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Edge Case Museum

von pipeworx-ioVersion 0.2.1i★ –iComputer oder Cloud
Name in der Registryio.github.pipeworx-io/edge-case-museum

Installieren

Überblick

Beschreibung vom Entwickler (englisches Original)

Edge Case Museum MCP — 'Your code works. Except for these wonderfully terrible inputs.'

Die drei Säulen von PopNx MCP

Diese drei werden nie zu einer Punktzahl zusammengefasst: Meinungen, Messungen und Beliebtheit sind verschiedene Dinge.

Was du damit machen kannst

Für diesen Server haben wir noch keine Zusammenfassung in einfacher Sprache geschrieben. Unten stehen die Fakten, die wir aus der Registry gelesen haben.

  • Verbindung: Computer oder Cloud
  • Transport: stdio, Streamable HTTP
  • Kategorie: Entwicklertools
  • Das musst du eintragen: PIPEWORX_API_KEY

Installation

Wähle die KI-App, die du nutzt, und kopiere die Einstellungen.

Bevor du installierst

Als geheim markierte Werte sind Schlüssel zu deinem Konto. Gib sie nie weiter und füge sie nie in einen Chat ein.

Du brauchst

  • Läuft in der CloudNichts zu installieren; die Verbindung läuft übers Internet
  • npmNode.js installiert (für den Befehl npx)

Welche App nutzt du?

Wähle oben deine App. Wir merken sie uns, damit der Button beim nächsten Mal „In … installieren“ anzeigt.

Funktioniert in Claude im Web, auf dem Desktop und auf dem Handy:

  1. Öffne Settings → Connectors
  2. Tippe auf Add custom connector
  3. Füge die Adresse unten ein und tippe auf Add
  4. Wenn eine Anmeldung verlangt wird, melde dich beim Dienst des Entwicklers an
SettingsConnectors1+ Add2https://…3
https://gateway.pipeworx.io/edge-case-museum/mcp

Oder führ ihn auf deinem Computer aus

Öffne Claude Desktop → Settings → Developer → Edit Config und füge dies in claude_desktop_config.json ein

{
  "mcpServers": {
    "edge-case-museum": {
      "command": "npx",
      "args": [
        "-y",
        "@pipeworx/mcp-edge-case-museum"
      ],
      "env": {
        "PIPEWORX_API_KEY": "your-value"
      }
    }
  }
}

Führe das in deinem Terminal aus

claude mcp add --transport http edge-case-museum https://gateway.pipeworx.io/edge-case-museum/mcp

Oder führ ihn auf deinem Computer aus

claude mcp add edge-case-museum --env PIPEWORX_API_KEY=your-value -- npx -y @pipeworx/mcp-edge-case-museum

Trag die leeren Werte ein, bevor du ihn startest.

In Cursor öffnen

Oder kopier die Einstellungen selbst

In .cursor/mcp.json in deinem Projekt oder in ~/.cursor/mcp.json einfügen

{
  "mcpServers": {
    "edge-case-museum": {
      "url": "https://gateway.pipeworx.io/edge-case-museum/mcp"
    }
  }
}

Oder führ ihn auf deinem Computer aus

In Cursor öffnen

Oder kopier die Einstellungen selbst

In .cursor/mcp.json in deinem Projekt oder in ~/.cursor/mcp.json einfügen

{
  "mcpServers": {
    "edge-case-museum": {
      "command": "npx",
      "args": [
        "-y",
        "@pipeworx/mcp-edge-case-museum"
      ],
      "env": {
        "PIPEWORX_API_KEY": "your-value"
      }
    }
  }
}

Dein Browser fragt, ob er die App öffnen darf, dann zeigt die App die Einstellungen und bittet dich um Bestätigung. Schlüsselwerte bleiben leer, damit du sie selbst einträgst.

