GunSpec

Compatibility

Fit is computed from mount interfaces, never from names. A firearm declares what it exposes at each position (muzzle thread, rails, optic cut, stock and grip interfaces, magazine well); an attachment declares what it requires; the engine matches the two, through a named adapter where one bridges them. A caliber, bore or minimum-barrel mismatch is never bridged and never inferred.

Every fit carries `source` and `confidence`, and they are the first two fields to read. source is the weakest evidence in the chain that produced the fit; confidence is capped by the weakest interface it went through. The values, strongest first:

  • curated: a person recorded this interface or this fit against the maker's page.
  • universal: the attachment requires nothing (a sling), so every firearm fits it.
  • inherited:parent: the interface came from the firearm's parent record.
  • inherited:platform: the interface came from a platform the firearm belongs to (an AK-100 default, a mil-spec AR-15 default).
  • inferred: the interface was derived by a script from the record's own fields, at 0.6 or below. Convention rows are the weakest inferred evidence and are labelled as such: where a firearm is tagged threaded or optics-ready but names no standard, the backfill applies industry convention (a thread by cartridge and country, an optic plate by the maker's system) at 0.5 to 0.6, with a convention: note on the interface row.

A retailer or an engineering consumer should treat `inferred`, and anything below a confidence they choose, as unverified. Pass min_confidence to hide fits computed through interfaces below that figure; nothing in a response presents an inferred or convention row as verified, and neither should a product page built on it. via[] names each interface the fit went through with its own source, so a fit can be audited hop by hop; GET /v1/firearms/{id}/interfaces lists every row with its source, confidence and inheritedFrom.

Browsing the catalog (/v1/attachments, /v1/attachments/{id}, /v1/interfaces) is open to any key. Everything that answers "does this go on that" is Studio, and a lower plan receives 403 SUBSCRIPTION_REQUIRED rather than an empty list, so never read an error as "nothing fits". fits= on the attachment list is the same computation wearing a query parameter and is gated the same way.

Auth RequiredStudio+

List firearms exposing a standard

Every firearm that exposes the interface standard, directly or through a platform, confirmed through the resolver so a member that has declared none for the position is not listed. The id is URL-encoded: thread%3A1%2F2x28.

GET/v1/interfaces/{id}/firearms

Studio+

  • stringheaderrequired

    Your API key. Authorization: Bearer <key> is accepted in its place.

  • stringrequired

    Interface standard id. URL-encode it in the path: the colon and any slash must be escaped, so thread:1/2x28 is sent as thread%3A1%2F2x28

    Accepts
    a kind-prefixed standard id such as thread:1/2x28
    Example

  • integerdefault1

    Page number, from 1 to 10,000

    Range
    1 – 10000
    Example
  • integerdefault20

    Items per page (max 100)

    Range
    1 – 100
    Example

application/json

  • object[]

    One page of results

  • string

    Slug of the firearm exposing the standard.

  • string

    Display name, as the maker writes it.

  • string

    Where on the firearm the interface sits: muzzle, rear, top, bottom.

  • InterfaceSource

    Where an interface row on a firearm came from. curated is a person; inferred is the backfill, capped at 0.6 confidence; the inherited kinds came through the parent chain or a platform.

  • number

    How well evidenced this row is, 0 to 1. A minimum, not an average: an inferred row caps every fit computed through it, and min_confidence on the endpoint hides rows below a threshold.

  • ManufacturerRef | null

    Who makes it.

  • string | null

    Display name of the firearm category.

  • InlineMediaItem[]

    Renders and photographs of the firearm, ordered so images[0] is the frame to show at rest.

  • integer

    Autoincrementing image id.

  • string

    Absolute, directly fetchable URL.

  • MediaKind

    What kind of asset a media row is.

  • string | null

    Alt text, where one has been written. Null otherwise, so do not render an empty string.

  • integer | null

    Pixel width, where it is known.

  • integer | null

    Pixel height, where it is known.

  • string | null

    Line-art silhouette, or null where none has been drawn.

  • integer

    Year it entered production or service. Null where the date is disputed or unknown.

  • number

    Current page number

  • number

    Items per page

  • number

    Total matching records (Builder and above)

  • 400VALIDATION_ERRORValidation error
  • 401UNAUTHORIZEDAPI key required
  • 403FORBIDDENValid key, not permitted
  • 404NOT_FOUNDResource not found
  • 429RATE_LIMITEDRate limit exceeded
  • 500INTERNAL_ERRORUnexpected server error

Full rate limits

Minimum tier
Studio+
Monthly quota
150,000/mo
Rate limit
120/min
Daily cap
10,000

Figures shown are for this endpoint's minimum tier. Higher tiers raise every limit.