SDK Overview¶

Nexus ships three first-class client SDKs. Each provides identical functionality — choose the one that matches your application's language.

Choose Your SDK¶

GoTypeScriptPython

Best for: Go services, agents, and MCP servers built with mcp-go.

go get github.com/Prescott-Data/nexus-framework/nexus-sdk@latest

→ Go SDK Reference

Best for: Node.js services, Next.js apps, and MCP servers built with the MCP TypeScript SDK.

npm install @dromos/nexus-sdk

→ TypeScript SDK Reference

Best for: Python services, FastAPI apps, and MCP servers built with the MCP Python SDK. Zero dependencies.

pip install nexus-sdk

→ Python SDK Reference

Feature Parity Matrix¶

All three SDKs expose the same capabilities:

Feature	Go	TypeScript	Python
`RequestConnection`	✅	✅	✅
`CheckConnection`	✅	✅	✅
`GetToken` (by connection ID)	✅	✅	✅
`RefreshConnection`	✅	✅	✅
`WaitForActive`	✅	✅	✅
`ResolveToken` (workspace + provider)	✅	✅	✅
Token Cache (TTL-aware)	✅	✅	✅
Auth Injection	`RoundTripper`	`createFetcher`	`authenticated_fetch`
Retry + Exponential Backoff	✅	✅	✅
Structured Errors	✅	✅	✅
MCP stdio-safe logging	—	✅ (stderr)	✅ (stderr)
Runtime Dependencies	0	2	0

Two Workflows¶

The SDKs support two distinct usage patterns:

1. Standard App Workflow¶

For backend services that manage OAuth connections on behalf of users. The full connection lifecycle:

request_connection() → redirect user → wait_for_active() → get_token()

2. MCP Server Workflow¶

For MCP servers that need to make authorized API calls on behalf of a workspace/tenant. Token management is fully automated:

createFetcher() / authenticated_fetch() / AuthenticatedHTTPClient()
    → auto-resolves token from gateway
    → caches with TTL
    → injects Authorization: Bearer header
    → makes API call

See the MCP Integration Guide for end-to-end walkthroughs in all three languages.