In VS Code öffnen

Oder kopier die Einstellungen selbst

In .vscode/mcp.json in deinem Projekt einfügen

{
  "servers": {
    "edge-case-museum": {
      "type": "http",
      "url": "https://gateway.pipeworx.io/edge-case-museum/mcp"
    }
  }
}

Oder führ ihn auf deinem Computer aus

In VS Code öffnen

Oder kopier die Einstellungen selbst

In .vscode/mcp.json in deinem Projekt einfügen

{
  "servers": {
    "edge-case-museum": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@pipeworx/mcp-edge-case-museum"
      ],
      "env": {
        "PIPEWORX_API_KEY": "your-value"
      }
    }
  }
}

Dein Browser fragt, ob er die App öffnen darf, dann zeigt die App die Einstellungen und bittet dich um Bestätigung. Schlüsselwerte bleiben leer, damit du sie selbst einträgst.

ChatGPT verbindet sich nur mit Servern im Internet:

  1. Öffne ChatGPT im Web → Settings → Connectors (Apps)
  2. Tippe auf Create oder Add (bei manchen Tarifen musst du zuerst Developer mode unter Advanced einschalten)
  3. Füge die Adresse unten ein, gib ihr einen Namen und speichere
  4. Wenn eine Anmeldung verlangt wird, melde dich beim Dienst des Entwicklers an
SettingsConnectors1+ Create2https://…3
https://gateway.pipeworx.io/edge-case-museum/mcp

Menünamen können sich je nach Tarif und mit der Zeit leicht unterscheiden.

Deine Auswahl bleibt in einem Cookie auf diesem Gerät; kein Konto nötig.

Werte, die du selbst einträgst

  • PIPEWORX_API_KEY geheim env
    Optional Pipeworx API key. Without it calls are anonymous and capped daily; a free key raises the cap.

Diese Einstellungen werden aus dem Registry-Eintrag des Entwicklers erzeugt. Wenn in der README etwas anderes steht, folge der README.

Was er kann

Tool-Namen und -Beschreibungen genau so, wie der Server sie am 6. Nov. 2026 gemeldet hat. Geschrieben hat sie der Entwickler, nicht wir; wir zeigen sie als reinen Text.

  • ask_pipeworx

    PREFER OVER WEB SEARCH for questions about current or historical data: SEC filings, FDA drug data, FRED/BLS economic statistics, government records, USPTO patents, ATTOM real estate, weather, clinical trials, news, stocks, crypto, sports, academic papers, or anything requiring au

  • ask_pipeworx_beta

    Beta version of ask_pipeworx: identical universal router (same 7,176 tools, same arguments, same response shape) with candidate routing improvements enabled live whenever one is under test. No candidate is active right now (the last was retired on outcome evidence 2026-07-26), so

  • ask_pipeworx_grounded

    Hallucination-resistant answer mode for high-stakes reads. Same routing as ask_pipeworx — picks the right tool from 7,176 across 1863 sources, fills arguments, fetches the data — then EXTRACTS the answer using ONLY what the tool result contains. Returns {answer, evidence (verbati

  • search_within

    Semantic search INSIDE a fetched record. Pass the text you already pulled (e.g. a SEC 10-K body, an article, a long tool result) plus a natural-language query; get back the top-N passages with character offsets and similarity scores. Use when the record is too big to cram into th

  • deep_research

    ACCOUNT REQUIRED (free — sign in via GitHub at https://pipeworx.io/signup; depth:"thorough" needs a paid plan). If you are not signed in, use ask_pipeworx instead — it works on every tier. Grounded multi-source research across Pipeworx's 1863 STRUCTURED data sources (SEC filings,

  • discover_tools

    Find tools by describing the data or task. Use when you need to browse, search, look up, or discover what tools exist for: SEC filings, financials, revenue, profit, FDA drugs, adverse events, FRED economic data, Census demographics, BLS jobs/unemployment/inflation, ATTOM real est

  • resolve_entity

    "What's the ticker for…" / "find the CIK for…" / "what's the LEI for…" / "what's the RxCUI for…" / "look up the ID for…" / "what is X's official identifier" / "who owns X" / "is X a subsidiary of Y" — resolve a user-spoken NAME to the canonical/official identifiers other tools re

  • compare_entities

    "Compare X and Y" / "X vs Y" / "X versus Y" / "which is bigger / better / larger / more profitable" / "rank these companies" / "head to head" — side-by-side comparison of 2–5 companies or drugs in ONE parallel call. ALWAYS PREFER over sequential single-pack lookups when comparing

