gRPC

Rostyman supports all four gRPC streaming patterns — Unary, Server Streaming, Client Streaming, and Bidirectional Streaming — with a visual Proto Explorer, a Monaco-based JSON request editor, metadata, authentication, TLS configuration, and a response panel that shows status codes, timing, and stream logs.

Opening a gRPC Tab

Click + New Tab and select gRPC, or open a saved gRPC request from the sidebar. Each tab has its own proto file, selected method, request body, metadata, auth, and TLS configuration.

Layout Overview

The gRPC tab is split into two panels:

Left panel (Proto Explorer, 220px) — import proto files and browse the package/service/method tree
Right panel — the URL bar, sub-tabs (Message, Metadata, Auth, TLS, Settings), and response area

Proto Explorer (Left Panel)

Loading a Proto File

The Proto Explorer header shows Proto Explorer in uppercase. Below it, a path input field and a load button let you import .proto files.

To load a proto file:

Type or paste the absolute file path in the path input, e.g.:
```
/home/user/api/user.proto
C:\projects\api\user.proto
```
Press Enter or click Import Proto

Rostyman parses the file using protobufjs. Relative imports in the proto file are resolved from the same directory as the loaded file, so if user.proto imports common/types.proto, it will be found automatically if it exists at the same path relative to user.proto.

While loading, the button shows Loading... and is disabled. Once parsed, the method tree populates immediately.

Method Tree

The tree shows the full hierarchy from the proto file:

▶ package.name
  ▶ ServiceName
      MethodName   UNARY
      ListMethod   SERVER STREAM
      UploadMethod CLIENT STREAM
      ChatMethod   BIDI STREAM

Packages — top-level namespace from the package declaration
Services — each service block in the proto
Methods — each rpc in a service, with a method type badge

Method type badges identify the streaming mode with distinct colors:

Badge	Color	Pattern
`UNARY`	Green	Single request, single response
`SERVER STREAM`	Cyan	Single request, multiple responses
`CLIENT STREAM`	Yellow	Multiple requests, single response
`BIDI STREAM`	Purple	Multiple requests, multiple responses

Click any method to select it. Rostyman reads the request message's fields and pre-populates the JSON editor with a skeleton object where string fields default to "", booleans to false, and numeric fields to 0.

URL / Config Bar (Right Panel)

The config bar runs across the top of the right panel.

Status Badge

A pill on the left shows the current operation status:

Status	Color	Meaning
idle	Gray	No call in progress
calling	Amber	Unary or client-stream call in flight
streaming	Amber	Server/bidi streaming active
done	Green	Call completed successfully
error	Red	Call failed

Server URL

The server address input accepts host:port without a scheme:

localhost:50051
grpc.api.example.com:443
192.168.1.10:9090

Do not include grpc:// or https:// — TLS is controlled separately in the TLS tab. Environment variables ({{variable}}) are resolved at invoke time.

Selected Method Display

When a method is selected in the Proto Explorer, a pill in the config bar shows ServiceName/MethodName and the streaming mode badge. This is a read-only indicator — to change the method, click a different one in the left panel.

Duration

After a completed Unary or Client Streaming call, the response duration in milliseconds (e.g., 42ms) appears next to the method display.

Invoke / Stop Button

Invoke (Play icon, accent color) — starts the call. Disabled if no method is selected or a unary call is already in flight.
Stop (Square icon, red) — available during Server Streaming or Bidi Streaming. Clicking it sends a disconnect and closes the stream.

Environment Selector

The Environment dropdown controls variable resolution for the server URL, request body, and metadata values.

Save / Save As

Press Ctrl+S (or Cmd+S on macOS) to save. The Save button highlights in the accent color when there are unsaved changes. If the tab has no saved request yet, the Save As dialog appears instead.

Sub-tabs

Five sub-tabs appear below the config bar:

Message Tab

The Message tab contains a full Monaco editor for composing the gRPC request body as JSON.

When you select a method from the Proto Explorer, the editor is pre-populated with a skeleton based on the method's input message fields:

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

Edit the skeleton with your actual values. Environment variables ({{variable}}) in string values are resolved at invoke time.

For Client Streaming, the request body should be a JSON array of message objects — each element is sent as one message in the stream:

[
  { "chunk": "part one" },
  { "chunk": "part two" },
  { "chunk": "part three" }
]

For Bidirectional Streaming, a separate Bidi Send input area appears below the main editor. Use it to send individual messages to the server while the stream is open, without ending it.

Monaco editor features available in the request editor:

JSON syntax highlighting and bracket matching
Line numbers, word wrap, code folding
2-space indentation, no minimap

Metadata Tab

Metadata is the gRPC equivalent of HTTP headers — key-value pairs sent with every call on this request. Common uses include passing authentication tokens, request IDs, and tenant identifiers.

The metadata editor shows a table with three columns:

Column	Description
Enabled checkbox	Toggle a metadata entry without deleting it
Key	Metadata key name (lowercase recommended per gRPC spec)
Value	Metadata value — supports `{{variable}}` substitution

Click + Add to append a new row. Click × to remove a row.

When there are no rows, a "No metadata" placeholder is shown.

Authentication configured in the Auth tab is also injected as metadata at invoke time (see below). Auth metadata takes precedence over manually entered metadata with the same key.

Auth Tab

The Auth tab configures how authentication credentials are injected into the gRPC call. The selected auth type is applied as metadata at invoke time.

Auth Type selector:

Type	Description
None	No authentication. No metadata is injected.
Bearer Token	Injects `authorization: Bearer <token>` as metadata.
API Key	Injects a custom header name with a custom value as metadata.
Basic Auth	Base64-encodes `username:password` and injects `authorization: Basic <encoded>` as metadata.

