NewJarDocs 1.0: docs that track your code

Tools, Talent & Content for Developers

DeveloperJar is one place for everything developer: free tools and APIs to build with, skilled developers you can hire as a resource for your own company, and practical content written by engineers who ship code. One jar, everything a developer (or a company that needs one) could need.

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Trusted by engineering teams at

  • Northwind Labs
  • Kestrel
  • Paperplane
  • Halcyon
  • Orbitly

What We Build

Built with one standard: it should make your next commit, or your next hire, easier than your last.

Developer Tools

Focused utilities for the jobs you repeat every day: formatting, mocking, inspecting, deploying.

$ jar format --write
✓ 148 files formatted in 0.4s
$ jar lint
✓ no issues found
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Developer Resources

Tutorials, guides and copy-paste snippets written by the engineers who ship the code.

Tutorial · Mock an API in 10 min10 min
Guide · API versioning14 min
Snippet · retry with backoffJS
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APIs

Documented REST and GraphQL APIs with typed SDKs, predictable errors and versioning that doesn’t surprise you.

GET /v1/mocks200
POST /v1/monitors201
DELETE /v1/mocks/:id204
See our APIs

Software Products

Full products for teams, from deployment to observability to secrets, that scale from side project to enterprise.

Deploys per week, last 10 weeks
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Products developers keep installed

A few of the tools and platforms our community uses every day.

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NewDocumentation

JarDocs

Docs that stay in sync with your code.

Generate API and library reference straight from source, publish versioned docs and ship changelogs automatically.

  • Reference generated from source
  • Versioned docs and changelogs
  • Built-in instant search
  • Node.js
  • MDX
  • Git
Free for open sourceTeam $29/mo
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PopularAPIs

JarAPI

Mock, test and monitor any API.

Spin up realistic mock APIs from an OpenAPI spec in seconds, then monitor the real thing using the same collection.

  • Instant mocks from OpenAPI
  • Contract tests in CI
  • Latency and uptime monitors
  • Go
  • OpenAPI
  • Redis
  • TypeScript
FreePro from $19/user/mo
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Developer Tools

SnippetJar

Your team’s snippet library, wherever you type.

Save, search and share code snippets across your editor, terminal and browser, with offline-first sync.

  • VS Code and JetBrains plugins
  • Fuzzy search with tags
  • Shared team collections
  • TypeScript
  • Rust
  • SQLite
FreeTeam $6/user/mo
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Need a developer, not just a tool?

Hire a DeveloperJar engineer as a dedicated resource for your team, vetted, ready fast, and billed the way that suits you.

Talk to us about hiring

Pre-vetted engineers

Every developer is screened for skill and communication before they ever join a client team.

Flexible engagement

Part-time, full-time or project-based. Scale a single hire into a full squad, or back down, as your roadmap changes.

Direct collaboration

Your hire works inside your tools and your sprints, not behind a wall of account managers.

Why DeveloperJar?

We’re developers too. These are the promises we hold every product, API and engagement to.

Read our story

Fast by default

Sub-100 ms API responses, lean CLIs and pages that load before you finish blinking. We test for speed the same way we test for bugs.

Docs written by engineers

Every product ships with a quickstart, a reference and runnable examples. If something needs a support ticket, we treat the docs as the bug.

Privacy-first, opt-in telemetry

Your code and data stay yours. We collect nothing you haven’t agreed to, and we tell you exactly what.

Open where it counts

SDKs, CLIs and schemas are open source, so you can read, fork and trust what runs in your pipeline.

Predictable pricing

Public plans, generous free tiers and no “contact sales” surprises when your usage grows.

Humans on support

Engineers answer your questions, usually within one business day. No bots, no ticket ping-pong.

Learn something useful today

Practical tutorials, guides and snippets, free to read and free to copy.

All resources
SnippetJavaScript

Retry with exponential backoff

A small, dependency-free retry helper with jitter for flaky network calls.

JavaScript
async function retry(fn, { retries = 4, base = 300 } = {}) {
  for (let i = 0; ; i++) {
    try { return await fn(); }
    catch (err) {
      if (i >= retries) throw err;
      const wait = base * 2 ** i + Math.random() * 100;
      await new Promise(r => setTimeout(r, wait));
    }
  }
}
  • JavaScript
  • Reliability

Loved by the people who build with it

“We replaced three internal scripts with JarAPI mocks. New engineers are productive on day one instead of day five.”
Priya NairStaff Engineer, Northwind Labs
“The docs are the first thing I check when evaluating a vendor. DeveloperJar’s are the ones I actually read.”
Marcus FeldCTO, Kestrel
“Preview environments cut our review cycle from days to hours. It’s the tool nobody wants to go back from.”
Aiko TanakaEngineering Manager, Paperplane

Bring DeveloperJar to your team

Whether you need a tool, a hire, or a whole product built, we’d love to hear what you’re working on.

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