The grounded answer

Then ask in Thai: "ลักทรัพย์ในเวลากลางคืนมีโทษอย่างไร อ้างมาตราและฎีกาให้ด้วย", "หาฎีกาที่ตีความ ป.อ. มาตรา 335 หลังปี 2560".

Response

The panel shows /section; a field that appears only on some results says when.

in_forcestring

curated, in the 39-law consolidated core; repealed, marked ยกเลิก by krisdika, kept out of search but readable; unverified, everything else. There is deliberately no "in force" value, since an absent marker proves nothing: check that a section is still in force before relying on it.

citation_join

On a ruling from /deka/search: exact, range or none, how confidently it was linked to the section.

coverage

On a search whose governing law is not indexed: status: governing_law_not_indexed and the name of that law, instead of the closest thing held.

grounded

On /ask: false when nothing was retrieved, and then no answer. Every cited ฎีกา number is checked against what was retrieved; an unbacked citation gets one stricter regeneration, then a refusal.

depth

metadata_only on Council of State and Administrative Court results: their reasoning is in the linked PDF, so a hit is a pointer, never a holding.

foundboolean

false, with suggestions, for a section not held; still HTTP 200, so a client does not retry it.

lawstring

sectionstring

unitstring

chapterstring

textstring

The section, verbatim.

dekaarray

With with_deka: the rulings that cite the section, each with case_id, year_be, headnote and official_url.

A search below the confidence floor returns count: 0 and a confidence note rather than plausible filler.

Details

Measured

On the production service, 28 October 2026, against the public NitiBench benchmark of Thai financial and commercial law, searching all 2,346 laws the API holds.

Measure	Result
Governing section in the first 10 results, 3,729 short questions	88.0% (95% CI 87.0–89.1%)
Governing section first / in the first 5	58.4% / 84.3%
Answer sections in the first 10, 50 real Revenue Department rulings (131 sections)	22.1%; at least one found for 44.0%
Benchmark sections returned by /section	3,585 of 3,585
Sections amended since 2014 served in the amended wording	139 of 154 (the benchmark's own copy: 86)
Rulings returned with cites_section that cite that section	94.1% (443 of 471)
Median time through the API: /search / /section	0.88 s / 69 ms

A question about one provision usually finds its section on the first page of results; a long set of facts that turns on several provisions rarely finds all of them, so search once per issue. The benchmark covers financial and commercial law only: criminal, labour, land and administrative law were not measured, and /ask was not scored. Method, results by law and limits: the benchmark (PDF).

Limits

• Each account can make 5 requests a second, 100 a minute and 1,000 a day (the day starts at 00:00 UTC, 07:00 in Bangkok). A request over a limit returns 429, and the X-RateLimit-Remaining-Day header shows what is left of the day. The API answers questions one at a time: downloading the corpus in bulk is not permitted, and accounts that do so are suspended. For higher volume, contact sale@iapp.co.th.
• The ฎีกา corpus is not the whole Supreme Court archive; /meta reports what is indexed. Precedent search matches the headnote, not the narrative, and returns one entry per headnote, so the same ruling can appear more than once; group results by case_id.
• /section takes the law name exactly as /laws lists it and the section number in Arabic numerals, 335. Thai numerals (๓๓๕), the word มาตรา before the number, an abbreviation such as ป.พ.พ. or an act name without its year return found: false, even when the law is held.
• /deka/{case_id} does not accept joined case numbers such as 1579-1580/2558, which /deka/search can return; open those rulings from the link in the search result.
• 13 of 154 sections amended since 2014 are still served in their earlier wording, 12 of them family-law sections of the Civil and Commercial Code amended in 2024. Each such response carries a warning naming the amending act; read it before relying on the text.
• Council of State opinions and Administrative Court decisions are indexed at subject level only.
• Not legal advice. Verify a ruling at deka.supremecourt.or.th before relying on it; every result links there. Report an error to legal@iapp.co.th.

The corpus

• Statutes: 2,346 laws and 68,237 sections, พ.ศ. 2417 to 2569: the five codes, พ.ร.บ., พ.ร.ก., พ.ร.ฎ. and กฎกระทรวง; among them the 2560 constitution and labour, land, PDPA, computer, narcotics, traffic, social security, bankruptcy and intellectual property law.
• Curated core: 39 laws in consolidated text, the same used by OpenThai 2.0 Legal, preferred over any other copy.
• Supreme Court: 133,159 documents, 120,216 judgments plus orders and rulings, each with its headnote; 91,384 case numbers, since one ruling can hold several headnotes; 99.7% linked to the sections they cite.
• Council of State: 6,534 opinions, พ.ศ. 2466 to 2569.
• Administrative Court: 128,361 judgments and orders from all 16 courts, published under CC-BY.

Judgments and official reports are not copyright works under พ.ร.บ. ลิขสิทธิ์ พ.ศ. 2537 มาตรา 7(4), so the text is public domain; iApp does not certify it on the court's behalf.

Data handling

Queries are processed in memory and not kept after the response. Consent and notice under PDPA and GDPR remain with you as the data controller.