feat(build): Add NeonDB branch resolution for Vercel preview environments

docs/config/extensions/syncEnvVars.mdx

@@ -80,6 +80,14 @@ The `syncVercelEnvVars` build extension syncs environment variables from your Ve
   the project with the environment variables you want to sync.
 </Note>
 
+<Note>
+  When running the build from a Vercel build environment (e.g., during a Vercel deployment), the
+  environment variable values will be read from `process.env` instead of fetching them from the
+  Vercel API. This is determined by checking if the `VERCEL` environment variable is present. The
+  API is still used to determine which environment variables are configured for your project, but
+  the actual values come from the local environment.
+</Note>
+
 ```ts
 import { defineConfig } from "@trigger.dev/sdk";
 import { syncVercelEnvVars } from "@trigger.dev/build/extensions/core";
@@ -114,3 +122,71 @@ export default defineConfig({
   },
 });
 ```
+
+### syncNeonEnvVars
+
+The `syncNeonEnvVars` build extension syncs environment variables from your Neon database project to Trigger.dev. It automatically detects branches and builds the appropriate database connection strings for your environment.
+
+<Note>
+  You need to set the `NEON_ACCESS_TOKEN` and `NEON_PROJECT_ID` environment variables, or pass them
+  as arguments to the `syncNeonEnvVars` build extension. You can generate a `NEON_ACCESS_TOKEN` in
+  your Neon [dashboard](https://console.neon.tech/app/settings/api-keys).
+</Note>
+
+<Note>
+  When running the build from a Vercel environment (determined by checking if the `VERCEL`
+  environment variable is present), this extension is skipped entirely. This is because Neon's
+  Vercel integration already handles environment variable synchronization in Vercel environments.
+</Note>
+
+<Note>
+  This extension is skipped for `prod` environments. It is designed to sync branch-specific
+  database connections for preview/staging/dev environments.
+</Note>
+
+```ts
+import { defineConfig } from "@trigger.dev/sdk";
+import { syncNeonEnvVars } from "@trigger.dev/build/extensions/core";
+
+export default defineConfig({
+  project: "<project ref>",
+  // Your other config settings...
+  build: {
+    // This will automatically use the NEON_ACCESS_TOKEN and NEON_PROJECT_ID environment variables
+    extensions: [syncNeonEnvVars()],
+  },
+});
+```
+
+Or you can pass in the token and project ID as arguments:
+
+```ts
+import { defineConfig } from "@trigger.dev/sdk";
+import { syncNeonEnvVars } from "@trigger.dev/build/extensions/core";
+
+export default defineConfig({
+  project: "<project ref>",
+  // Your other config settings...
+  build: {
+    extensions: [
+      syncNeonEnvVars({
+        projectId: "your-neon-project-id",
+        neonAccessToken: "your-neon-access-token",
+        branch: "your-branch-name", // optional, defaults to ctx.branch
+        databaseName: "your-database-name", // optional, defaults to the first database
+        roleName: "your-role-name", // optional, defaults to the database owner
+        envVarPrefix: "MY_PREFIX_", // optional, prefix for all synced env vars
+      }),
+    ],
+  },
+});
+```
+
+The extension syncs the following environment variables (with optional prefix):
+
+- `DATABASE_URL` - Pooled connection string
+- `DATABASE_URL_UNPOOLED` - Direct connection string
+- `POSTGRES_URL`, `POSTGRES_URL_NO_SSL`, `POSTGRES_URL_NON_POOLING`
+- `POSTGRES_PRISMA_URL` - Connection string optimized for Prisma
+- `POSTGRES_HOST`, `POSTGRES_USER`, `POSTGRES_PASSWORD`, `POSTGRES_DATABASE`
+- `PGHOST`, `PGHOST_UNPOOLED`, `PGUSER`, `PGPASSWORD`, `PGDATABASE`

docs/guides/examples/vercel-sync-env-vars.mdx

@@ -19,6 +19,14 @@ To sync environment variables, you just need to add our build extension to your
   the project with the environment variables you want to sync.
