Use Credentials with the SDK

Author Credential Provider lifecycles and consume protected credentials through governed Resources without reading secret material.

There are two SDK boundaries: provider code manages lifecycle; Agent code consumes only a governed Resource.

Provider code

import { credentialProvider } from "@constal/sdk";

export default credentialProvider({
  id: "example-token", version: "1.0.0", displayName: "Example token",
  description: "Mints a short-lived token.", credentialSlots: ["bootstrap-token"],
  configSchema: { type: "object", additionalProperties: false },
  credentialConfigSchema: { type: "object", additionalProperties: false },
  rotation: { mode: "manual", intervalMs: null, overlapMs: 0, maxAgeMs: null, refreshBeforeMs: 0 },
  egress: { rules: [] }, mintRecovery: { kind: "outcome-unknown" },
  async mint(_request, context) {
    const bootstrap = await context.secret("bootstrap-token");
    return { material: bootstrap.value };
  },
});

Agent code

const profile = await ctx.invoke(
  ctx.resources.github!, "user.get", {}, { timeoutMs: 30_000 },
);

Ctx has no secret method. The protected integration declares the Credential slot it consumes, and Constal supplies the active version only after binding and Policy resolution. Scoped bindings can select tenant-, customer-, or principal-specific authority before Run admission. Provider-private state and consumer material remain separate; public APIs expose fingerprints and lifecycle state, never bytes. Continue with Build a Credential Provider and Use a credential from an agent.