gRPC

gRPC is a high-performance RPC framework using Protocol Buffers for serialization.

Overview

Service Discovery

Istek supports two ways to discover gRPC services:

1. Server Reflection (Recommended)

If the server has reflection enabled:

1. Select gRPC from the protocol dropdown
2. Enter the server URL: localhost:50051
3. Click Discover

Istek will automatically discover all available services and methods.

2. Proto File Upload

If reflection is not available:

1. Click the Proto button
2. Upload or paste your .proto file
3. Click Parse Proto

URL Format

Format	Description
localhost:50051	Plaintext gRPC
grpc://localhost:50051	Plaintext gRPC (explicit)
grpcs://localhost:50051	gRPC with TLS

note

Istek converts grpc:// to http:// and grpcs:// to https:// internally, as required by the gRPC protocol.

Making a Call

After service discovery:

1. Select a Service from the dropdown
2. Select a Method from the dropdown
3. Edit the JSON message
4. Add any metadata (optional)
5. Click Send

Message Format

gRPC messages are sent as JSON:

{
  "name": "World"
}

Istek converts this to the appropriate protobuf format.

Auto-Generated Samples

When you select a method, Istek generates a sample message based on the input schema:

{
  "name": "",
  "age": 0,
  "active": false
}

Metadata

gRPC metadata is equivalent to HTTP headers. Add custom metadata in the Metadata tab:

Key	Value
authorization	Bearer {{TOKEN}}
x-request-id	{{REQUEST_ID}}

Streaming Types

Type	Badge	Description
Unary	Unary	Single request, single response
Server Streaming	Server Stream	Single request, stream of responses
Client Streaming	Client Stream	Stream of requests, single response
Bidirectional	Bidirectional	Stream of requests and responses

note

Currently, Istek supports Unary calls. Streaming support is planned for future releases.

Response

The response shows:

• Status Code: gRPC status (0 = OK)
• Status Message: Human-readable status
• Response Time: Call duration
• Data: JSON-formatted response
• Metadata: Response metadata/trailers

Status Codes

Code	Name	Description
0	OK	Success
1	CANCELLED	Operation cancelled
2	UNKNOWN	Unknown error
3	INVALID_ARGUMENT	Invalid argument
5	NOT_FOUND	Resource not found
13	INTERNAL	Internal error
14	UNAVAILABLE	Service unavailable

Playground Example

The playground includes a gRPC Greeter service:

URL: localhost:19512

SayHello (Unary)

{
  "name": "Istek"
}

Response:

{
  "message": "Hello, Istek! Welcome to Istek Playground.",
  "timestamp": "2024-01-15T10:30:00Z"
}

Proto Definition

syntax = "proto3";

package playground;

service Greeter {
  rpc SayHello (HelloRequest) returns (HelloReply);
  rpc SayHelloServerStream (HelloRequest) returns (stream HelloReply);
}

message HelloRequest {
  string name = 1;
}

message HelloReply {
  string message = 1;
  string timestamp = 2;
}

Troubleshooting

"Reflection not available"

The server doesn't have reflection enabled. Options:

1. Enable reflection on the server
2. Upload the proto file manually

"Transport error"

• Check if the server is running
• Verify the port is correct
• Ensure you're using the right scheme (grpc:// vs grpcs://)

"Method not found"

• Refresh service discovery
• Check if the service name includes the package (e.g., package.ServiceName)