Bearer Token fields:

Token — the raw token value. Supports {{variable}}.

API Key fields:

Header Name — the metadata key to use (default: x-api-key). Supports {{variable}}.
Value — the API key value. Supports {{variable}}.

Basic Auth fields:

Username — supports {{variable}}.
Password — supports {{variable}}.

All credential values are stored in the tab state and persisted when saved to a collection.

TLS Tab

The TLS tab controls whether the connection uses TLS and how certificates are handled.

Enable TLS (toggle)

When off, the connection is made over plain TCP (insecure). When on, TLS is used and additional options appear.

Default: off.

Skip Certificate Verification (toggle, visible when TLS is enabled)

When on, the client connects without verifying the server's certificate. Useful for local development with self-signed certificates. Do not use in production.

Default: on (when TLS is first enabled).

When Skip Certificate Verification is turned off, three path fields appear for mutual TLS:

Field	Description
CA Certificate Path	Absolute path to the Certificate Authority file used to verify the server's certificate
Client Certificate Path	Absolute path to the client's TLS certificate (for mutual TLS)
Client Key Path	Absolute path to the client's private key (for mutual TLS)

All three path fields accept absolute file system paths. Leave Client Certificate and Client Key empty if you only need server-side TLS (not mutual TLS).

Example for a self-signed CA with client certs:

CA Path:   /etc/ssl/myapp/ca.crt
Cert Path: /etc/ssl/myapp/client.crt
Key Path:  /etc/ssl/myapp/client.key

Settings Tab

The Settings tab provides call-level configuration options.

Setting	Default	Description
Timeout	`30000` ms	Maximum time to wait for a unary or client-stream call to complete. `0` means no timeout. For streaming calls, this is the connection timeout.
Compression	Off	Enable gzip compression for request messages.
Max Message Size	`4` MB	Maximum size of a single received message. Messages larger than this cause a receive error.

Response Panel

After a Unary or Client Streaming call completes, the Response sub-tab becomes active automatically. For Streaming calls, a Stream Log panel appears below the main tab area.

Unary / Client Streaming Response

The Response tab shows:

Status — the gRPC status code and message (e.g., OK, NOT_FOUND, INTERNAL, UNAUTHENTICATED)
Duration — call duration in milliseconds, also shown in the config bar
Response body — the full JSON-formatted response message in a Monaco editor with syntax highlighting
Copy button — copies the response body to clipboard

If the call fails, the response area shows the error message from the gRPC status.

Streaming Response Log

For Server Streaming, Client Streaming, and Bidirectional Streaming calls, a collapsible Stream Log panel appears below the sub-tabs. It shows every stream event in chronological order.

Entry type	Color	Meaning
receive	Blue/accent	A message received from the server
send	Green	A message you sent (bidi streams)
info	Muted	Stream lifecycle events (started, ended, stream ID)
error	Red	Stream errors

Each row shows a timestamp and the full JSON-formatted message. The log auto-scrolls to the latest entry. Click the collapse/expand chevron in the log header to hide the log and give more space to the editor.

Streaming Modes in Detail

Unary

Single request, single response — the standard RPC pattern.

Select a method with no streaming flags in the Proto Explorer
Fill in the request body
Click Invoke
The response appears in the Response tab

Server Streaming

The server returns multiple messages over time after a single request.

Select a method with SERVER STREAM badge
Fill in the request body
Click Invoke — the button changes to Stop
Each response message appears in the Stream Log as it arrives
The stream closes automatically when the server finishes, or click Stop to close early

Client Streaming

The client sends multiple messages, then the server responds once.

Select a method with CLIENT STREAM badge
Write a JSON array in the request body — each array element is one message
Click Invoke
Rostyman sends all array elements as a stream and then signals end-of-stream
The single server response appears in the Response tab

Bidirectional Streaming

Both sides exchange messages simultaneously.

Select a method with BIDI STREAM badge
Fill in the initial request body in the editor
Click Invoke — the connection opens, the initial message is sent, the button becomes Stop
Received messages appear in the Stream Log
Use the Bidi Send input below the editor to send additional messages while the stream is open
Click Stop to close the stream and receive any final response

Saving to a Collection

Press Ctrl+S (or Cmd+S on macOS) to save the gRPC request.

What is persisted:

Server URL
Proto file path
Selected service and method
Request body (JSON)
Metadata rows
Auth type and credential fields
TLS configuration
Settings (timeout, compression, max message size)

Tips

If your proto has import statements, make sure all imported .proto files are in the same directory tree — relative imports are resolved from the loaded file's directory
Use Bearer Token auth with {{token}} and store tokens in your environments — no need to copy-paste tokens into the metadata table
For mutual TLS in development, generate a local CA and client cert with mkcert or openssl, then point the TLS tab at the generated files
The Stream Log retains up to 500 entries per session — long-running streams that produce many messages will rotate old entries out
Unary calls switch to the Response tab automatically; click the Stream Log tab to review streaming results from a previous call

Opening a gRPC Tab​

Layout Overview​

Proto Explorer (Left Panel)​

Loading a Proto File​

Method Tree​

URL / Config Bar (Right Panel)​

Status Badge​

Server URL​

Selected Method Display​

Duration​

Invoke / Stop Button​

Environment Selector​

Save / Save As​

Sub-tabs​

Message Tab​

Metadata Tab​

Auth Tab​

TLS Tab​

Settings Tab​

Response Panel​

Unary / Client Streaming Response​

Streaming Response Log​

Streaming Modes in Detail​

Unary​

Server Streaming​

Client Streaming​

Bidirectional Streaming​

Saving to a Collection​

Tips​