 </Note>
 
+<Note>
+  When running the build from a Vercel build environment (e.g., during a Vercel deployment), the
+  environment variable values will be read from `process.env` instead of fetching them from the
+  Vercel API. This is determined by checking if the `VERCEL` environment variable is present. The
+  API is still used to determine which environment variables are configured for your project, but
+  the actual values come from the local environment.
+</Note>
+
 ```ts trigger.config.ts
 import { defineConfig } from "@trigger.dev/sdk";
 import { syncVercelEnvVars } from "@trigger.dev/build/extensions/core";

packages/build/src/extensions/core.ts

@@ -3,4 +3,5 @@ export * from "./core/additionalPackages.js";
 export * from "./core/syncEnvVars.js";
 export * from "./core/aptGet.js";
 export * from "./core/ffmpeg.js";
+export * from "./core/neonSyncEnvVars.js";
 export * from "./core/vercelSyncEnvVars.js";

packages/build/src/extensions/core/neonSyncEnvVars.ts

@@ -0,0 +1,289 @@
+import { BuildExtension } from "@trigger.dev/core/v3/build";
+import { syncEnvVars } from "../core.js";
+
+type EnvVar = { name: string; value: string; isParentEnv?: boolean };
+
+type NeonBranch = {
+  id: string;
+  name: string;
+};
+
+type NeonEndpoint = {
+  id: string;
+  host: string;
+  type: string;
+};
+
+type NeonDatabase = {
+  id: number;
+  name: string;
+  owner_name: string;
+};
+
+type NeonRole = {
+  name: string;
+  password?: string;
+};
+
+// List of Neon DB related environment variables to sync
+export const NEON_ENV_VARS = [
+  "PGUSER",
+  "POSTGRES_URL_NO_SSL",
+  "POSTGRES_HOST",
+  "POSTGRES_URL",
+  "POSTGRES_PRISMA_URL",
+  "DATABASE_URL_UNPOOLED",
+  "POSTGRES_URL_NON_POOLING",
+  "PGHOST",
+  "POSTGRES_USER",
+  "DATABASE_URL",
+  "POSTGRES_PASSWORD",
+  "POSTGRES_DATABASE",
+  "PGPASSWORD",
+  "PGDATABASE",
+  "PGHOST_UNPOOLED",
+];
+
+function buildNeonEnvVarMappings(options: {
+  user: string;
+  password: string;
+  database: string;
+  host: string;
+  poolerHost: string;
+}): Record<string, string> {
+  const { user, password, database, host, poolerHost } = options;
+
+  return {
+    PGUSER: user,
+    PGPASSWORD: password,
+    PGDATABASE: database,
+    PGHOST: poolerHost,
+    PGHOST_UNPOOLED: host,
+    POSTGRES_USER: user,
+    POSTGRES_PASSWORD: password,
+    POSTGRES_DATABASE: database,
+    POSTGRES_HOST: poolerHost,
+    DATABASE_URL: `postgresql://${encodeURIComponent(user)}:${encodeURIComponent(password)}@${poolerHost}/${database}?sslmode=require`,
+    DATABASE_URL_UNPOOLED: `postgresql://${encodeURIComponent(user)}:${encodeURIComponent(password)}@${host}/${database}?sslmode=require`,
+    POSTGRES_URL: `postgresql://${encodeURIComponent(user)}:${encodeURIComponent(password)}@${poolerHost}/${database}?sslmode=require`,
+    POSTGRES_URL_NO_SSL: `postgresql://${encodeURIComponent(user)}:${encodeURIComponent(password)}@${poolerHost}/${database}`,
+    POSTGRES_URL_NON_POOLING: `postgresql://${encodeURIComponent(user)}:${encodeURIComponent(password)}@${host}/${database}?sslmode=require`,
+    POSTGRES_PRISMA_URL: `postgresql://${encodeURIComponent(user)}:${encodeURIComponent(password)}@${poolerHost}/${database}?sslmode=require&pgbouncer=true&connect_timeout=15`,
+  };
+}
+
+export function syncNeonEnvVars(options?: {
+  projectId?: string;
+  neonAccessToken?: string;
+  branch?: string;
+  databaseName?: string;
+  roleName?: string;
+  envVarPrefix?: string;
