Enterprise · gRPC

gRPC testing
without the codegen hell.

Load .proto files directly, express payloads as JSON, and test all four gRPC modes — unary, server streaming, client streaming, and bidirectional — with the same Karate syntax you use for REST.

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Also available: Kafka · WebSocket

grpc-test.feature

Feature: User service gRPC tests

Background:
  * host 'grpc.example.com:443'
  * proto 'proto/user.proto'
  * ssl true

Scenario: Create user (unary call)
  Given rpc 'UserService.Create'
  And request
    { name: 'Jane', email: 'jane@test.com' }
  When method grpc
  Then match response ==
    { id: '#number', created: '#notnull' }

Scenario: Server streaming call
  Given rpc 'UserService.ListUsers'
  And request { limit: 10 }
  When method grpc
  Then match each responses ==
    { id: '#number', name: '#string' }

gRPC-Specific Features

First-class gRPC testing

All 4 gRPC Modes

Unary, server streaming, client streaming, and bidirectional streaming — all with the same consistent syntax. No mode-switching boilerplate.

No Code Generation

Point Karate at your .proto files and go. No protoc build step, no generated stubs to commit, no classpath headaches.

Protobuf ↔ JSON

Express requests as plain JSON — Karate handles the binary encoding. Assert against responses with fuzzy JSON matching.

SSL / TLS & Auth

Built-in support for mTLS, bearer tokens, and custom metadata headers. Certificate management handled through standard Karate config.

Mix with REST & Kafka

Test a gRPC call, publish to Kafka, verify the HTTP side-effects — all in the same scenario. Polyglot microservices, unified testing.

Parallel & Perf Testing

Run thousands of gRPC tests in parallel. Reuse the same feature files as Gatling load tests — no separate perf harness.

When to Use gRPC Testing

Perfect for service-mesh teams

Polyglot microservices contracts

Verify service contracts across languages — Go, Java, Python, Node — without language-specific test harnesses.

Bidirectional streaming flows

Test long-lived bidirectional streams like live feeds, chat, or telemetry ingestion — with timing assertions and flow control.

Service mesh & sidecar validation

Validate gRPC traffic through Istio, Linkerd, or Envoy. Assert on headers, retry behavior, and circuit-breaker responses.

API versioning & backward compatibility

Load multiple .proto versions in the same test to verify forward and backward compatibility as schemas evolve.

gRPC testing without the codegen hell.