  • subscribe

    Create a proactive monitoring subscription to a live-data event stream. Returns the new subscription id. Requires a Pipeworx OAuth account (anonymous + BYO cannot persist subscriptions). Supported types: "sec_8k" (8-K filings matching ticker + item codes — e.g. items:["5.02"] = o

  • unsubscribe

    Cancel a subscription by id. Ownership is enforced — you can only cancel your own subscriptions. The row is deactivated (not deleted) so its historical events stay available via recent_alerts.

  • list_subscriptions

    List the caller's active subscriptions. Returns id, type, params, created_at, last_fired_at, fire_count for each. Use this to review what you're monitoring before adding more or to find an id to cancel.

  • recent_alerts

    Pull fired events from your subscription feed. Returns the most recent alerts the evaluator has written to your persisted feed — each carries source, citation_uri (pipeworx:// when available), and the raw event payload. Filter by type (e.g. "sec_8k") and/or since (ISO timestamp).

  • entity_profile

    "Tell me about X" / "research Acme" / "brief me on Tesla" / "what does Apple do" / "company profile for Microsoft" / "give me the rundown on NVDA" / "everything you know about $TICKER" — full cross-source profile of a US public company in ONE parallel call. ALWAYS PREFER over cha

  • recent_changes

    "What's new with X" / "latest on Y" / "what happened to Z this week / month / quarter" / "updates on Acme" / "news on Tesla recently" / "what's happening with Apple" — change feed for a company in the last N days/weeks/months in ONE parallel call. Fans out to SEC EDGAR (filings s

  • validate_claim

    "Is it true that…" / "fact check" / "verify the claim that…" / "did X really…" / "was Y actually…" / "confirm or refute" / "true or false" — natural-language claim verification against authoritative sources. Use whenever the agent needs to check whether something a user said is f

  • company_facts

    TYPED, DETERMINISTIC financial facts for a US public company for an EXPLICITLY NAMED reporting period — "Apple revenue for fiscal 2023", "Walmart net income FY2026 Q3", "Microsoft cash at the end of fiscal 2024". PREFER OVER entity_profile / get_company_financials whenever the pe

  • company_register_search

    Search the NATIONAL BUSINESS REGISTERS by company name and get the register's own id back — a Companies House number, a Norwegian organisasjonsnummer, a Finnish business id, a SIREN, a Japanese corporate number, an Estonian registry code, a CNPJ, or an LEI. Use this when you want

  • scan_dependency

    Composite "should I add this npm package to my project" check in ONE call — fans out across deps.dev (license + advisories + version history) and bundlephobia (gzipped/minified bundle size, dependency count, ESM/tree-shake support). Use whenever an agent asks "is X safe / popular

  • bet_research

    Research a Polymarket bet by pulling the relevant Pipeworx data for it in one call. Pass a market slug ("will-kristi-noem-win-the-2028-republican-presidential-nomination"), a polymarket.com URL, or a question text. A dated slug ("...-by-june-30-2026") still resolves after it sett

  • polymarket_arbitrage

    Find arbitrage opportunities on Polymarket via monotonicity violations + partition-sum checks. Call with NO args for a `trending_scan` of the top ~200 markets by weekly volume; pass `event` for the strongest per-event partition_check, or `topic` for a themed cross-event scan. `ev

  • polymarket_edges

    Scan top Polymarket markets and return opportunities where Pipeworx data disagrees with market price. Built for "what should I bet on today" — agents discover opportunities without paging hundreds of markets. FIVE MODEL FAMILIES grouped into three response segments under by_segme

  • polymarket_kalshi_spread

    Cross-venue spread between Kalshi and Polymarket for the same resolving question. The two venues sometimes price the same outcome 2-25pp apart because their participant pools differ — when the bet shapes are equivalent that delta is a real signal, when they aren't the tool says s

  • polymarket_fill_risk

    Realizable-vs-theoretical edge check against live CLOB order-book depth — AND Polymarket's own taker fee, which is never zero and is folded in rather than left for you to add (fleet #3446: r/PredictionsMarkets flagged a "clean" fill that quietly omitted it as optimistic in the di

