request headers from inside a custom database adapter

import { betterAuth } from "better-auth";
import { createAuthMiddleware, APIError } from "better-auth/api";

// Define your auth instance with a before hook
export const auth = betterAuth({
  hooks: {
    before: createAuthMiddleware(async (ctx) => {
      // Extract the tenant header from the request headers (e.g., "X-Tenant-ID")
      const tenantId = ctx.headers.get("X-Tenant-ID");
      if (!tenantId) {
        throw new APIError("BAD_REQUEST", { message: "Missing tenant header" });
      }

      // Retrieve tenant-specific configuration (for example, a connection string)
      // This is a placeholder function; in a real app, replace it with your own logic.
      const tenantConfig = await getTenantConfig(tenantId);

      // Inject the tenant configuration into the context.
      // Now the adapter and other parts of Better Auth can use ctx.context.tenantConfig.
      return {
        context: {
          ...ctx.context,
          tenantConfig,
        },
      };
    }),
  },
});

// A helper function to simulate fetching tenant configuration.
// Replace this with your actual implementation.
async function getTenantConfig(tenantId: string) {
  // Example: Return a dummy connection string based on the tenantId.
  return {
    connectionString: `postgres://user:pass@host:port/db_${tenantId}`,
  };
}

import { betterAuth } from "better-auth";
import { createAuthMiddleware, APIError } from "better-auth/api";

// Define your auth instance with a before hook
export const auth = betterAuth({
  hooks: {
    before: createAuthMiddleware(async (ctx) => {
      // Extract the tenant header from the request headers (e.g., "X-Tenant-ID")
      const tenantId = ctx.headers.get("X-Tenant-ID");
      if (!tenantId) {
        throw new APIError("BAD_REQUEST", { message: "Missing tenant header" });
      }

      // Retrieve tenant-specific configuration (for example, a connection string)
      // This is a placeholder function; in a real app, replace it with your own logic.
      const tenantConfig = await getTenantConfig(tenantId);

      // Inject the tenant configuration into the context.
      // Now the adapter and other parts of Better Auth can use ctx.context.tenantConfig.
      return {
        context: {
          ...ctx.context,
          tenantConfig,
        },
      };
    }),
  },
});

// A helper function to simulate fetching tenant configuration.
// Replace this with your actual implementation.
async function getTenantConfig(tenantId: string) {
  // Example: Return a dummy connection string based on the tenantId.
  return {
    connectionString: `postgres://user:pass@host:port/db_${tenantId}`,
  };
}