| 1 | --- |
| 2 | title: Aurora Data API |
| 3 | description: Deploy a Better Auth Lambda with Aurora PostgreSQL over HTTPS and automatic IAM bindings. |
| 4 | --- |
| 5 | |
| 6 | This example creates Aurora PostgreSQL and serves Better Auth through a Lambda Function URL. Aurora needs a VPC, but Lambda reaches the Data API over HTTPS without joining that VPC. |
| 7 | |
| 8 | ## Install |
| 9 | |
| 10 | ```sh |
| 11 | bun add @alchemy.run/better-auth better-auth@^1.7.5 kysely @distilled.cloud/aws |
| 12 | ``` |
| 13 | |
| 14 | Configure AWS through an [Alchemy profile](/environments/profiles) in a region supporting Aurora PostgreSQL's Data API. No `pg` driver or TCP connection pool is required. |
| 15 | |
| 16 | ## Define the database and network |
| 17 | |
| 18 | ```typescript title="src/database.ts" |
| 19 | import * as AWS from "alchemy/AWS"; |
| 20 | import * as Effect from "effect/Effect"; |
| 21 | |
| 22 | export const AuthDb = Effect.gen(function* () { |
| 23 | const network = yield* AWS.EC2.Network("AuthNetwork", { |
| 24 | cidrBlock: "10.42.0.0/16", |
| 25 | availabilityZones: 2, |
| 26 | }); |
| 27 | const securityGroup = yield* AWS.EC2.SecurityGroup("AuthSecurityGroup", { |
| 28 | vpcId: network.vpcId, |
| 29 | description: "Aurora auth database", |
| 30 | }); |
| 31 | return yield* AWS.RDS.Aurora("AuthDb", { |
| 32 | databaseName: "auth", |
| 33 | subnetIds: network.privateSubnetIds, |
| 34 | securityGroupIds: [securityGroup.groupId], |
| 35 | dataApi: true, |
| 36 | }); |
| 37 | }); |
| 38 | ``` |
| 39 | |
| 40 | The Aurora composite creates the cluster, writer, and database-credentials secret. The security group needs no inbound Postgres rule for Data API access. |
| 41 | |
| 42 | ## Define the auth Lambda |
| 43 | |
| 44 | ```typescript title="src/function.ts" |
| 45 | import { BetterAuth } from "@alchemy.run/better-auth"; |
| 46 | import { AuroraDataApi } from "@alchemy.run/better-auth/AuroraDataApi"; |
| 47 | import * as AWS from "alchemy/AWS"; |
| 48 | import * as Duration from "effect/Duration"; |
| 49 | import * as Effect from "effect/Effect"; |
| 50 | import { AuthDb } from "./database.ts"; |
| 51 | |
| 52 | export default class AuthApi extends AWS.Lambda.Function<AuthApi>()( |
| 53 | "AuthApi", |
| 54 | { |
| 55 | main: import.meta.url, |
| 56 | functionUrl: true, |
| 57 | memorySize: 512, |
| 58 | timeout: Duration.seconds(30), |
| 59 | }, |
| 60 | Effect.gen(function* () { |
| 61 | const auth = yield* BetterAuth({ |
| 62 | basePath: "/api/auth", |
| 63 | emailAndPassword: { enabled: true }, |
| 64 | }); |
| 65 | return { fetch: auth.fetch }; |
| 66 | }).pipe(Effect.provide(AuroraDataApi(AuthDb, { database: "auth" }))), |
| 67 | ) {} |
| 68 | ``` |
| 69 | |
| 70 | The database layer binds cluster and secret identifiers and grants the function Data API and Secrets Manager permissions. The public Function URL serves auth endpoints under `/api/auth`. |
| 71 | |
| 72 | ## Define the stack |
| 73 | |
| 74 | ```typescript title="alchemy.run.ts" |
| 75 | import * as Alchemy from "alchemy"; |
| 76 | import * as AWS from "alchemy/AWS"; |
| 77 | import * as Effect from "effect/Effect"; |
| 78 | import AuthApi from "./src/function.ts"; |
| 79 | |
| 80 | export default Alchemy.Stack( |
| 81 | "BetterAuthAurora", |
| 82 | { |
| 83 | providers: AWS.providers(), |
| 84 | state: Alchemy.localState(), |
| 85 | }, |
| 86 | Effect.gen(function* () { |
| 87 | const api = yield* AuthApi; |
| 88 | return { url: api.functionUrl }; |
| 89 | }), |
| 90 | ); |
| 91 | ``` |
| 92 | |
| 93 | The auth signing secret is generated and bound automatically, separately from Aurora's database-credentials secret. Preserve and protect local `.alchemy` state across deployments. |
| 94 | |
| 95 | ## Deploy and migrate |
| 96 | |
| 97 | ```sh |
| 98 | bunx alchemy deploy |
| 99 | ``` |
| 100 | |
| 101 | Automatic migrations wait for the writer and use the Data API with deploy-time AWS credentials. Those credentials need database and secret access too; the function's IAM bindings do not grant permissions to the deployer. |
| 102 | |
| 103 | Set `AUTH_ORIGIN` to the printed Function URL and verify the endpoint: |
| 104 | |
| 105 | ```sh |
| 106 | curl -i "$AUTH_ORIGIN/api/auth/get-session" |
| 107 | ``` |
| 108 | |
| 109 | ## Cluster and migration options |
| 110 | |
| 111 | For a bare `AWS.RDS.DBCluster` resource, provide an `AWS.SecretsManager.Secret` resource through the layer's `secret` option. Passing the Aurora composite, as above, also supplies the writer dependency needed to order migrations. |
| 112 | |
| 113 | The layer retries transient errors while a Serverless v2 cluster resumes, with bounded retries at deployment and runtime. SQL runs within each invocation without retaining a TCP connection across invocations. |
| 114 | |
| 115 | The layer's `migrate: false` option disables automatic migration support; Better Auth's own `migrate: false` also opts out of its migration Action. Automatic migrations are additive and do not move records between databases. |
| 116 | |
| 117 | See [configuration](/better-auth/guides/configuration), [migrations](/better-auth/guides/migrations), the [upgrade guide](/better-auth/upgrades/from-1-6-to-1-7), and the [`AuroraDataApi` reference](/providers/betterauth/auroradataapi). |