  • polymarket_edge_tracker

    Edge persistence and decay telemetry built from daily polymarket_edges snapshots. Answers "how long has this edge existed and is it shrinking?" — a fresh wide edge and a 3-week-old wide edge are different trades (the latter is wide for a reason nobody is willing to take). Args: d

  • kalshi_weather_edge

    Prices Kalshi daily high-temperature markets against the NWS forecast for the market's OWN settlement station, and measures whether that forecast actually beats the market. Two modes. LIVE (default): returns the full strike ladder for one city and settlement date with market_prob

  • resolution_audit

    Extract the settlement clause of a single Polymarket (.com or .us) or Kalshi market: who publishes the settling number (source), the clock time + timezone it is taken at (falling back to the market TITLE when the clause itself says "the time range specified in the title" — e.g. P

  • resolution_diff

    Field-by-field diff of TWO markets' settlement clauses (one from each of `a` and `b`; either can be Polymarket .com, Polymarket US, or Kalshi) — runs resolution_audit on both sides and compares source, settle time, precision, comparison_basis, and evidence standard. Returns `equi

  • release_calendar_markets

    JOIN of the official release calendar (econ data, the FOMC, FDA decisions, SEC rules) against LIVE Polymarket/Kalshi markets — which scheduled releases land in the next N hours, and which live markets resolve on them. This is a POSITIONING tool, not a speed product: results are c

  • prediction_calibration

    REALIZED win rate by shown price and minutes elapsed for short-horizon crypto up/down markets, net of taker fee — read from our own settled-outcomes archive, not from live prices. Answers the one question no venue will: "a side shown at 82 with five minutes left, how often did it

  • updown_venue_compare

    The same 15-minute crypto "up or down" window priced on polymarket.com, Polymarket US and Kalshi, side by side, with whether each pair is actually the same contract. Pass asset (btc | eth | sol | xrp | bnb) and window ("current" default, "next", "previous", or the window START as

  • updown_divergence_rate

    How often two venues settled the SAME 15-minute crypto window differently, over every settled window on record. Compares polymarket.com (Chainlink TWAP) with Kalshi and with Polymarket US (both CF Benchmarks BRTI), and Kalshi with Polymarket US as the same-feed control. Per pair:

  • archive_evidence

    What did a web page say on a given date? Finds the archived capture of a URL nearest that date across the Internet Archive Wayback Machine, Common Crawl and Arquivo.pt, reads it, and returns the readable text (HTML stripped) with the capture timestamp, a link to the archived copy

  • archive_compare

    What changed on a web page between two dates? Resolves the archived capture nearest each date (Internet Archive Wayback Machine, Common Crawl, Arquivo.pt), extracts the readable text of both, and returns a text-level diff: the segments removed and added, a similarity score, and b

  • research_row

    Claygent-style per-row research: answer ONE question about ONE company and return a JSON object matching your output_schema, with every field wrapped in its own evidence — {value, evidence_url, quote, status}. status is NEVER self-reported by the model: "found" means this code in

  • classify_row

    Cheap categorization: given a company and a list of candidate labels, decide which labels apply — the most common GTM/AI usage shape (tagging a list by industry, ICP fit, etc.), one small model call. Same evidence contract as research_row: each label comes back {label, applies, e

  • pipeworx_trending

    What other AI agents are calling on Pipeworx right now. Returns the top tools, top packs, and total call volume over a recent window (24h, 7d, or 30d). Useful for: (1) discovering what data sources are hot for current events, (2) confirming a popular tool is the canonical choice

  • suggest_questions

    What can I ask Pipeworx? / what is Pipeworx good for? / what can you do? / give me ideas / show me examples / getting started / what data do you have? — the onboarding entry point for an agent that just connected and wants to know what is worth asking. Returns category-bucketed e

  • generate_llms_txt

    Generate a production-ready llms.txt file for any URL so AI crawlers (ChatGPT, Claude, Perplexity) can index the site cleanly. Fetches the page, extracts title/description/key links, and emits the standard llms.txt markdown format. Output is a single text blob ready to drop at si

