diff --git a/backend/src/helpers/auth.ts b/backend/src/helpers/auth.ts
index be10dbbfa..58f8c0e15 100644
--- a/backend/src/helpers/auth.ts
+++ b/backend/src/helpers/auth.ts
@@ -7,6 +7,7 @@ import {
 	ITokenVersion,
 	IUser,
 	ServiceTokenData,
+	ServiceTokenDataV3,
 	TokenVersion,
 	User,
 } from "../models";
@@ -29,6 +30,7 @@ import {
 } from "../variables";
 import {
 	ServiceTokenAuthData,
+	ServiceTokenV3AuthData,
 	UserAuthData
 } from "../interfaces/middleware";
 
@@ -47,6 +49,9 @@ export const validateAuthMode = ({
 	headers: { [key: string]: string | string[] | undefined },
 	acceptedAuthModes: AuthMode[]
 }) => {
+	
+	// TODO: update this to accept service token v3
+	
 	const apiKey = headers["x-api-key"];
 	const authHeader = headers["authorization"];
 
@@ -76,6 +81,9 @@ export const validateAuthMode = ({
 			case "st":
 				authMode = AuthMode.SERVICE_TOKEN;
 				break;
+			case "proj_token":
+				authMode = AuthMode.SERVICE_TOKEN_V3;
+				break;
 			default:
 				authMode = AuthMode.JWT;
 		}
@@ -211,8 +219,55 @@ export const getAuthSTDPayload = async ({
 		userAgent: req.headers["user-agent"] ?? "",
 		userAgentType: getUserAgentType(req.headers["user-agent"])
 	}
+}
 
-	// return serviceTokenDataToReturn;
+/**
+ * Return service token data V3 payload corresponding to service token [authTokenValue]
+ * @param {Object} obj
+ * @param {String} obj.authTokenValue - service token value
+ * @returns {ServiceTokenData} serviceTokenData - service token data
+ */
+ export const getAuthSTDV3Payload = async ({
+	req,
+	authTokenValue,
+}: {
+	req: Request,
+	authTokenValue: string;
+}): Promise<ServiceTokenV3AuthData> => {
+	const decodedToken = <jwt.UserIDJwtPayload>(
+		jwt.verify(authTokenValue, "hello") // TODO: change this
+	);
+
+	// perhaps turn this one into a find one and update call?
+	const serviceTokenData = await ServiceTokenDataV3.findOne({
+		_id: new Types.ObjectId(decodedToken.serviceTokenDataId),
+	});
+
+	if (!serviceTokenData) {
+		throw UnauthorizedRequestError({ 
+			message: "Failed to authenticate" // standardize auth error messages
+		});
+	} else if (serviceTokenData?.expiresAt && new Date(serviceTokenData.expiresAt) < new Date()) {
+		// case: service token expired
+		await ServiceTokenDataV3.findByIdAndDelete(serviceTokenData._id);
+		throw UnauthorizedRequestError({
+			message: "Failed to authenticate",
+		});
+	}
+	
+	return {
+		actor: {
+			type: ActorType.SERVICE, // should this be servicev3 bc the shape of it is different?
+			metadata: {
+				serviceId: serviceTokenData._id.toString(),
+				name: serviceTokenData.name
+			}
+		},
+		authPayload: serviceTokenData,
+		ipAddress: req.realIP,
+		userAgent: req.headers["user-agent"] ?? "",
+		userAgentType: getUserAgentType(req.headers["user-agent"])
+	}
 }
 
 /**
diff --git a/backend/src/interfaces/middleware/index.ts b/backend/src/interfaces/middleware/index.ts
index e8dd1b91b..f873eff26 100644
--- a/backend/src/interfaces/middleware/index.ts
+++ b/backend/src/interfaces/middleware/index.ts
@@ -1,6 +1,7 @@
 import { Types } from "mongoose";
 import {
     IServiceTokenData,
+    IServiceTokenDataV3,
     IUser,
 } from "../../models";
 import { 
@@ -21,6 +22,11 @@ export interface UserAuthData extends BaseAuthData {
     authPayload: IUser;
 }
 
+export interface ServiceTokenV3AuthData extends BaseAuthData {
+    actor: ServiceActor;
+    authPayload: IServiceTokenDataV3;
+}
+
 export interface ServiceTokenAuthData extends BaseAuthData {
     actor: ServiceActor;
     authPayload: IServiceTokenData;
@@ -28,4 +34,5 @@ export interface ServiceTokenAuthData extends BaseAuthData {
 
 export type AuthData =
     | UserAuthData
+    | ServiceTokenV3AuthData
     | ServiceTokenAuthData;
\ No newline at end of file
diff --git a/backend/src/middleware/requireAuth.ts b/backend/src/middleware/requireAuth.ts
index e256f6665..aa74b0dc7 100644
--- a/backend/src/middleware/requireAuth.ts
+++ b/backend/src/middleware/requireAuth.ts
@@ -3,6 +3,7 @@ import { NextFunction, Request, Response } from "express";
 import {
 	getAuthAPIKeyPayload,
 	getAuthSTDPayload,
+	getAuthSTDV3Payload,
 	getAuthUserPayload,
 	validateAuthMode,
 } from "../helpers/auth";
@@ -49,6 +50,12 @@ const requireAuth = ({
 				});
 				req.serviceTokenData = authData.authPayload;
 				break;
+			case AuthMode.SERVICE_TOKEN_V3:
+				authData = await getAuthSTDV3Payload({
+					req,
+					authTokenValue
+				});
+				break;
 			case AuthMode.API_KEY:
 				authData = await getAuthAPIKeyPayload({
 					req,
@@ -61,9 +68,7 @@ const requireAuth = ({
 					req,
 					authTokenValue
 				});
-				// authPayload = authUserPayload.user;
 				req.user = authData.authPayload;
-				// req.tokenVersionId = authUserPayload.tokenVersionId; // TODO
 				break;
 		}
 		
diff --git a/backend/src/models/serviceTokenDataV3.ts b/backend/src/models/serviceTokenDataV3.ts
index 049c2a33c..e30420e04 100644
--- a/backend/src/models/serviceTokenDataV3.ts
+++ b/backend/src/models/serviceTokenDataV3.ts
@@ -17,7 +17,8 @@ export interface IServiceTokenDataV3 extends Document {
     workspace: Types.ObjectId;
     publicKey: string;
     isActive: boolean;
-    lastUsed: Date;
+    lastUsed?: Date;
+    expiresAt?: Date;
     scopes: Array<Scope>;
 }
 
diff --git a/backend/src/validation/integrationAuth.ts b/backend/src/validation/integrationAuth.ts
index cf3f936a9..af73257c6 100644
--- a/backend/src/validation/integrationAuth.ts
+++ b/backend/src/validation/integrationAuth.ts
@@ -154,7 +154,7 @@ export const DeleteIntegrationAuthV1 = z.object({
 
 export const GetIntegrationAuthTeamCityBuildConfigsV1 = z.object({
   params:z.object({
-    appId:z.string().trim(),
+    appId:z.string().trim().optional(),
     integrationAuthId:z.string().trim()
   })
 })
diff --git a/backend/src/variables/authentication.ts b/backend/src/variables/authentication.ts
index be2f35c81..1376c977e 100644
--- a/backend/src/variables/authentication.ts
+++ b/backend/src/variables/authentication.ts
@@ -1,6 +1,7 @@
 export enum AuthMode {
     JWT = "jwt",
     SERVICE_TOKEN = "serviceToken",
+    SERVICE_TOKEN_V3 = "serviceTokenV3",
     API_KEY = "apiKey"
 }