reference-data-mcp-server MCP Server
Countries, timezones, elements, constants, HTTP status codes, unit conversion, and MIME type lookup.
Publisher claimed. No tool list reported, and Pod has not connected to this server.
Status
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Connect
Published as @cyanheads/reference-data-mcp-server on npm. Runs locally.
Known issues
39 problems reported by people outside the maintainer team. Issues filed by the project's own owners, members and collaborators are excluded — those are release checklists and internal refactors, not things that will go wrong for you. Showing 12.
Most discussed
feat(responses): surface match_strategy in ref_constant_lookup and fuzzy-match notice in ref_geo_lookup
Two lookup tools perform fuzzy matching but return results with no indication of how the match was made. An agent that queried "Planck" and received the Planck constant (h) can't tell whether the service matched exactly on the symbol or picked h from among multiple fuzzy candidates that also matched. Similarly, an agent querying "brasil" (misspelled) and receiving Brazil's full record has no signal that the match was fuzzy — it cannot tell whether to normalize the canonical name in follow-up cal
Read the thread · 2026-05-29 · closed · 2 comments
bug(ref_unit_convert): "mph" and "BTU" in parameter describe and error recovery are unrecognized units
Server version
0.1.6
mcp-ts-core version
0.9.13
Runtime
Bun
Runtime version
Bun 1.3.x
Transport
stdio
Description
The `ref_unit_convert` tool contains three locations where `mph` and/or `BTU` are given as example unit abbreviations, but neither is recognized by the underlying `convert-units@2.3.4` library. Calling the tool with these inputs returns `unknown_unit` errors, directly contradicting the documentation that offers them as examples.
Issue #12
Read the thread · 2026-05-29 · closed · 2 comments
bug(ref_http_status): float query (e.g., "404.5") silently truncates to integer via parseInt
Server version
0.1.2
mcp-ts-core version
0.9.9
Runtime
Bun
Runtime version
Bun 1.3.11
Transport
HTTP (Streamable HTTP)
OS
macOS 25.1.0
Description
ref_http_status silently returns a valid result when given a float query like "404.5" or "503.5". parseInt("404.5", 10) returns 404, so the service finds and returns the 404 record — as if the input was the valid code 404. A float is not a valid HTTP status code; the tool should return not-found r
Read the thread · 2026-05-25 · closed · 2 comments
bug(ref_mime_type): MIME type query with parameters (e.g., text/plain; charset=utf-8) returns not-found instead of stripping parameters
Server version
0.1.2
mcp-ts-core version
0.9.9
Runtime
Bun
Runtime version
Bun 1.3.11
Transport
HTTP (Streamable HTTP)
OS
macOS 25.1.0
Description
ref_mime_type fails with a not-found error when the query includes MIME type parameters (the ; suffix common in HTTP Content-Type headers). Agents frequently encounter full content-type strings like text/plain; charset=utf-8 or application/json; charset=utf-8 and pass them directly as the query — the
Read the thread · 2026-05-25 · closed · 2 comments
bug(ref_unit_convert): below_absolute_zero error misrepresents the Kelvin equivalent as absolute zero
Server version
0.1.2
mcp-ts-core version
0.9.9
Runtime
Bun
Runtime version
Bun 1.3.11
Transport
HTTP (Streamable HTTP)
Description
The below_absolute_zero error message is misleading. The parenthetical (≈ -26.85 K) reads as "absolute zero is approximately -26.85 K", when it is actually meant to convey "your input temperature in Kelvin is -26.85 K". This is factually wrong to a reader parsing the message quickly.
A secondary issue: -459.67 F (which equals
Read the thread · 2026-05-25 · closed · 2 comments
Most recent
feat(ref_unit_convert): accept "mph"/"kph" aliases and document the mile-per-hour unit
ref_unit_convert cannot convert miles per hour as documented. The description's speed set is "m/s, km/h, knot, ft/s" — omitting mile-per-hour entirely — while the underlying convert-units library does support it under the abbreviation m/h. So "mph" is rejected (Unrecognized unit "mph". Use plain abbreviations: "C" … "km", "kg", "kWh", "Pa" — no speed unit among the examples), and the working spelling m/h appears only as an incidental ex
Read the thread · 2026-08-21 · open · 0 comments
docs(README): ref_constant_lookup entry count overstated as "~360"
Two README lines describe the CODATA 2022 physical constants dataset as "~360 entries" — `src/data/physical-constants.ts` currently defines 32 (`constants.length === 32`), roughly a 10x overstatement.