  • ai_visibility_check

    Probe one or more LLMs for what they know about a business / brand / product / topic and score visibility (0-100) per model. Default model is Workers AI Llama-3.3-70b (free); pass `_apiKey` to also probe Anthropic (BYO key — you pay Anthropic directly for those calls). Returns pe

  • scan_competitor_ai_presence

    Compare AI visibility across multiple entities side-by-side. Probes each entity (your brand + N competitors) with ai_visibility_check, ranks by score, surfaces which is most/least recognized. Useful for competitive AI-marketing audits: "does Claude know about us as well as our co

  • pipeworx_feedback

    Tell the Pipeworx team something is broken, missing, or needs to exist. Use when a tool returns wrong/stale data (bug), when a tool you wish existed isn't in the catalog (feature/data_gap), or when something worked surprisingly well (praise). ONLY for tools served by this Pipewor

  • remember

    Save data the agent will need to reuse later — across this conversation or across sessions. Use when you discover something worth carrying forward (a resolved ticker, a target address, a user preference, a research subject) so you don't have to look it up again. Stored as a key-v

  • recall

    Retrieve a value previously saved via remember, or list all saved keys (omit the key argument). Use to look up context the agent stored earlier — the user's target ticker, an address, prior research notes — without re-deriving it from scratch. Scoped to your identifier (anonymous

  • forget

    Delete a previously stored memory by key. Use when context is stale, the task is done, or you want to clear sensitive data the agent saved earlier. Pair with remember and recall.

  • edge_cases_find

    Edge Case Museum: describe what you are implementing in plain words ("username uniqueness", "parse a CSV upload", "store and add up money amounts", "schedule a reminder in the user's timezone", "sort customer names") and get the surprising inputs that break that kind of code. Eac

  • edge_case_get

    Edge Case Museum: one exhibit in full by id (from edge_cases_find or edge_cases_browse): the assumption it breaks, the exact input, what goes wrong and why, every repro (executed Python/Node.js repros with their captured output and runtime version; other stacks labelled documente

  • edge_cases_browse

    Edge Case Museum: browse the collection. With no arguments, lists the categories (unicode, datetime, float-money, sorting, filenames, parsing, integers, names-addresses) with counts and their most common tags. With category or tag, lists the exhibits in it: id, title, the assumpt

  • edge_cases_test_file

    Edge Case Museum: one runnable test file (pytest for python, node:test for javascript) bundling the inputs from the exhibits relevant to what you are implementing, as parametrized cases you point at your own function. The file runs as generated against a stub, with TODO marks whe

Basischecksi

Wir prüfen Informationen, die jeder sehen kann; den Code haben wir nicht gelesen. Checks, die nicht zutreffen, werden nicht mitgezählt. · Geprüft am 8. Nov. 2026

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    Der Registry-Name wurde mit dem GitHub-Konto pipeworx-io bestätigt, dem das Repo gehört

  • … Noch nicht geprüft

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    Dieses Repo haben wir noch nicht von GitHub gelesen

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    Antwort in 748 ms (HTTP 200)

  • – Nicht zutreffend

    Anmeldung mit OAuth

    Keine Anmeldung nötig

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    Wir haben 48 Tool-Beschreibungen gelesen und keine versteckten Anweisungen an die KI gefunden

Im Vergleich mit anderen in Entwicklertoolsi

  • Mehr Sterne als 0 % der anderen 4924 Server in dieser Kategorie
  • Neuer in der Registry veröffentlicht als 83 % der anderen 4924 Server in dieser Kategorie
  • Basischecks gleich gut wie oder besser als bei 100 % der anderen 4924 Server in dieser Kategorie

Verglichen mit allen aktiven Servern dieser Kategorie in der Registry. Sterne zählen nur, wenn dem Herausgeber das Repo gehört.

Häufige Fragen

Ist Edge Case Museum sicher?