+}): BuildExtension {
+  const sync = syncEnvVars(async (ctx) => {
+    const projectId =
+      options?.projectId ?? process.env.NEON_PROJECT_ID ?? ctx.env.NEON_PROJECT_ID;
+    const neonAccessToken =
+      options?.neonAccessToken ?? process.env.NEON_ACCESS_TOKEN ?? ctx.env.NEON_ACCESS_TOKEN;
+    const branch = options?.branch ?? ctx.branch;
+    const envVarPrefix = options?.envVarPrefix ?? "";
+    const outputEnvVars = NEON_ENV_VARS;
+
+    // Skip the whole process for Vercel environments
+    if (ctx.env.VERCEL) {
+      return [];
+    }
+
+    if (!projectId) {
+      throw new Error(
+        "syncNeonEnvVars: you did not pass in a projectId or set the NEON_PROJECT_ID env var."
+      );
+    }
+
+    if (!neonAccessToken) {
+      throw new Error(
+        "syncNeonEnvVars: you did not pass in an neonAccessToken or set the NEON_ACCESS_TOKEN env var."
+      );
+    }
+
+    // Skip branch-specific logic for production environment
+    if (ctx.environment === "prod") {
+      return [];
+    }
+
+    if (!branch) {
+      throw new Error(
+        "syncNeonEnvVars: you did not pass in a branch and no branch was detected from context."
+      );
+    }
+
+    const environmentMap = {
+      prod: "production",
+      staging: "preview",
+      dev: "development",
+      preview: "preview",
+    } as const;
+
+    const environment = environmentMap[ctx.environment as keyof typeof environmentMap];
+
+    if (!environment) {
+      throw new Error(
+        `Invalid environment '${ctx.environment}'. Expected 'prod', 'staging', 'dev', or 'preview'.`
+      );
+    }
+
+    try {
+      // Step 1: Search for the branch in Neon
+      const branchSearchParams = new URLSearchParams({ search: branch });
+      const branchesUrl = `https://console.neon.tech/api/v2/projects/${projectId}/branches?${branchSearchParams}`;
+      const branchesResponse = await fetch(branchesUrl, {
+        headers: {
+          Authorization: `Bearer ${neonAccessToken}`,
+        },
+      });
+
+      if (!branchesResponse.ok) {
+        throw new Error(`Failed to fetch Neon branches: ${branchesResponse.status}`);
+      }
+
+      const branchesData = await branchesResponse.json();
+      const branches: NeonBranch[] = branchesData.branches || [];
+
+      if (branches.length === 0) {
+        // No matching branch found
+        return [];
+      }
+
+      // Neon branch names are prefixed with environment (e.g., "preview/branch-name")
+      const expectedBranchName = `${environment}/${branch}`;
+      const matchingBranch = branches.find(
+        (b) => b.name === expectedBranchName || b.name === branch
+      );
+
+      if (!matchingBranch) {
+        // No exact match found
+        return [];
+      }
+
+      const neonBranchId = matchingBranch.id;
+
+      // Step 2: Get endpoints for the branch
+      const endpointsUrl = `https://console.neon.tech/api/v2/projects/${projectId}/branches/${neonBranchId}/endpoints`;
+      const endpointsResponse = await fetch(endpointsUrl, {
+        headers: {
+          Authorization: `Bearer ${neonAccessToken}`,
+        },
+      });
+
+      if (!endpointsResponse.ok) {
+        throw new Error(`Failed to fetch Neon branch endpoints: ${endpointsResponse.status}`);
+      }
+
+      const endpointsData = await endpointsResponse.json();
+      const endpoints: NeonEndpoint[] = endpointsData.endpoints || [];
+
+      if (endpoints.length === 0) {
