Limited Protobuf Message to JSON Schema

Map supported fields from one protobuf message to a Draft 2020-12 JSON Schema outline.

Protobuf To Json Schema · Client runtimeSandboxed

Protobuf To Json Schema Input

Protobuf To Json Schema Output

Formatted results will render here in real time.

Protobuf To Json Schema: JavaScript is required to run this tool in the browser.

About this limited protobuf message to json schema

Map supported fields from one protobuf message to a Draft 2020-12 JSON Schema outline Validates and converts interface schemas client-side without transmitting private endpoint specifications.

API contract & interface schema logic

Parses one limited protobuf message declaration, maps supported scalar fields to JSON Schema Draft 2020-12 properties, and adds an int32 format hint. It does not emit required for proto3 scalar fields or implement full .proto semantics.

Worked schema conversion scenario

Scenario: A gRPC microservice developer converts a Protocol Buffers `.proto` message into a JSON Schema.

Sample input:

message UserProfile { string user_id = 1; string display_name = 2; int32 age = 3; }

Processing: Parse this limited message declaration and map string fields to strings and int32 to integer with a format hint. Proto3 fields are not automatically required.

Illustrative output:

{ "$schema": "https://json-schema.org/draft/2020-12/schema", "title": "UserProfile", "type": "object", "properties": { "user_id": { "type": "string" }, "display_name": { "type": "string" }, "age": { "type": "integer", "format": "int32" } } }

Schema version & syntax constraints

Only the first message is converted. Custom message references are emitted but not defined; oneof, maps, options and full proto syntax are not resolved.

API specifications and schema models in Limited Protobuf Message to JSON Schema reflect OpenAPI and JSON Schema standards. Verify generated schemas against your runtime validator.

Client-side schema processing boundary

Schema analysis and protocol mapping in Limited Protobuf Message to JSON Schema execute locally in the browser tab without uploading endpoint definitions.

OpenAPI Specification & JSON Schema standards

OpenAPI Specification standards and JSON Schema draft definitions:

JSON Schema Core and Validation (Draft 2020-12)
Protocol Buffers Language Specification (proto3)

Limited Protobuf Message to JSON Schema verification · Audit standards

How to use it

Paste a protobuf message definition.
Read the first message and map supported field types and repeated markers to JSON Schema properties.
Copy the draft 2020-12 schema JSON.

Frequently asked questions

How does Protobuf to JSON Schema build a schema?+

It reads the first message declaration, recognizes a limited set of field types and repeated fields, and creates a Draft 2020-12 object schema with title, properties, and mappings for string, int32, bool, bytes and arrays.

Can you show an input and its result?+

A User message with string id, int32 age, and repeated string roles produced a Draft 2020-12 object schema with id string, age integer format int32, and roles as an array of strings.

Which protobuf constructs have boundaries?+

Only the first message is read. `map`, `oneof`, `enum`, `service`, and `extend` are rejected. Unknown types become `#/$defs/TypeName` references without emitted `$defs`; packages, imports, nested messages, options, proto2 required rules, field presence, and wire data are not fully modeled.

Is the JSON Schema a wire-compatibility guarantee?+

No. It is a structural draft from selected declaration syntax. It does not encode protobuf binary serialization, tag compatibility, default values, unknown-field behavior, generated code, or validation by a protobuf compiler.