Er hat 3 von 3 zutreffenden Basischecks bestanden. Den Code haben wir nicht gelesen. Bevor du einen Schlüssel oder Token hinzufügst, sieh nach, welche Zugriffe der Server verlangt, und nutze einen Schlüssel, der nur die Berechtigungen hat, die du brauchst.

Welche Schlüssel oder Codes braucht er?

Das musst du eintragen: PIPEWORX_API_KEY

Läuft er auf meinem Computer oder in der Cloud?

Beides geht: Installiere ihn auf deinem Computer oder verbinde dich mit der Cloud-Version.

Wird er noch gepflegt?

Das GitHub-Repo wurde zuletzt – geändert, und die neueste Version (0.2.1) kam vor 7 Tagen in die Registry.

Welche Apps können ihn nutzen?

Apps, die MCP unterstützen, etwa Claude Desktop, Claude Code, Cursor und VS Code. Er verbindet sich per URL, also funktionieren auch Apps, die Remote-MCP-Server akzeptieren, zum Beispiel ChatGPT im Entwicklermodus.

Was kann ich stattdessen nutzen?

In derselben Kategorie: GitHub, Desktop Commander, Cloudflare MCP

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README vom Entwickler

README öffnen

Unverändert aus dem Repo des Entwicklers übernommen. PopNx MCP hat den Inhalt weder geprüft noch empfiehlt es ihn. HTML, Bilder und Skripte wurden entfernt. Links führen von dieser Website weg.

edge-case-museum

Your code works. Except for these wonderfully terrible inputs.

Part of Pipeworx — an MCP gateway connecting AI agents to 1863+ live data sources. This is an independent, unofficial integration — not affiliated with, endorsed by, or published by the upstream provider.

By Mojibake, creators of Pipeworx.

Tell it what you are building ("username uniqueness", "parse a CSV upload", "store and add up money amounts", "schedule a reminder in the user's timezone") and it hands back the inputs that quietly break that kind of code: the assumption each one breaks, the exact bytes, what goes wrong, why, the safer pattern, and a repro in Python and JavaScript whose output came from actually running it. Then it writes you a test file of those inputs, pointed at your own function.

Three exhibits

Every output below was printed by running the code, by the same harness that checks the whole collection (Python 3.14.2, Node.js v22.22.2).

1. One NaN can leave the rest of your list unsorted

edge_case_get({ id: "nan-in-sort" })

nan = float("nan")

print(sorted([3, nan, 1]))

[3, nan, 1]

console.log([3, NaN, 1].sort((a, b) => a - b));
[ 3, NaN, 1 ]

Not "NaN ends up somewhere odd". The 3 and the 1 are left out of order. Every comparison with NaN is false, so the sort sees NaN as equal to everything. That breaks transitivity (3 "equals" NaN, NaN "equals" 1, so 3 "equals" 1), and the algorithm concludes the list is already sorted. Python promises nothing for inconsistent comparisons. ECMAScript makes the order implementation-defined.

2. "01/01/68" is 2068 in Python and 1968 in Node.js

edge_case_get({ id: "two-digit-year-century-pivot-mismatch" })

for s in ("01/01/49", "01/01/50", "01/01/68", "01/01/69"):

print(s, "->", datetime.strptime(s, "%m/%d/%y").year)

01/01/49 -> 2049 01/01/50 -> 2050 01/01/68 -> 2068 01/01/69 -> 1969

for (const s of ['01/01/49', '01/01/50', '01/01/68', '01/01/69'])

console.log(s, '->', new Date(s).getFullYear());

01/01/49 -> 2049 01/01/50 -> 1950 01/01/68 -> 1968 01/01/69 -> 1969

Python follows the POSIX pivot at 69. V8 pivots at 50. The two agree on every two-digit year except 50 through 68, where they are a century apart. Test a handful of dates and you will probably never hit one.