+        return [];
+      }
+
+      // Find an endpoint with type containing 'write', or take the first one
+      const writeEndpoint = endpoints.find((ep) => ep.type.includes("write"));
+      const endpoint = writeEndpoint || endpoints[0];
+
+      if (!endpoint) {
+        return [];
+      }
+
+      // Step 3: Get databases for the branch
+      const databasesUrl = `https://console.neon.tech/api/v2/projects/${projectId}/branches/${neonBranchId}/databases`;
+      const databasesResponse = await fetch(databasesUrl, {
+        headers: {
+          Authorization: `Bearer ${neonAccessToken}`,
+        },
+      });
+
+      if (!databasesResponse.ok) {
+        throw new Error(`Failed to fetch Neon branch databases: ${databasesResponse.status}`);
+      }
+
+      const databasesData = await databasesResponse.json();
+      const databases: NeonDatabase[] = databasesData.databases || [];
+
+      if (databases.length === 0) {
+        return [];
+      }
+
+      // Find the specified database or use the first one
+      const targetDatabase = options?.databaseName
+        ? databases.find((db) => db.name === options.databaseName)
+        : databases[0];
+
+      if (!targetDatabase) {
+        throw new Error(
+          `syncNeonEnvVars: Database '${options?.databaseName}' not found in branch.`
+        );
+      }
+
+      // Step 4: Get the role (user) and password
+      const targetRoleName = options?.roleName ?? targetDatabase.owner_name;
+      const rolePasswordUrl = `https://console.neon.tech/api/v2/projects/${projectId}/branches/${neonBranchId}/roles/${targetRoleName}/reveal_password`;
+      const rolePasswordResponse = await fetch(rolePasswordUrl, {
+        headers: {
+          Authorization: `Bearer ${neonAccessToken}`,
+        },
+      });
+
+      if (!rolePasswordResponse.ok) {
+        throw new Error(
+          `Failed to fetch Neon role password: ${rolePasswordResponse.status}. Make sure the role '${targetRoleName}' exists and has a password.`
+        );
+      }
+
+      const rolePasswordData: NeonRole = await rolePasswordResponse.json();
+      const password = rolePasswordData.password;
+
+      if (!password) {
+        throw new Error(
+          `syncNeonEnvVars: No password found for role '${targetRoleName}'. The role may not have a password set.`
+        );
+      }
+
+      // Step 5: Build new environment variables based on the endpoint host
+      const newHost = endpoint.host;
+      const poolerHost = newHost.replace(/^([^.]+)\./, "$1-pooler.");
+
+      const envVarMappings = buildNeonEnvVarMappings({
+        user: targetRoleName,
+        password,
+        database: targetDatabase.name,
+        host: newHost,
+        poolerHost,
+      });
+
+      // Build output env vars
+      const newEnvVars: EnvVar[] = [];
+
+      for (const neonEnvVar of outputEnvVars) {
+        const prefixedKey = `${envVarPrefix}${neonEnvVar}`;
+        if (envVarMappings[neonEnvVar]) {
+          newEnvVars.push({
+            name: prefixedKey,
+            value: envVarMappings[neonEnvVar],
+          });
+        }
+      }
+
+      return newEnvVars;
+    } catch (error) {
+      console.error("Error fetching Neon branch environment variables:", error);
+      throw error;
+    }
+  });
+
+  return {
+    name: "SyncNeonEnvVarsExtension",
+    async onBuildComplete(context, manifest) {
+      await sync.onBuildComplete?.(context, manifest);
+    },
+  };
+}