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The query grammar

GET
/api/query-schema.json

The schema the query surface validates against, as JSON Schema 2020-12 — generated from the validator itself, so it cannot describe a grammar the API does not enforce.

It states its own limits inside itself: nesting depth and the totals counted across a whole request have no JSON Schema vocabulary, so a query this schema admits may still be refused.

This resource answers HEAD as well, with the same headers and no body.

It also answers OPTIONS, which returns Allow, a Link to this description, and — where the resource takes one — the query formats it reads, as Accept-Query.

Response Body

application/json

application/problem+json

curl -X GET "https://example.com/api/query-schema.json"
Empty
---
title: "The query grammar"
description: "The schema the query surface validates against, as JSON Schema 2020-12 — generated from the validator itself, so it cannot describe a grammar the API does not enforce.\n\nIt states its own limits inside itself: nesting depth and the totals counted across a whole request have no JSON Schema vocabulary, so a query this schema admits may still be refused.\n\nThis resource answers `HEAD` as well, with the same headers and no body.\n\nIt also answers `OPTIONS`, which returns `Allow`, a `Link` to this description, and — where the resource takes one — the query formats it reads, as `Accept-Query`."
url: "https://lateano.com/developers/api/reference/discovery/querySchema.get"
author: "Colin Lateano"
---

# The query grammar

The schema the query surface validates against, as JSON Schema 2020-12 — generated from the validator itself, so it cannot describe a grammar the API does not enforce.

It states its own limits inside itself: nesting depth and the totals counted across a whole request have no JSON Schema vocabulary, so a query this schema admits may still be refused.

This resource answers `HEAD` as well, with the same headers and no body.

It also answers `OPTIONS`, which returns `Allow`, a `Link` to this description, and — where the resource takes one — the query formats it reads, as `Accept-Query`.

```json
{
  "openapi": "3.1.1",
  "info": {
    "title": "lateano.com",
    "version": "1.0.0"
  },
  "paths": {
    "/api/query-schema.json": {
      "get": {
        "operationId": "querySchema.get",
        "summary": "The query grammar",
        "tags": [
          "Discovery"
        ],
        "description": "The schema the query surface validates against, as JSON Schema 2020-12 — generated from the validator itself, so it cannot describe a grammar the API does not enforce.\n\nIt states its own limits inside itself: nesting depth and the totals counted across a whole request have no JSON Schema vocabulary, so a query this schema admits may still be refused.\n\nThis resource answers `HEAD` as well, with the same headers and no body.\n\nIt also answers `OPTIONS`, which returns `Allow`, a `Link` to this description, and — where the resource takes one — the query formats it reads, as `Accept-Query`.",
        "parameters": [],
        "responses": {
          "200": {
            "description": "The query grammar",
            "content": {
              "application/json": {}
            }
          },
          "304": {
            "description": "The representation this request already holds is still current, so it is not sent again. No body. Read the validator off `ETag` and send it back as `If-None-Match`.",
            "headers": {
              "etag": {
                "schema": {
                  "type": "string"
                }
              },
              "cache-control": {
                "schema": {
                  "type": "string"
                }
              }
            }
          },
          "default": {
            "description": "Every other status this operation answers with is a refusal, and carries `problem+json` (RFC 9457).\n\nEvery refusal this API can make, whatever the status. Match on the `type` URI’s last segment — the slug below — rather than on the whole URI, which follows whichever deployment answered.\n\n| Status | Slug | Title |\n| --- | --- | --- |\n| 400 | [`invalid-idempotency-key`](https://lateano.com/api/problems/invalid-idempotency-key) | The Idempotency-Key header carries a value this resource will not accept |\n| 400 | [`malformed-body`](https://lateano.com/api/problems/malformed-body) | The request body did not parse |\n| 400 | [`missing-idempotency-key`](https://lateano.com/api/problems/missing-idempotency-key) | This resource requires an Idempotency-Key header |\n| 400 | [`missing-media-type`](https://lateano.com/api/problems/missing-media-type) | The request carried a body with no media type |\n| 404 | [`no-such-resource`](https://lateano.com/api/problems/no-such-resource) | There is nothing at this address |\n| 405 | [`method-not-allowed`](https://lateano.com/api/problems/method-not-allowed) | This resource does not answer that method |\n| 406 | [`not-acceptable`](https://lateano.com/api/problems/not-acceptable) | This resource cannot answer in any media type the request accepts |\n| 409 | [`conflicting-idempotency-key`](https://lateano.com/api/problems/conflicting-idempotency-key) | That Idempotency-Key already names a different submission |\n| 412 | [`precondition-failed`](https://lateano.com/api/problems/precondition-failed) | The condition the request carried does not hold |\n| 415 | [`unsupported-media-type`](https://lateano.com/api/problems/unsupported-media-type) | The request body is in a media type this resource does not read |\n| 422 | [`invalid-query`](https://lateano.com/api/problems/invalid-query) | The query parsed but does not describe a question this resource can answer |\n| 422 | [`invalid-submission`](https://lateano.com/api/problems/invalid-submission) | The submission parsed but is not something this resource can record |\n| 429 | [`too-many-requests`](https://lateano.com/api/problems/too-many-requests) | The courtesy quota for this caller is spent |\n| 500 | [`unexpected-failure`](https://lateano.com/api/problems/unexpected-failure) | The resource failed while answering |",
            "content": {
              "application/problem+json": {
                "schema": {
                  "$ref": "#/components/schemas/ProblemDocument"
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "ProblemDocument": {
        "type": "object",
        "properties": {
          "type": {
            "type": "string",
            "description": "§ 3.1.1. Absolute, on the origin that answered, and it resolves."
          },
          "title": {
            "type": "string",
            "description": "§ 3.1.3. The catalogue row's, unchanged from occurrence to occurrence."
          },
          "status": {
            "type": "number",
            "description": "§ 3.1.2. The same number as the status line, derived rather than passed."
          },
          "instance": {
            "type": "string",
            "description": "§ 3.1.5 RECOMMENDS an absolute URI here. This field carries a full path from the root, which is the fallback form the same section permits."
          },
          "detail": {
            "type": "string",
            "description": "§ 3.1.4. This occurrence only, bounded by `DETAIL_MAX`, absent when there is nothing to add."
          }
        },
        "required": [
          "type",
          "title",
          "status",
          "instance"
        ],
        "additionalProperties": false,
        "description": "The schema generator publishes this declaration as the error schema, so a field here reaches the reference. RFC 9457 § 3.1 makes all five members optional, and this API narrows four of them to required: § 3.1.1 reads an absent `type` as `about:blank` and discards the resolvable URI. An optional member is absent, never present and `undefined`, because `JSON.stringify` drops the value and the wire cannot tell the two apart."
      }
    }
  }
}
```