3. Intl says the Iraqi dinar has no decimals. ISO 4217 says it has three.

edge_cases_find({ context: "store and add up money amounts", language: "javascript" })

for (const c of ["USD", "JPY", "BHD", "KWD", "CLF", "IQD", "HUF"]) {

const digits = new Intl.NumberFormat("en-US", { style: "currency", currency: c }) .resolvedOptions().maximumFractionDigits; console.log(c, digits); }

USD 2 JPY 0 BHD 3 KWD 3 CLF 4 IQD 0 HUF 0

The first lesson is that amount * 100 is wrong for JPY (a 100x overcharge) and for BHD (a 10x undercharge). The second is quieter: the obvious fix, asking Intl how many decimals a currency has, returns CLDR display data, not ISO 4217. IQD is 3 in ISO 4217 and HUF is 2, and Intl reports 0 for both. Store the exponent your payment processor uses. Don't derive it from a formatter.

And then it writes the test

edge_cases_test_file({ context: "parse a CSV upload", language: "python" }) returns a pytest file of eight cases from seven CSV exhibits. Pointed at the parser most of us write first, list(csv.reader(io.StringIO(text))):

PASSED test_edge_case[csv-formula-injection-excel]

PASSED test_edge_case[csv-crlf-trailing-blank-line0] PASSED test_edge_case[csv-crlf-trailing-blank-line1] PASSED test_edge_case[csv-quoted-field-with-newline] PASSED test_edge_case[csv-doubled-quote-escaping] PASSED test_edge_case[csv-quoted-field-with-comma] FAILED test_edge_case[csv-utf8-bom-first-header] FAILED test_edge_case[csv-semicolon-delimited-european-excel] 2 failed, 6 passed

Two real bugs: the first header comes back as "name" from a file saved as Excel's "CSV UTF-8", and a semicolon-delimited export from a decimal-comma locale parses as one column. Each failure names the exhibit that explains it.

What is in it

122 exhibits, every one with at least one repro that was executed:

CategoryExhibitsFor example
Unicode15NFC vs NFD usernames, Turkish dotted I, ß case folding, Cyrillic homoglyphs, zero-width characters, Zalgo text
Dates and time18DST gaps and overlaps, Nepal's +05:45, Samoa's missing day, leap seconds, 2038, ISO week years
Floating point and money17round(2.675, 2), (1.005).toFixed(2), banker's rounding, currency minor units, -0 balances
Sorting and comparison14collation vs code points, Swedish å after z, [10, 9, 1].sort(), boolean comparators
Filenames and paths15CON.txt, trailing dots, os.path.join with an absolute part, NTFS streams, 255-byte names
Parsing15CSV quoting and BOMs, JSON duplicate keys and 64-bit ids, WHATWG backslashes, valid emails rejected
Integers14MAX_SAFE_INTEGER + 1 === MAX_SAFE_INTEGER + 2, parseInt(null, 36), -7 % 2
Names and addresses14particles in surnames, mononyms, "Null" as a surname, ZIP codes with leading zeros

Tools

  • edge_cases_find({ context, language?, limit? }) — what you are implementing, in plain words, to the exhibits that matter for it. Each comes with the repro for your language and a refine_tags list to narrow down.
  • edge_case_get({ id }) — one exhibit in full: every repro with its captured output and runtime version, the why, the fix, related exhibits, sources.
  • edge_cases_browse({ category?, tag? }) — the collection by category (unicode, datetime, float-money, sorting, filenames, parsing, integers, names-addresses) or by tag (username, csv, money, timezone, ...).
  • edge_cases_test_file({ context, language }) — one runnable pytest or node:test file bundling the relevant inputs as cases. It runs as generated against a stub; replace the stub (marked TODO) with your function and the failures tell you which exhibit to read.

Install

Remote (no setup)
{

"mcpServers": { "edge-case-museum": { "url": "https://gateway.pipeworx.io/edge-case-museum/mcp" } } }

This endpoint also carries the shared Pipeworx tools (ask_pipeworx, discover_tools, and friends).

Local
{

"mcpServers": { "edge-case-museum": { "command": "npx", "args": ["-y", "@pipeworx/mcp-edge-case-museum"] } } }

The whole collection ships inside the package. No network calls, no account.

Auth

Keyless.

