OpenCaseLaw — Swiss Caselaw, Statutes & Doctrine

Year-by-year decision counts showing jurisprudence evolution. Use with a statute reference (law_code + article), a text query, or both. Returns yearly counts with visual bar chart.

MANDATORY FINAL-STEP AUDIT of your draft answer. Checks five hallucination classes: (1) every case citation (BGE/BGer/BVGer/BStGer/BPatGer/MKGE and FR/IT forms) exists in the corpus and any pinpoint (E. X.Y / consid. X.Y) resolves to a real Erwägung; (2) every 'Art. X LAW' statute reference resolves (known abbreviation, existing article); (3) every quoted passage of 30+ chars appears verbatim in a cited source; (4) decision dates adjacent to citations match the stored dates; (5) with audit_grounding=true, an independent LLM judge checks that each cited source actually supports the claim sentence preceding it (one call, ~3 s, regardless of citation count). Returns the draft annotated per citation plus a structured issues list. CALL THIS BEFORE emitting any answer containing a case citation, statute reference or direct quotation; set audit_grounding=true for answers with 2+ citations. If ok=false, fix each issue; if ok=true, send linked_text verbatim.

Browse recent legislation changes for a canton or federal level. Shows new laws, amendments, and abrogations with dates.

Verify whether a Swiss court decision actually supports a legal claim. Uses an independent Sonnet judge to compare the claim against verbatim text from the decision (Erwägung if pinpoint given, else Regeste, else first portion of full text). Returns {supports: yes|partial|no|contradicts|unrelated, confidence, supporting_excerpt, qualifying_excerpt, reasoning}. CALL THIS for any claim where citing the wrong authority would mislead the user — especially when paraphrasing a decision or drawing a proposition from a complex Erwägung. If supports=no or contradicts, do NOT use the cited decision for that claim.

Get the canonical Swiss citation string for a decision reference. CALL THIS BEFORE writing any case citation in your response. Returns ready-to-embed citation_string (DE/FR/IT variants plus a canonical URL) and a verbatim rule_statement. If the reference doesn't exist, returns exists=false plus close_matches for typo-correction — DO NOT guess or construct citations yourself; if you get exists=false, either re-query with a close match or skip the citation entirely. Accepts any Swiss reference form: decision_id (bger_4A_747_2012), BGE reference (BGE 140 III 86), or docket number (4A_747/2012). Optional pinpoint ('2.3') generates the Erwägung-anchored citation and URL.

Build a research-only mock decision outline from user facts. Combines relevant Swiss case law retrieval with statute references. If possible, enriches statutes with Fedlex text excerpts. IMPORTANT: The tool may return clarification questions (high/medium priority). High-priority clarifications must be answered (via the clarifications parameter) before the tool will provide a conclusion. Call again with clarifications to get the full analysis.

ChatGPT Deep Research compatibility tool. Fetches one Swiss decision's full text by id, returning {id, title, text, url, metadata}. The id comes from a `search` result (a decision_id like bger_6B_1234_2025; a docket number or BGE reference also resolves). General clients should prefer `get_decision`.

Trace the appeal chain (Instanzenzug) for a decision. Shows prior instances (lower courts) and subsequent instances (appeals to higher courts). Reconstructs the full procedural path, e.g. Bezirksgericht → Obergericht → Bundesgericht. Uses the is_prior_instance flag from decision headers.

Given a decision_id, show what it cites and what cites it. Uses the reference graph database with 9.65M citation edges. Returns resolved citations with confidence scores and unresolved references.

Find the most-cited decisions for a topic or statute. Authority ranking based on citation graph. Filter by statute (law_code + article), topic query, court, and date range. Top-3 results auto-attach a `pinpoint` field {e_number, matched_sentence, confidence, url, score, source} anchoring the most-relevant Erwägung — see system instructions U3 for how to surface it. Each result also carries citation_string_{de,fr,it} + canonical_url + is_leading_case + citation_count for ready-to-quote Swiss-format citations.

Find which Erwägung paragraph(s) match a legal claim. Server-side FTS5+BM25 over per-paragraph text; returns top-k with confidence labels (high/medium/low) and a highlighted_snippet wrapping the matched sentence in <mark>…</mark> (quote it verbatim). When no_match=true or confidence=low, do NOT cite any Erwägung — report no_match. Federal decisions only. Replaces the 'always-E.-3.1' guessing pattern.

Find OA legal scholarship that cites a specific Swiss court decision. Reverse direction of the scholarship↔caselaw bridge: given a decision_id (e.g. 'bge_BGE_140_III_86' or 'bger_4A_571_2008'), return open-access publications that cite it in their full text. Citations are extracted deterministically by regex + lookup against the canonical decision corpus, so resolved citations are always to decisions we hold.

