Insomnia

Overview

Insomnia (owned by Kong) is a popular open-source alternative to Postman with a cleaner UI and better GraphQL/gRPC support. Its Git Sync feature stores workspaces in your own repository, addressing privacy concerns about cloud-synced API credentials.

Key Features

GraphQL Explorer:

• Auto-discover schema via introspection
• IntelliSense for queries and mutations
• Variable editor with JSON validation

# Insomnia sends the request and shows formatted results
query GetUser($id: ID!) {
  user(id: $id) {
    id
    name
    email
    orders {
      id
      total
      status
    }
  }
}

Environment Variables:

{
  "base_url": "https://api.example.com",
  "token": "Bearer {{ _.auth_token }}",
  "api_version": "v2"
}

Request Chaining (via Response references):

Request 1: POST /auth/login → saves token to env
Request 2: GET /profile → uses {{ response.body.access_token }}

inso CLI for CI

npm install -g insomnia-inso

# Run a test suite from a collection
inso run test "My API Tests" \
  --env "Production" \
  --ci

# Export collection for sharing
inso export spec "My API" --output openapi.yaml

# GitHub Actions
- name: Run API Tests
  run: inso run test "Integration Tests" --env staging --ci

Insomnia vs Postman vs Bruno

Feature	Insomnia	Postman	Bruno
Open source	✅	❌	✅
GraphQL	Excellent	Good	Good
gRPC	✅	✅	❌
Git-based storage	✅ (paid team)	❌	✅ (native)
Test scripting	Basic	Full JS	Basic
Offline collection format	Proprietary JSON	Proprietary JSON	Markdown-like

Use Cases

• GraphQL API development: Insomnia’s GraphQL support is the strongest among GUI API clients. It auto-discovers the schema via introspection, provides field-level autocomplete in the query editor, and displays response data in a readable tree format. Teams building or consuming GraphQL APIs find it significantly faster than Postman for this workflow.

• gRPC service testing: Unlike Bruno and most other alternatives, Insomnia supports gRPC natively — import a .proto file, browse available services and methods, and call them with a form-based interface. This makes it the go-to tool for backend teams who work with microservices that mix REST and gRPC endpoints.

• Multi-environment API testing: Insomnia’s environment system lets you define base_url, auth tokens, and any number of variables per environment (local, staging, production). Switching environments is a single dropdown — useful when you’re tracing a bug that only reproduces in staging by running the exact same request sequence across environments.

• Design-first API workflows: Insomnia supports importing OpenAPI specs and using them as the source of truth for your request collection. When the spec updates, re-import to sync. This keeps your test collection aligned with your API contract without manually recreating requests.

• Small team collaboration without SaaS overhead: Teams comfortable with Git can use Insomnia’s Git Sync to share collections in a private repository. The free tier handles solo development; Git Sync covers small teams who already have a Git workflow and don’t want to pay for Postman’s workspace tiers. Each developer clones the repo and their Insomnia workspace stays current via git pull.