JSON Schema Lookup via SchemaStore

Query schemastore.org's catalog of public configuration file schemas to validate structure, discover options, and check allowed values.

API

Catalog: https://www.schemastore.org/api/json/catalog.json
- Structure: { "schemas": [{ "name", "description", "fileMatch", "url", "versions"? }] }
Individual schemas: Fetch the url from the matching catalog entry

Workflow

1. Find the schema

Search the catalog by name or filename pattern:

# Search by name (case-insensitive)
curl -s https://www.schemastore.org/api/json/catalog.json | jq '.schemas[] | select(.name | test("tsconfig"; "i")) | {name, url, fileMatch}'

# Search by filename match
curl -s https://www.schemastore.org/api/json/catalog.json | jq '.schemas[] | select(.fileMatch[]? | test("package\\.json")) | {name, url}'

Alternatively, use WebFetch on the catalog URL and ask for the relevant entry.

2. Fetch and inspect the schema

# List top-level properties
curl -s SCHEMA_URL | jq '.properties | keys'

# Inspect a specific field (type, enum values, description)
curl -s SCHEMA_URL | jq '.properties.FIELD_NAME'

# Check definitions/shared types (schemas use $ref to these)
curl -s SCHEMA_URL | jq '.definitions.DEF_NAME.properties'

# Get the full schema (warning - might be large!)
curl -s SCHEMA_URL | jq .

3. Common queries

# Find enum values for a field
curl -s SCHEMA_URL | jq '.properties.FIELD.enum'

# List nested properties (e.g. compilerOptions in tsconfig)
curl -s SCHEMA_URL | jq '.definitions.compilerOptionsDefinition.properties.compilerOptions.properties | keys'

# Find all required fields
curl -s SCHEMA_URL | jq '.required'

Tips

Some schemas use allOf/anyOf composition -- check those arrays for the full property set
The versions field on catalog entries provides version-specific schema URLs when available
Schema URLs vary: some point to json.schemastore.org, others to raw.githubusercontent.com
For large schemas, query specific paths rather than dumping the entire document
Cache the catalog response locally if making multiple lookups in one session

json-schema-lookup