---
title: "Get an attachment"
method: GET
path: "/v1/attachments/{id}"
tags: ["Compatibility"]
---

# Get an attachment

`GET /v1/attachments/{id}`

## Request

- Base URL: `https://api.gunspec.io`
- URL: `https://api.gunspec.io/v1/attachments/{id}`
- Auth: one of:
  - API key in header `X-API-Key`
  - HTTP bearer

One attachment with its requirement groups (any of the standards within a group, every group across groups), what it provides once fitted, its caliber ratings and its stat and spec effects.

Available on every plan. Requires an API key; Explorer keys receive a reduced field set.

## Path parameters

- `id` string, required

## Headers

- `If-None-Match` string

## Response `200`

Get an attachment

- object
  - `success` boolean, required: Always true on a successful response. Every error carries `false` and an `error` object instead.
  - `data` AttachmentDetail, required
    - `id` string: URL-safe slug identifying the part, e.g. `magpul-zhukov-s-stock`.
    - `name` string: Display name, as the maker writes it.
    - `category` string: What kind of part it is: `stock`, `optic`, `muzzle`, `magazine`, `grip`.
    - `manufacturer` ManufacturerRef
      - `id` string: Slug of the manufacturer.
      - `name` string: Display name, as the maker writes it.
    - `modelNumber` string, nullable: The maker's own SKU, where they publish one.
    - `weightG` number, nullable: Weight in grams.
    - `lengthMm` number, nullable: Length in millimetres.
    - `capacity` integer, nullable: Magazines only
    - `boreDiameterMm` number, nullable: Suppressors and muzzle devices
    - `requiresPosition` string, nullable: The mount position this part occupies, or null when it takes none.
    - `isFactoryPart` boolean: True when the part ships on the firearm from the factory. A factory part carries no `statMods` or `specDeltas`, because the firearm's own figures already include it.
    - `factoryFor` string, nullable: The firearm this is the factory part for, when `isFactoryPart` is true.
    - `statMods` object: Editorial adjustments to the game statistics once fitted, keyed by stat. Same status as `game_*` on a firearm: **not measured**.
    - `specDeltas` object: Specification changes once fitted, keyed by field: a folding stock changes the folded length, for example.
    - `imageUrl` string, nullable: Absolute URL of the manufacturer product photo on the assets CDN, ready to render. Null when no photo has been sourced yet.
    - `status` 'in_production' | 'discontinued' | 'limited': Production status of an attachment. `limited` corresponds to a firearm's `limited_production`.
    - `dataConfidence` number, nullable: How completely the record is specified and how well it is sourced, 0 to 1. A record-level completeness and provenance measure, **not** a per-field probability of correctness. Use it to rank and triage; use `sources` to verify an individual number.
    - `updatedAt` string: When a field we serve last changed.
    - `version` string, nullable: Opaque fingerprint of this record. It changes when and only when a field we serve changes, so a client holding the same value already has the record and need not fetch it. Equality is the only supported operation: do not parse it, and do not assume how it is computed. Null means the record has not been written since versioning began, not that it is unchanged.
    - `provenance` Provenance: Where a record's figures came from and how far they have been checked, in one place. `sources` are the pages consulted; check a specific figure against those. `sourceKinds` says what each page is and `bestSourceKind` the strongest of them, on the hierarchy `SourceKind` defines: a maker or standards-body page is evidence for a figure, a retailer or forum page is evidence the item exists. `dataConfidence` is the 0 to 1 score set from what was actually sourced and never raised by hand. `verifiedAt` and `verifiedFields` say when a source was last read against the record and which fields it stated; null means the row is still seed knowledge. `updatedAt` and `version` are the same cache signals the record carries at the top level.
      - `sources` string[], required: The pages consulted when the record was compiled, as an array. Check a specific figure against these rather than against `dataConfidence`.
      - `sourceKinds` object[], required: What each cited page is, in `sources` order, on the `SourceKind` hierarchy. A host not in the source map is `other`, never guessed.
        - `url` string, required: Absolute, directly fetchable URL.
        - `kind` 'manufacturer' | 'standards_body' | 'government' | 'peer_reviewed' | 'reference' | 'aggregator' | 'press' | 'retailer' | 'community' | 'other', required: What kind of page a cited source is, strongest first: the maker's own page, a standards body (SAAMI, C.I.P.), a government or military document, an independent reference work, a specification aggregator, the press, a retailer or auction listing, a community site, or an unclassified page. Weigh a figure by the best kind behind it, never by how many pages were cited.
        - `archivedFrom` string, nullable, required: The original address when `url` is a Wayback Machine capture of it. A cited page that no longer answers is replaced by its last capture that answered 200, so the citation still shows what its author read; `kind` is the original page's.
        - `rank` integer, required: The kind's place in the source hierarchy: 0 is the maker, the strongest; higher is weaker.
        - `tier` 'authority' | 'classified' | 'unclassified', required: Where the site stands in the source registry (`/v1/data/sources`): an authority (the maker, a standards body, a government), a classified site, or one not yet classed.
        - `basis` 'declared' | 'maker' | 'rule' | 'unclassified', required: What the class rests on: classed by a person, a catalogued maker's own site, a .gov or .mil domain, or nothing yet.
        - `evidence` string, nullable, required: The words the site was classed on, where a person recorded them.
      - `bestSourceKind` 'manufacturer' | 'standards_body' | 'government' | 'peer_reviewed' | 'reference' | 'aggregator' | 'press' | 'retailer' | 'community' | 'other', required: What kind of page a cited source is, strongest first: the maker's own page, a standards body (SAAMI, C.I.P.), a government or military document, an independent reference work, a specification aggregator, the press, a retailer or auction listing, a community site, or an unclassified page. Weigh a figure by the best kind behind it, never by how many pages were cited.
