SDKs

The server-side SDKs that verify Syncanix agent intents on your backend — one per language, across eight ecosystems.

Syncanix generates an agent surface over your existing API — chat inside your app, plus a per-tenant MCP server for Claude, Cursor, and ChatGPT. The agent can run actions with no server-side SDK, under each end user's own identity. Add one when you want your backend to be the last line of defense: a lightweight SDK verifies that every action was genuinely authorized by Syncanix for that tenant and user before you execute it.

What a server-side SDK does

Every Syncanix SDK does one job: verify the signed X-Syncanix-Intent header that rides each inbound tool call. Verification is a fast, local HMAC check against your intent-signing secret — no network round-trip and no shared state.

Confirms the request carries a valid, unexpired intent the Syncanix platform signed — not a forged or replayed call.
Surfaces the acting tenant and end-user (the v2 act-as-user subject) so your handler can scope the action to exactly that user.
Runs entirely in-process: a stateless signature check, with optional single-use replay protection you wire to your own store.

When to add one

You don't need it to ship — the agent chats and runs actions against your discovered endpoints, custom endpoints, and MCP tools under each end user's own identity. Add a server-side SDK when you want a stronger guarantee on actions with side effects — refunds, updates, cancellations: it verifies the signed intent on each call, so a forged or replayed request your platform never authorized can't reach your business logic. Recommended for sensitive writes, not a prerequisite.

Install

Add the SDK for your backend language. Node is set up in the quickstart; the seven other languages each have a dedicated page.

# Node.js (Express, NestJS, Fastify, Next.js)
npm install @syncanix/sdk-node
# Python (Django, Flask, FastAPI)
pip install syncanix-sdk
# Go (net/http, Gin, Echo, Fiber)
go get github.com/syncanix-ai/syncanix-sdk-go
# Spring Boot (JVM)
implementation "ai.syncanix:syncanix-sdk-spring-boot"
# PHP (Laravel, Symfony)
composer require syncanix/sdk-php
# Ruby (Rails, Rack)
bundle add syncanix-sdk-rails
# Rust (Axum, Actix Web, Tower)
cargo add syncanix-sdk-rust
# .NET (ASP.NET Core)
dotnet add package Syncanix.Sdk.AspNetCore

Available at launch — this package is not on its public registry yet, so the command above will work the day Syncanix opens.

Choose your language

Each page walks through installing the package, configuring the intent-signing secret, and a verify-intent snippet in that language's idiomatic framework.

Node.jsExpress, NestJS, Fastify, and Next.js — set up in the quickstart alongside discovery and the widget.PythonDjango, Flask, and FastAPI, via middleware and decorators.Gonet/http, Gin, Echo, and Fiber middleware.Spring BootSpring Boot auto-configuration and a verify-intent annotation.PHPLaravel middleware and a Symfony event subscriber.RubyRails controller concern and Rack middleware.RustAxum, Actix Web, and Tower extractors..NETASP.NET Core Minimal API and MVC, for .NET 8+.

Next steps

Runtime API referenceThe intent envelope, verification rules, and every failure reason — shared by all SDKs.Act as a signed-in userHow the v2 act-as-user flow binds each action to the end-user who requested it.