---
summary: Developer guide for choosing real SigID SDK packages and examples–start drop-in first, then framework adapters, then @sigid/client–without inventing non-existent packages.
tags:
  - developers
  - sdks
  - examples
  - integration
categories:
  - For Developers
---

# SDKs And Examples

<!-- agent:page
You are a coding agent choosing the right SigID package for the user's runtime before integrating.
CRITICAL: Prefer @sigid/start (cdn.sigid.org/v1/sigid.js) for plain HTML or any app that can host a script tag. Prefer framework packages only when SSR/cookies/route handlers are required. Prefer @sigid/client only for explicit protocol control or token validation helpers.
ONLY install packages that exist: @sigid/start, @sigid/client, @sigid/react, @sigid/next, @sigid/svelte, @sigid/sveltekit, @sigid/cli. Backend: sdks/go, sdks/rust, sdks/elixir. Do NOT invent @sigid/vue, @sigid/solid, @sigid/solidstart, @sigid/expo, or @sigid/electron.
Cold agents: npx @sigid/cli setup → paste start_snippet. Then follow the matching quickstart. Never hand-roll OAuth for interactive login.
-->

Use this page when you need to pick the package closest to your app runtime.

**Default for interactive login:** hosted helpers (`@sigid/start` or a framework
package). Use low-level `@sigid/client` OAuth helpers only when you need full
protocol control.

## Start By Runtime

| Runtime | First guide | First package |
|---|---|---|
| Plain HTML / static site | [Add Login](add-login.md) (zero-build) | **`@sigid/start`** / CDN `sigid.js` |
| React SPA | [React SPA Quickstart](quickstart-react-spa.md) | `@sigid/react` (+ `@sigid/client`) |
| Next.js App Router | [Next.js Quickstart](quickstart-nextjs.md) | `@sigid/next` |
| Svelte SPA | [Add Login](add-login.md) | `@sigid/svelte` |
| SvelteKit | [Add Login](add-login.md) | `@sigid/sveltekit` |
| Backend API only | [Backend API Quickstart](quickstart-backend-api.md) | validate tokens; no browser SDK required |
| Cold agent / CLI | [Agent Self-Serve Quickstart](agent-quickstart.md) | `@sigid/cli` / `sigid-cli` |
| Local lab | [Run The Example App](run-example-app.md) | `examples/sdk-lab-next` |
| Third-party agent checklist | [Integrate Third-Party App](integrate-third-party.md) | start → framework → client |

## Package Tiers

```text
@sigid/start          # two-line browser drop-in (prefer for simple UIs)
    ↓ uses
@sigid/client         # full browser OAuth/session engine
    ↑ wrapped by
@sigid/react|next|svelte|sveltekit   # framework glue (SSR, cookies, hooks)
```

| Runtime | Package | Use it for |
|---|---|---|
| Any browser (no build) | **`@sigid/start`** | CDN script, declarative `data-sigid` UI, inline callback |
| Browser TypeScript | `@sigid/client` | `createSigIdClient`, login/callback, `validateAccessToken` |
| React | `@sigid/react` | Provider, hooks, sign-in buttons on top of client |
| Next.js | `@sigid/next` | Route handlers, cookies, `requireAuth` / `requireAccessToken` |
| Svelte | `@sigid/svelte` | Stores and actions for SPA-style Svelte |
| SvelteKit | `@sigid/sveltekit` | Hooks, cookies, server handlers |
| CLI / agents | `@sigid/cli` | npm wrapper for native `sigid-cli` (`setup`, device flow, …) |

## Backend SDKs

| Runtime | Directory | Use it for |
|---|---|---|
| Go | `sdks/go` | Go services, CLIs, infrastructure tooling |
| Rust | `sdks/rust` | Rust services and security-sensitive integrations |
| Elixir | `sdks/elixir` | Phoenix / BEAM services |

For languages without an official SDK, use standard OAuth/OIDC libraries plus
discovery and [Verify Access Tokens](verify-tokens.md).

## What Does Not Exist (Do Not Install)

These names appear in older drafts or wishlists. They are **not** published
packages:

- `@sigid/vue`, `@sigid/solid`, `@sigid/solidstart`
- `@sigid/expo`, `@sigid/electron`

Use `@sigid/start` or `@sigid/client` instead until a first-party adapter ships.

## Drop-In Script (Preferred Zero-Build Path)

```html
<script
  src="https://cdn.sigid.org/v1/sigid.js"
  data-client-id="YOUR_CLIENT_ID"
  data-issuer="https://auth.sigid.org"
></script>
<a href="#" data-sigid="login">Sign in</a>
```

- Canonical CDN: `https://cdn.sigid.org/v1/sigid.js`
- Mirror: `https://www.sigid.org/v1/sigid.js`
- npm: `import { createSigIdStart } from "@sigid/start"` (side-effect free; no auto-init)
- Example: `examples/sigid-start/`

Framework apps that already use React/Next/SvelteKit should use the matching
package for SSR and cookies. You can still load start on a static marketing page
of the same product.

## Example Apps

| Example | Path | Notes |
|---|---|---|
| Drop-in start | `examples/sigid-start/` | Canonical two-line demo |
| Next quickstart | `examples/next-app/` | `@sigid/next` + client |
| SvelteKit | `examples/sveltekit/` | hooks + protected page |
| SDK Lab Next | `examples/sdk-lab-next/` | Full golden path (client-centric) |
| Demo | `demo/` | start vs client profile modes |

## Recommended Order

1. [Integrate Third-Party App](integrate-third-party.md) if you are an agent wiring a foreign repo.
2. Runtime quickstart or zero-build start snippet.
3. [Verify Access Tokens](verify-tokens.md) on the backend.
4. [Protect Backend APIs](protect-apis.md).
5. [Webhooks](webhooks.md) / [Commerce](commerce.md) / [Agent quickstart](agent-quickstart.md) only if needed.

## API Schemas

- Public integrator OpenAPI: committed `openapi-public.json`; production may serve
  `GET /openapi.json` with `openapi.exposure = "public"`.
- Full internal OpenAPI is for non-production diagnostics only.

Continue to [API And SDK Reference](../reference/api-sdk-reference.md).