ALTER Identity SDK

What is ALTER Identity SDK?

A thin client over the ~Alter MCP server (Streamable HTTP, JSON‑RPC 2.0, MCP spec 2025‑11‑25) with x402 micropayment support and ES256 provenance verification. It queries the continuous identity field from any JavaScript/TypeScript environment (Node 18+, Deno, Bun, Cloudflare Workers, modern browsers) and includes config generators for Claude Code, Cursor, and generic MCP clients.

How to use ALTER Identity SDK?

Install with npm install @truealter/sdk. Import and construct an AlterClient or MCPClient with an optional signing parameter for production use. For day‑to‑day commands use the separate CLI (@truealter/cli). A stdio bridge entrypoint is available for host demos but lacks per‑invocation signing; production deployments should import the SDK directly.

Key features of ALTER Identity SDK

• Thin client over ~Alter MCP server with x402 micropayments
• ES256 provenance verification for signed responses
• 37 tools: 28 free (L0) + 9 premium (L1‑L5)
• Minimum‑version preflight with signed floor document
• Three identity headers for server‑side floor enforcement
• Works in Node 18+, Deno, Bun, Cloudflare Workers, modern browsers
• Dual ESM + CJS output, minimal dependencies

Use cases of ALTER Identity SDK

• Verify registered identities by handle, email, or id
• Assess trait signals from text or full 33‑trait vector
• Compute belonging probability for a person‑job pairing
• Get match recommendations or explain matches with narrative
• Search identities by trait criteria without exposing PII

FAQ from ALTER Identity SDK

How does authentication work with ALTER Identity SDK?

Free L0 tools are anonymous. For premium or member actions, run alter login to provision your member credential into the local session (~/.config/alter/session.json) or pass the session credential as the apiKey option when constructing the client.

What is the difference between the stdio bridge and the direct SDK?

The stdio bridge is a dev/demo surface for MCP hosts that speak stdio transport. It does not carry ES256 per‑invocation signing, so authenticated MCP tools fail at the server edge. For production, import the SDK directly and use the optional signing parameter to receive the provenance envelope end‑to‑end.

Why is ~Alter not IAM?

IAM answers “who is logged in”. ~Alter answers “who they actually are” — a continuous field of recognition that any IAM stack can sit on top of.

What is the minimum‑version preflight and how does it work?

The backend publishes a signed per‑client minimum version floor. The SDK preflights this floor lazily on the first network call. If the running SDK is below the floor, it throws BelowFloorError carrying a upgrade_cmd. The check can be run explicitly or left automatic; disabling it is discouraged because the server still rejects below‑floor clients.

What identity headers does the ALTER Identity SDK send?

Every outbound request carries three mandatory headers: