Schemav2Validator Plugin
Validates Beckn protocol requests against OpenAPI 3.1 specifications using kin-openapi library.
Features
- Validates requests against OpenAPI 3.1 specs
- Supports remote URL and local file loading
- Automatic external $ref resolution
- TTL-based caching with automatic refresh
- Generic path matching (no hardcoded paths)
- Direct schema validation without router overhead
Configuration
schemaValidator:
id: schemav2validator
config:
type: url
location: https://example.com/openapi-spec.yaml
cacheTTL: "3600"
Configuration Parameters
| Parameter |
Type |
Required |
Default |
Description |
type |
string |
Yes |
- |
Type of spec source: "url" or "file" ("dir" reserved for future) |
location |
string |
Yes |
- |
URL or file path to OpenAPI 3.1 spec |
cacheTTL |
string |
No |
"3600" |
Cache TTL in seconds before reloading spec |
How It Works
- Load Spec: Loads OpenAPI spec from configured URL at startup
- Extract Action: Extracts
action from request context.action field
- Find Schema: Searches all paths and HTTP methods in spec for schema with matching action:
- Checks
properties.context.action.enum for the action value
- Also checks
properties.context.allOf[].properties.action.enum
- Stops at first match
- Validate: Validates request body against matched schema using
Schema.VisitJSON() with:
- Required fields validation
- Data type validation (string, number, boolean, object, array)
- Format validation (email, uri, date-time, uuid, etc.)
- Constraint validation (min/max, pattern, enum, const)
- Nested object and array validation
- Return Errors: Returns validation errors in ONIX format
Action-Based Matching
The validator uses action-based schema matching, not URL path matching. It searches for schemas where the context.action field has an enum constraint containing the request's action value.
Example OpenAPI Schema
paths:
/beckn/search:
post:
requestBody:
content:
application/json:
schema:
properties:
context:
properties:
action:
enum: ["search"] # ← Matches action="search"
Matching Examples
| Request Action |
Schema Enum |
Match |
search |
enum: ["search"] |
✅ Matches |
select |
enum: ["select", "init"] |
✅ Matches |
discover |
enum: ["search"] |
❌ No match |
on_search |
enum: ["on_search"] |
✅ Matches |
External References
The validator automatically resolves external $ref references in OpenAPI specs:
# Main spec at https://example.com/api.yaml
paths:
/search:
post:
requestBody:
content:
application/json:
schema:
$ref: 'https://example.com/schemas/search.yaml#/SearchRequest'
The loader will automatically fetch and resolve the external reference.
Example Usage
Remote URL
schemaValidator:
id: schemav2validator
config:
type: url
location: https://raw.githubusercontent.com/beckn/protocol-specifications/master/api/beckn-2.0.0.yaml
cacheTTL: "7200"
Local File
schemaValidator:
id: schemav2validator
config:
type: file
location: ./validation-scripts/l2-config/mobility_1.1.0_openapi_3.1.yaml
cacheTTL: "3600"
Dependencies
github.com/getkin/kin-openapi - OpenAPI 3 parser and validator
Error Messages
| Scenario |
Error Message |
| Action is number |
"failed to parse JSON payload: json: cannot unmarshal number into Go struct field .context.action of type string" |
| Action is empty |
"missing field Action in context" |
| Action not in spec |
"unsupported action: <action>" |
| Invalid URL |
"Invalid URL or unreachable: <url>" |
| Schema validation fails |
Returns detailed field-level errors |