Pulse API Client (Alpha)

Pulse is a performance-focused, local-first, developer-first API client built for modern development workflows. Built with Wails - Go + Svelte + TypeScript!

It unifies classic HTTP testing, gRPC, real-time streaming protocols, and event-driven systems into one clean, fast, desktop-native tool.

Currently fully supports - HTTP, gRPC, Kafka, WebSockets, SSE, gRPC Streams.

This project is actively in development and currently in Alpha.
Breaking changes, UI shifts, and feature overhauls will happen frequently.

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Key Concepts

Unified Workspaces

• Multiple custom workspaces
• Each workspace keeps its own:
  • Environments
  • Variables
  • Collections
  • History
  • UI layout state
• Fully locally persisted and securely encoded

Environments & Variables

• Create unlimited custom environments
• Define variables (string, JSON, secret)
• Variable substitution in URLs, headers, bodies, and streaming tools
• Automatically saved and restored

Collections

• Save HTTP requests, gRPC calls, streaming connections
• Folder support, drag & drop reordering
• Execute saved requests instantly
• Fully persisted on disk

History

• Every request/connection is tracked:
  • Timestamp
  • Method or protocol
  • URL/topic/service
• Encoded local storage ensures fast access and privacy

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Protocol Support (Alpha)

Pulse already supports a wide set of protocols, with more being built.

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1. HTTP Client

Features

• Full request builder:
  • Method, URL, params
  • Headers
  • Authentication helpers
  • Request body (raw, JSON, form-data)
• Syntax-highlighted editors
• Pretty JSON viewer for responses
• Response details:
  • Status code
  • Headers
  • Timing
  • Size
• Save requests to collections
• Fully compatible with environment variables

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2. gRPC (Unary)

Features

• Upload .proto files
• Paste raw proto definitions
• Reflection mode (where server supports it)
• Auto-generate:
  • Services
  • Methods
  • Types
• Editor for request messages
• Response previewer with:
  • Message tree
  • JSON view
  • Raw proto view

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3. Streaming Lab (Unified Streaming Window)

A single tab where every real-time or bi-directional protocol lives together.

Supported right now:

WebSocket

• Custom subprotocols
• Auto reconnect
• Ping/pong settings
• Custom headers
• Send custom messages (JSON, text, binary)
• Color-coded inbound/outbound messages
• Timestamping
• Pausing & filtering message flow

Server-Sent Events (SSE)

• Include credentials (cookies)
• Auto reconnect
• Retry timeout
• Resume from Event ID
• Event-type filters
• Custom headers

gRPC Streaming

• Upload/paste protos or use reflection
• Full stream support:
  • Server streaming
  • Client streaming
  • Bi-directional streaming
• Auto-generated message editors
• Structured message inspector
• Dedicated logs for stream events

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4. Kafka (Alpha)

Full Kafka integration, designed for real developer debugging.

Connection

• Bootstrap servers
• Client ID
• Connection timeout
• SASL authentication:
  • PLAIN
  • SCRAM–SHA-256
  • SCRAM–SHA-512
• TLS/SSL:
  • Custom certs
  • Skip verification option

Topic Explorer

• Auto-loads all topics
• Partition counts
• Refresh button

Consumer Panel

• Consumer groups
• Offset strategies:
  • Latest
  • Earliest
  • Custom offsets
• Auto-commit toggle
• Start/Stop controls
• Live message log:
  • Key
  • Value
  • Headers
  • Timestamp
  • Partition
  • Offset

Producer Panel

• Select topic & partition
• Key & value fields
• Custom headers
• Compression:
  • none
  • gzip
  • snappy
  • lz4
  • zstd
• Acks:
  • 0
  • 1
  • all

Persistence

• All Kafka settings are saved per tab
• Collapsible panels for a clean UI

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Future Roadmap

Coming Soon

• MQTT (WS + backend TCP)
• SSE replay mode
• Secrets manager and 3rd party secrets managers integration
• GraphQL explorer (query editor + schema browser)
• TCP/UDP raw socket inspector
• Redis streams
• PostgreSQL logical replication stream viewer
• gRPC metadata inspector
• AI-assisted request generation
• Multi-window mode
• Plugin system

Planned Later

• Team sync features
• Cloud workspace backup
• Browser extension for capturing requests
• API testing automation runner
• Scripting

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Technology Stack

Frontend

• Svelte + TypeScript
• Wails-native bridge
• Custom JSON viewer
• Monaco-powered editors
• Reactive stores for workspace state

Backend

• Go
• HTTP proxying
• WebSocket/SSE relays
• gRPC client/streaming engine
• Kafka consumer/producer pipeline
• Local encrypted storage

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Alpha Disclaimer

Pulse is not production-ready yet.
Features may break, APIs may change, and a lot of UI polish is still in progress.