Location
- Line 110: "Look up CODATA 2022 physical constants (~360 entries)."
- Line 175: "constants (CODATA 2022, ~360 entries)"
Expected
Correct the count to the actual dataset size, or if ~360 is meant to describe the full CODATA 2022 standard (this dataset's header comment says
Read the thread · 2026-07-17 · closed · 1 comment
bug(ref_constant_lookup): name queries report match_strategy "exact_symbol" instead of "exact_name"
ref_constant_lookup returns match_strategy: "exact_symbol" for queries that are full constant names, when it should return "exact_name". The looked-up constant is correct — only the reported match provenance is wrong.
Reproduction
{ query: "Rydberg constant" } →
{ "name": "Rydberg constant", "symbol": "R∞", "value": 10973731.568157, "match_strategy": "exact_symbol", ... }
Expected match_strategy: "exact_name" — the query is the exact name, not the symbol R∞.
T
Read the thread · 2026-07-17 · closed · 1 comment
bug(ref_timezone_convert): DST spring-forward gap datetimes convert to a non-invertible result
Related: #11, #32
Server version
0.1.12
mcp-ts-core version
0.10.9
Runtime
Bun
Runtime version
1.3.x
Transport
stdio
OS
macOS
Description
ref_timezone_convert silently accepts local datetimes that fall in a DST "spring-forward" gap — a wall-clock moment that never physically occurs because the clock jumps forward (e.g., 02:00 → 03:00 in America/New_York on 2026-03-08). TimezoneService.convert()'s two-step offset refinement (added for #11) picks an
Read the thread · 2026-07-17 · closed · 1 comment
bug(ref_constant_lookup): related[] returns near-identical lists for "constant"-suffixed entries via generic-word token collision
Related: #33
Server version
0.1.12
mcp-ts-core version
0.10.14
Runtime
Bun
Runtime version
1.3.x
Transport
stdio
OS
macOS
Description
ConstantsService.findRelated() (rewritten in #33 to use whole-token name matching) still produces near-arbitrary related[] results for any constant whose name contains the literal word "constant" — 14 of the dataset's 32 entries. Because "constant" is a length-8, non-stopword token shared across all 14, any two of them
Read the thread · 2026-07-17 · closed · 1 comment
enhancement(ref_unit_convert): disambiguate "t" (US short ton) vs "mt" (metric tonne) in description
Use case
ref_unit_convert's description lists mass units as "mcg, mg, g, kg, oz, lb, mt, t" with no gloss. In convert-units, mt = metric tonne (1000 kg) and t = US short ton (907.18 kg). Since t is the common symbol for "tonne" internationally, an agent converting 1 t expecting 1000 kg silently gets 907 kg.
ref_unit_convert { "value": 1, "from": "t", "to": "kg" } → 907.18
ref_unit_convert { "value": 1, "from": "mt", "to": "kg
[Read the thread](https://github.com/cyanheads/reference-data-mcp-server/issues/35) · 2026-06-30 · closed · 1 comment
### enhancement(ref_element_lookup): accept international/IUPAC spellings (Aluminium, Caesium, Sulphur)
### Use case
`ref_element_lookup` resolves American spellings only. The element dataset (`src/data/periodic-table.ts`) stores `Aluminum`, `Cesium`, `Sulfur`, and the name fuzzy-fallback is `storedName.startsWith(query)`, which can't bridge a spelling difference. So the IUPAC-preferred spellings **Aluminium** and **Caesium**, and British **Sulphur**, all fail:
ref_element_lookup { "query": "Aluminium" } → No element matched "Aluminium". ... check the IUPAC name or symbol spelling. ref_eleme
Read the thread · 2026-06-30 · closed · 1 comment
See all 21 reports Pod holds for reference-data-mcp-server — of 39 qualified upstream.
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