      - `makerSource` string, nullable, required: The first cited page on the record's own manufacturer's website, or null when it cites none. A page on another maker's site does not count. Cited from the maker is not the same as checked against it: `verifiedFields` names the figures that were read against a source.
      - `evidence` 'verified' | 'maker' | 'authority' | 'secondary' | 'none', required: How far the record's figures are backed, strongest first, for a badge: `verified` when at least one figure was read against a source (`verifiedFields`), `maker` when it cites a page on its own manufacturer's site (`makerSource`), `authority` when it cites a maker, standards body or government page, `secondary` when it cites only press, retailers, references or forums, `none` when it cites nothing. Derived from the fields beside it.
      - `checks` object: The checks the record has been through, on a single record's response only: every task the data agent (Redback) or a person was given about it, what each proposed, the pages it read, and whether a person accepted it. Nothing an agent proposes reaches the record until a person accepts it, so this is the trail behind `verifiedFields`. Who reviewed is not published; an agent's instance name is.
        - `raised` integer, required: Every task ever raised on the record, answered or not.
        - `open` integer, required: Tasks still waiting to be worked.
        - `history` object[], required: The latest twenty, newest first.
          - `task` string, required: The task id, stable across runs; the same id `/v1/data/tasks/{taskKey}` answers for.
          - `number` integer, nullable, required: The task's number; `/v1/data/tasks/{number}` loads it as its key does.
          - `check` string, nullable, required: The check that raised it, where one did.
          - `kind` string, required: `verify` reads the record against its maker's page, `gap` researches an empty field, `contradiction` judges fields that disagree, `vocabulary` a value outside a list.
          - `agent` string, nullable, required: `redback` when the agent worked it, `staff` when a person did, null when nobody has.
          - `worker` string, nullable, required: The agent instance that worked it; null for a person.
          - `status` string, required: `resolved` (a proposal was filed), `unverifiable` (nothing could be established; retried after a cooldown), `not_a_fault`, or open.
          - `decidedAt` string, nullable, required: When the task was answered; null while it is open.
          - `proposed` string, nullable, required: What it proposed, in its own words; null while it is open.
          - `fields` string[], required: Per-field completeness, keyed by column name.
          - `sources` string[], required: The pages it read and quoted.
          - `review` object, nullable, required: A person's decision on the proposal; null until reviewed.
            - `decision` 'accepted' | 'rejected': Whether a person accepted the proposal.
            - `at` string, nullable: When they decided.
          - `finding` object, nullable, required: What the check found, where a check raised the task: its own line for this record and the figures it measured, so a reader sees how the value breaks the method. The same the public task board serves with `include=research`.
            - `why` string, nullable, required: The check's line for this record.
            - `evidence` object, nullable, required: The figures the check measured.
      - `dataConfidence` number, nullable, required: The 0 to 1 score set from what was actually sourced, never raised by hand. See the confidence bands in the docs.
      - `verifiedAt` string, nullable, required: When a source was last read against this record. Null means the row is still seed knowledge.
      - `verifiedFields` string[], nullable, required: Which fields the source stated, as an array. Everything else on a verified row is still unverified. Null where no source has been read.
      - `specSource` string, nullable, required: Cartridges only: the page the drawing figures were taken from. Null on every other kind of record.
      - `updatedAt` string, required: When a served column last changed; the same value the record carries at the top level.
      - `version` string, nullable, required: The record's content version, equal to the top-level `version`; equal versions mean equal data.
    - `description` string, nullable: Prose summary of the record, where one has been written.
    - `specs` object: Category-specific facts
    - `sources` string[]: JSON array of the pages the figures were taken from, as a string.
    - `sourceUrl` string, nullable: Page the asset or document was taken from.
    - `yearIntroduced` integer, nullable: Year it entered production or service. Null where the date is disputed or unknown.
    - `requires` array[]: Requirement groups. One standard from each group must be present on the firearm. Empty means universal fit.
      - StandardRef[]
        - `id` string: Kind-prefixed standard id.
        - `name` string: Display name, as the maker writes it.
        - `kind` string: What sort of interface it is.
    - `provides` object[]: Standards this adds to the firearm once fitted, resolved to `{ id, name, kind, position }`.
      - `id` string: Kind-prefixed standard id.
      - `name` string: Display name, as the maker writes it.
      - `kind` string: What sort of interface it is.
      - `position` string, nullable: Where on the firearm the standard sits once fitted, when that is not where this part mounts: a side mount clamps to the side rail and puts its Picatinny rail over the receiver. Null means where this part mounts.
    - `caliberRatings` object[]: What this part is rated for, where being rated matters, meaning suppressors and magazines. The caliber, bore and minimum-barrel gate is checked against these and is never bridged or inferred.
      - `caliberId` string: Slug of the cartridge. Resolve against `/v1/calibers/{id}`.
      - `caliberName` string, nullable: Display name of the cartridge.
      - `minBarrelLengthMm` number, nullable: Shortest barrel in millimetres this part is rated for in that cartridge. Null where the maker states none.
      - `fullAutoRated` boolean: Whether the maker rates it for automatic fire in that cartridge.
      - `notes` string, nullable: Free-text notes that do not belong in a specific field.
    - `curatedFits` integer: Number of firearms with a curated override for this attachment
    - `createdAt` string: When the record was first added, `YYYY-MM-DD HH:MM:SS` in UTC.