Find OA legal scholarship that cites a given Swiss statute article. Sourced from article-anchored commentaries (OnlineKommentar / OpenLegalCommentary) PLUS full-text citation extraction across the open-access journal corpus (~90k statute references resolved from 9k full-text records).

Generate a Swiss law exam practice question (Fallbearbeitung) based on a real BGE. Returns a fact pattern (Sachverhalt) from a real court decision and a hidden analysis (applicable statutes, leading case, legal test, correct outcome). Workflow: present the fact_pattern and hint to the student, wait for their analysis, then reveal the analysis field and compare. The student can then call get_case_brief(source_decision_id) to study the full case. Pass exclude_ids from previous calls to avoid repeating the same case.

Chronological story of a single statute article: current text + every linked Botschaft (enacted + amendments) + leading court interpretations + doctrinal commentary, all ordered by date. Combines statutes.db, materialien.db, reference_graph.db, and ok_commentaries.db into one timeline. USE THIS when the user asks 'how did Art. X evolve' or 'what's the full picture on Art. X' — a single call returns the legislative + judicial + doctrinal arc.

Return verbatim text from the Federal Council Botschaft (or Erläuterungsbericht) explaining the legislative purpose of a specific article. Joins the verbatim Botschaft corpus (post-2003 BBl publications, Akoma Ntoso XML where available, PDF fallback otherwise) with the article-Botschaft link table. Returns one entry per source — original Botschaft + any amendment Botschaften. All paragraphs are verbatim text the LLM can quote with `bbl_citation, S. {page}` references. USE THIS when the user asks 'what was the purpose of Art. X' or 'what did Parliament intend' or 'why does Art. X exist'. Coverage is rolling — empty `sources` means the verbatim corpus hasn't ingested that article's Botschaft yet; fall back to get_doctrine for the digest layer.

Structured case brief: regeste, Sachverhalt, key Erwägungen (first 12 only — for orientation, NOT a pinpoint ranking), Dispositiv, statutes, citation authority, related cases. Accepts BGE ref, decision_id, or docket. To pinpoint which Erwägung supports a specific claim, use find_relevant_erwaegung — never guess from key_erwaegungen alone.

Look up a scholarly legal commentary from OnlineKommentar.ch (CC-BY-4.0) for a Swiss federal law article. Without article: lists available commentaries for that law. With article: returns the full commentary text, authors, and citation. Covers 19 Swiss laws including BV, OR, ZGB, StGB, StPO, ZPO, DSG, SchKG, and more.

Fetch a single court decision with full text. Look up by decision_id (e.g., bger_6B_1234_2025), docket number (e.g., 6B_1234/2025), or partial match. Full text is truncated at 200,000 characters for very long decisions. Set full_text=false to get only metadata and regeste.

Structured decision fields: Sachverhalt (facts), Erwägungen as numbered paragraphs ('1', '1.1', '2.3'), Dispositiv (ruling), Regeste (BGE only). Federal decisions only; for cantonal use get_decision. Returns excerpts; for verbatim full text of one Erwägung, use get_erwaegung. PINPOINT POLICY: never guess. If user gave an e_number → verify with get_erwaegung. If user gave only a claim → use find_relevant_erwaegung (FTS5+BM25 with confidence labels). If neither is confident, report no_match — do NOT default to E. 3.1.

Use this tool to fetch SEVERAL decisions at once (1-10 ids) instead of calling get_decision repeatedly. Same data per decision — canonical citation strings, Markdown link, Regeste, metadata — in ONE call. Prefer this whenever you are about to read more than one decision from a search result: it is the difference between one tool call and ten, which matters because clients cap tool calls per turn. full_text defaults to FALSE here (unlike get_decision) because ten full judgments exceed connector response limits; set it true only for a short id list, and each text is excerpted with the cut disclosed. Ids not found are reported individually — the rest of the batch still returns.

Get statute text + leading cases + doctrinal timeline + Federal Council Botschaft (legislative intent) + scholarly commentary for a Swiss law article or legal concept. ALWAYS USE THIS for questions about the purpose, intent, or ratio legis of a provision — it returns the Botschaft (Materialien) alongside the case law. Input: statute reference ('Art. 41 OR', 'Art. 8 BV') or legal concept. Returns: current statute text, top 5-8 BGEs ranked by citation authority with the rule each establishes, doctrine evolution timeline, Botschaft reference (legislative intent from the Federal Council's message), and scholarly commentary excerpt from OnlineKommentar.ch when available.