Why trust it

  • No output is typed from memory. Every Python and JavaScript repro is executed by a committed harness, and its expected_output is what the run printed. verified_with names the runtime (for example Python 3.14.2, Node.js v22.22.2), because some of these behaviours change between versions and you should know which one we saw.
  • The harness can fail, and has. Change one character of an expected output and the run goes red with the diff. A repro whose code or output was edited without re-running it cannot be baked into the pack at all: the bake checks a hash the harness recorded.
  • Stacks we did not run are labelled. Postgres, Windows and macOS filesystem behaviour appear as documented, with the source that says so, never as verified.
  • Every exhibit cites its spec or docs. Unicode annexes, RFC sections, the ECMAScript spec, IEEE 754 references, ISO 4217, IANA tz, the language docs. Written in our own words.

Data sources

  • Exhibits written for this collection by Mojibake, each citing the standard or documentation it rests on.
  • Some inputs come from the Big List of Naughty Strings by Max Woolf (MIT licence); exhibits that use one say so in their sources.
  • No real person's name, address or contact detail appears anywhere. The names-and-addresses exhibits use invented examples and state facts about naming and addressing systems.

Contribute an exhibit

Add one file, src/exhibits/CATEGORY/ID.json (copy any existing exhibit for the shape), with your repros' code but no expected_output. Run node src/harness.mjs --only ID --capture: it executes each repro, writes the real output into your file, and records it. Read what it captured; if the output does not say what your explanation says, the explanation is wrong. Then node src/bake.mjs and open a pull request. An exhibit whose repro has not been run by the harness will not bake.

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

{

"mcpServers": { "edge-case-museum": { "url": "https://gateway.pipeworx.io/edge-case-museum/mcp" } } }

What this endpoint actually serves

tools/list at https://gateway.pipeworx.io/edge-case-museum/mcp returns the tools in the table above plus the shared Pipeworx meta-tools — ask_pipeworx, discover_tools, search_within, remember/recall and the rest of the gateway-wide set. So the tool count you see is larger than this table: a single-pack endpoint currently lists roughly 30 shared tools alongside the pack's own. The connection's initialize response states its exact scope, and is the authoritative answer for a given day.

This is deliberate, not multiplexing by accident. The meta-tools are what let a scoped connection answer a question this pack does not cover — via ask_pipeworx, which routes across the whole catalog — without you adding a second MCP server. There is currently no way to mount a pack endpoint without them; if the extra schemas cost you more context than the routing is worth, connect to the full gateway once rather than to several pack endpoints.

Or connect to the full Pipeworx gateway to get every pack's tools listed directly, instead of just this one's:

{

"mcpServers": { "pipeworx": { "url": "https://gateway.pipeworx.io/mcp" } } }

Both URLs reach the same gateway and the same 1863+ data sources. The only difference is which pack's tools are listed directly; ask_pipeworx reaches all of them from either one.

No MCP client? Call it over HTTP

curl -X POST https://gateway.pipeworx.io/v1/tools/edge_cases_find \

-H 'Content-Type: application/json' \ -d '{"context":"username uniqueness","language":"python"}'

No account needed for the first calls. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/edge_cases_find. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.

Run it from npm

@pipeworx/mcp-edge-case-museum is a local stdio bridge to the Pipeworx gateway: your MCP client starts it with npx, and it forwards every call to the same https://gateway.pipeworx.io/edge-case-museum/mcp endpoint shown above. It needs network access; there is no offline mode.

{

"mcpServers": { "edge-case-museum": { "command": "npx", "args": ["-y", "@pipeworx/mcp-edge-case-museum"] } } }

Without a key it calls anonymously, capped at 50 calls a day. A free account raises that to 200 a day: get a key at https://pipeworx.io/signup and add "env": { "PIPEWORX_API_KEY": " " } to the server entry. The key is sent as a Bearer token, the same way a hosted connection sends it, so calls are metered and billed exactly as they are there.

It lists only this pack's tools by default. Set PIPEWORX_META_TOOLS=1 to also list ask_pipeworx and the other gateway-wide tools.

Behind an HTTPS proxy: Node's built-in fetch does not read HTTPS_PROXY by default. Newer Node releases honour it when NODE_USE_ENV_PROXY=1 is set; check your Node version's documentation.

Using with ask_pipeworx

Instead of calling tools directly, you can ask qu

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