## Other responses

- `304`: Your copy is current. No body is sent, and this response does not count toward the daily request allowance.
- `400`: Validation error
- `401`: Missing or invalid API key
- `403`: The credential is valid and the caller is not permitted. Three causes, none of which reissuing a key changes: the plan is below the endpoint's tier, the account is suspended, or the key is not attached to the thing being acted on, meaning a user account for `/v1/me` or a shop for `/v1/vendor`. Distinct from 401, which means the credential is missing, malformed or expired and a new one can work.
- `404`: Resource not found
- `429`: A limit was reached. `RATE_LIMITED` is the per-minute limit: wait `Retry-After` seconds (a minute) and retry. `DAILY_CAP_EXCEEDED` is the plan's daily limit, per key: nothing will be served until the counters return to zero at midnight UTC. `MONTHLY_CAP_EXCEEDED` is the plan's monthly allowance, for the whole account: nothing will be served until midnight UTC on the first of next month, or until the plan changes. For both, `Retry-After` is the seconds until then and `error.resetsAt` says when as an instant. Calls made after a refusal are refused too and do not spend the month, and a free key that keeps calling is paused, so stop at the first one and resume at the reset.
- `500`: Internal server error

---

[API](https://skmtc.dev/gunspec/apis/gunspec-io-api.md) · [All operations](https://skmtc.dev/gunspec/apis/gunspec-io-api/llms.txt) · [OpenAPI document](https://skmtc.dev/gunspec/apis/gunspec-io-api/revisions/f2e974d8b05c?raw)