Verbatim text of ONE numbered Erwägung — the citable unit in Swiss practice (e.g. 'BGE 140 III 86 E. 2.3'). Use when the user already gave an e_number. If only a claim was given (no e_number): use find_relevant_erwaegung — never guess. Returns text + sibling Erwägung numbers. e_number: '1', '2.3', '5.2.1', …

AUTHORITATIVE LOOKUP for the current text of any Swiss law article — federal OR cantonal. Served from two local mirrors: • Federal (canton='CH', default): Fedlex mirror — core codes (OR, ZGB, StGB, StPO, ZPO, BV, SchKG, BGG/LTF, DBG, IPRG, AIG, BVG, KVG, AsylG, BGFA and dozens more), all three official languages (DE/FR/IT). • Cantonal: LexFind mirror — every cantonal statute and ordinance from all 26 cantons (ZH, BE, LU, UR, SZ, OW, NW, GL, ZG, FR, SO, BS, BL, SH, AR, AI, SG, GR, AG, TG, TI, VD, VS, NE, GE, JU), in each canton's publication language. Both jurisdictions return the same shape (title, articles with heading + text, article_count, canton, level). Use this BEFORE relying on training-data recall — Swiss statute text changes frequently and LLMs routinely hallucinate article content. Examples: get_law(abbreviation='BV', article='8'); get_law(sr_number='220', article='41'); get_law(canton='ZH', sr_number='554.5', article='1') for Art. 1 of the Zurich Hundegesetz.

Retrieve the FULL TEXT and article list of a specific Swiss law, federal or cantonal, by LexFind ID or SR/systematic number. For federal laws in the Fedlex mirror this is instant (local SQLite). For cantonal laws, the law is downloaded from LexFind as PDF, parsed with PyMuPDF, and segmented into articles (cached 30 days). Returns: title, entity, articles (article_num, heading, text), full_text, article_count. Use search_legislation first to find the right lexfind_id or systematic_number; then pass it here. For the core federal codes, get_law is still the fastest path.

Look up Materialien for a Swiss federal law article. Returns up to three things: `sources` = per-article digests of legislative intent (BV and BGFA only — 167 articles); `botschaft_documents` = the Federal Council messages that concern this article, with BBl citation, title and Fedlex link (620 SR numbers, 19,809 article links); `amendment_refs` = the AS/BBl publication locators from the statute's own footnotes. Empty `sources` means no digest exists for that law, NOT that the law has no legislative history — read `botschaft_documents` and cite the BBl reference. For full text of a message use search_botschaft.

Retrieve a single federal administrative-practice document by its doc_id (e.g. 'estv_ks_ks_nr_28', 'sem_weisungen_weisungen-aug-d'). Returns full body text, title, date, issuing authority, and PDF URL. Use search_practice first to discover the doc_id.

Get the official Regeste (head-note) of a Swiss court decision. The Regeste is the court's own formulation of the legal rule established — for BGEs especially, this is the canonical citation target. Often references specific Erwägungen via '(E. 5.2.1)' which can then be retrieved verbatim with get_erwaegung. USE THIS when the user asks 'what does this case stand for' or 'what is the rule from this decision'. Available for ~54% of federal decisions (100% of BGE).

Fetch a single OA legal publication (article, dissertation, commentary, etc.) by its pub_id. Returns full metadata + abstract + full text if available + cross-citations to statutes and decisions.

Fetch the full text of an OA legal publication by pub_id, on demand. Cached after first fetch so subsequent calls are instant. License-gated: only records under CC-BY-* (except CC-BY-ND), OA-Swiss-federal, or OA-author-permitted-reuse are extracted. ND/all-rights-reserved records return the upstream URL only. Use this when search_scholarship or get_scholarship returns only abstract/title and you need the article body to verify a claim or quote a passage.

Get aggregate statistics about the dataset. Optionally filter by court, canton, or year.

List all available courts with decision counts, date ranges, and language coverage. Use this to discover what data is available.

List the open-access legal scholarship sources currently indexed, with publication counts by source, type, and language. Use this to discover what corpora are available before searching.

ChatGPT Deep Research compatibility tool. Returns a ranked list of Swiss court decisions matching a query, each as {id, title, url, snippet}. Pair with `fetch` to retrieve a decision's full text by id. General (non-deep-research) clients should prefer `search_decisions`, which exposes filters (court, canton, date, language) and richer metadata.

Use this tool to retrieve and quote the VERBATIM text of Federal Council Botschaften (legislative messages). Where get_article_purpose answers 'why does Art. X exist?', this tool answers 'show me every Botschaft passage about TOPIC X'. Useful when the caller doesn't know which SR/article to ask for — e.g. starting from a concept like 'Vaterschaftsurlaub' or 'Klimaschutz'. Returns ranked passages (FTS5 BM25) with bbl_citation, page, section path, and an article anchor where the parser could identify one. Quote verbatim; every snippet has a stable Fedlex ELI URI.

