Need help with your APIs? I offer API discovery, governance & evangelism services. Explore services →
API Evangelist API Evangelist
Discovery
Learnings
Guidance
Toolbox
Alignment
API Evangelist LLC
Thunder Client website screenshot

Thunder Client

Thunder Client is a lightweight REST API client extension for Visual Studio Code created by Ranga Vadhineni, providing a clean interface for sending HTTP requests, managing collections, and testing APIs without leaving the editor. With nearly 7 million installs, it pioneered GUI-based API testing in VS Code with 100% local storage, scriptless testing, Git Sync for team collaboration, GraphQL support, and an advanced CLI for CI/CD integration. Thunder Client supports importing collections from Postman, Insomnia, Hoppscotch, and OpenAPI 3.0, and offers pre/post-request scripting and environment variables.

human only

Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.

Kin Score

API Evangelist profiles Thunder Client the way a machine reads it — 14 machine-readable artifacts across 2 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.

Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Thunder Client scores 43.4/100 (thin), with a separate agent-readiness read of 7/100 (human only). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.

Kin Score

This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 43.4/100 · thin
Contract Quality 5.2 / 25
Developer Ergonomics 1.7 / 20
Commercial Clarity 10.0 / 20
Operational Transparency 6.8 / 13
Governance 10.4 / 12
Discoverability 9.3 / 10
Agent readiness — 7/100 · human only
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 15
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3

How we profile Thunder Client

Each block below is one kind of artifact we hold for Thunder Client. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.

APIs 2

Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.

Individual APIs this provider publishes, each with its own machine-readable definition.

Thunder Client

Thunder Client is the flagship VS Code REST API client extension offering a lightweight GUI for sending HTTP requests, managing collections with environment variables, and runni...

Thunder Client CLI

The Thunder Client CLI (@thunderclient/cli) is a Node.js command-line tool for running Thunder Client requests, collections, and cURL commands from the terminal. It supports CI/...

GraphQL 1

Where a provider ships GraphQL, the schema is the contract. We profile it alongside the REST surface so the whole interface is legible in one place.

GraphQL schemas published by this provider.

Thunder Client GraphQL API

Thunder Client is the flagship VS Code REST API client extension offering a lightweight GUI for sending HTTP requests, managing collections with environment variables, and runni...

GRAPHQL

Pricing Plans 1

Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the six things the Kin Score reads for commercial clarity.

Published pricing tiers and plan structures.

Rate Limits 1

Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.

Documented rate limits and quota policies.

Thunder Client Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.

Cost, billing, and metering signals for API financial operations.

Semantic Vocabularies 1

JSON-LD contexts give the data shared meaning across APIs. We profile them because semantics are what let a machine reconcile 'customer' here with 'customer' somewhere else.

JSON-LD contexts and semantic vocabularies used across these APIs.

Thunder Client Context

14 classes · 27 properties

JSON-LD

Spectral Rules 1

Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.

Thunder Client API Rules

6 rules · 4 warnings

SPECTRAL

JSON Schema 2

Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.

Standalone JSON Schema definitions for this provider's data models.

Thunder Client Collection

7 properties

JSON SCHEMA

Thunder Client Environment

5 properties

JSON SCHEMA

JSON Structure 1

JSON Structure captures the data shapes in a form built for tooling — a complement to JSON Schema that keeps the model machine-legible.

JSON Structure definitions describing this provider's data shapes.

Thunder Client Collection Structure

0 properties

JSON STRUCTURE

Examples 2

Real request and response payloads are what turn a spec from abstract into obvious — and they're one of the twelve things an agent needs to call an API correctly on the first try.

Example request and response payloads for these APIs.

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Thunder Client Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Resources

Every other property we hold for Thunder Client — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.

Documentation 3

Reference material describing how the API behaves

Design & Contract 3

Pagination, idempotency, versioning, errors, and events

Build 3

SDKs, sample code, and the tooling you integrate with

Access & Security 1

Authentication, authorization, and security posture

Operate 1

Status, limits, changes, and where to get help

Commercial 1

Pricing, plans, and the legal terms of use

Company 2

The organization behind the API

← All providers · Data indexed from github.com/api-evangelist/thunder-client · machine-readable index on apis.io