Use this tool ONLY for article-anchored commentary from OnlineKommentar.ch — doctrinal discussion tied to a specific statute article. For the full OA scholarship corpus (which includes OnlineKommentar) use search_scholarship. Searches commentary text, titles, and article numbers. Returns ranked results with snippets, authors, and links. Useful for finding doctrinal discussion of a legal concept across multiple laws.

Use this tool to find COURT DECISIONS (Rechtsprechung): 1,050,000+ Swiss federal and cantonal decisions plus ~2,800 ECtHR decisions concerning Switzerland. Full-text search with keywords, phrases (in quotes), Boolean operators (AND, OR, NOT), prefix matching (word*), docket lookup (6B_1234/2025) and column-scoped search (regeste:keyword). Filter by court, canton, language, date range, chamber. Results are relevance-ranked and enriched with citation counts, statute references and is_leading_case. Use offset to page. Most recent decisions: empty query + sort='date_desc' + court filter. Not for statutes (search_laws), commentary (search_scholarship), or administrative guidance (search_practice).

Use this tool to find STATUTE ARTICLES by topic — full-text over every locally indexed article, federal (Fedlex mirror) AND cantonal (LexFind mirror, all 26 cantons), interleaved. Not for whole laws by name (search_legislation) or court decisions (search_decisions). BM25-ranked per corpus, merged by interleaving so each response surfaces both jurisdictions. Returns ranked snippets with article number, heading, law title, canton, and level ('federal' | 'cantonal'). Use this as the DEFAULT entry point when the user asks about any Swiss legal topic and you don't know which law or which jurisdiction applies. Filter with canton='ZH' (etc.) for cantonal-only, or jurisdiction='federal'/'cantonal' for explicit scoping. Examples: search_laws(query='Verjährung') — find statute-of-limitations provisions in federal + cantonal laws; search_laws(query='Hundehaltung', canton='ZH') — ZH dog-keeping rules; search_laws(query='Mietrecht', jurisdiction='federal') — federal-only tenancy law.

Use this tool to find WHOLE LAWS by name or subject — 33,000+ federal and cantonal enactments from LexFind.ch; the entry point for cantonal questions ('Hundegesetz Bern', 'loi sur l'énergie Vaud'). Not for article-level topic search (search_laws) or the core federal codes (get_law is instant there). All 26 cantons + federal, DE/FR/IT. Also the entry point for municipal regulations and federal ordinances outside the core Fedlex mirror. SINGLE-CALL MODE: set fetch_top_n_texts=1..3 and the top results are returned with the parsed full text + article list of the law itself — no follow-up get_legislation call needed. Ideal for 'what does cantonal law X say about Y' questions. For core federal codes (OR, ZGB, StGB, BV, StPO, ZPO, SchKG, BGG, DBG, IPRG, AIG, BVG, KVG etc.), prefer get_law / search_laws — they are instant and cover all three languages.

Use this tool for DIGESTED legislative history — per-article intent summaries and key arguments, not verbatim text. COVERAGE IS NARROW: BV and BGFA digests (167 articles) plus BV debate transcripts, and nothing else. For any other law this returns 0 hits, which means 'outside this index', not 'no materials exist'. Prefer search_botschaft, which covers all 6,154 Federal Council messages verbatim, or get_materialien(law_code) for the messages linked to one statute.

Use this tool when the question involves federal ADMINISTRATIVE PRACTICE (Verwaltungspraxis): Wegleitungen, Kreisschreiben, MWST-Infos, Weisungen, Rundschreiben, Vollzugshilfen — interpretive agency guidance, not court decisions. 1,892 documents: SECO commentary on the Arbeitsgesetz and ArGV 1-5, article by article (1,102, DE/FR/IT — the reference for employment-law questions); ESTV tax and VAT (438, DE/FR/IT); BAFU environment (297, DE); SEM migration/asylum/citizenship (55, DE). Returns ranked excerpts with authority, document number, date and a PDF link. NOT covered: BSV/AHV-IV, FINMA, BAG and all cantonal administrations — say so rather than implying a gap is an absence of guidance. For federal administrative decisions before 2017 use search_decisions(court='ch_vb') (VPB/JAAC).

Use this tool for open-access SCHOLARSHIP (Lehre): OA journal articles (sui generis et al.), OA legal commentaries (OnlineKommentar, OpenLegalCommentary — this tool SUBSUMES search_commentaries), dissertations and theses from Swiss university repositories, and federal legal-policy reports. Returns ranked results with snippets, authors, DOI, and direct links. Filters by source, publication type, language, and year range. Sort by relevance or year; an author filter may be used on its own (no query) for a bibliographic browse, e.g. all works by a given author, newest first.