diff --git a/backend/src/@types/fastify.d.ts b/backend/src/@types/fastify.d.ts
index a2bc332f8..be484b5fd 100644
--- a/backend/src/@types/fastify.d.ts
+++ b/backend/src/@types/fastify.d.ts
@@ -105,6 +105,7 @@ import { TPkiCollectionServiceFactory } from "@app/services/pki-collection/pki-c
 import { TPkiSubscriberServiceFactory } from "@app/services/pki-subscriber/pki-subscriber-service";
 import { TPkiSyncServiceFactory } from "@app/services/pki-sync/pki-sync-service";
 import { TPkiTemplatesServiceFactory } from "@app/services/pki-templates/pki-templates-service";
+import { TPkiAcmeServiceFactory } from "@app/ee/services/pki-acme/pki-acme-types";
 import { TProjectServiceFactory } from "@app/services/project/project-service";
 import { TProjectBotServiceFactory } from "@app/services/project-bot/project-bot-service";
 import { TProjectEnvServiceFactory } from "@app/services/project-env/project-env-service";
@@ -294,6 +295,7 @@ declare module "fastify" {
       certificateAuthority: TCertificateAuthorityServiceFactory;
       certificateAuthorityCrl: TCertificateAuthorityCrlServiceFactory;
       certificateEst: TCertificateEstServiceFactory;
+      pkiAcme: TPkiAcmeServiceFactory;
       certificateEstV3: TCertificateEstV3ServiceFactory;
       pkiCollection: TPkiCollectionServiceFactory;
       pkiSubscriber: TPkiSubscriberServiceFactory;
diff --git a/backend/src/ee/routes/v1/pki-acme-router.ts b/backend/src/ee/routes/v1/pki-acme-router.ts
index b308c8d58..f9342a825 100644
--- a/backend/src/ee/routes/v1/pki-acme-router.ts
+++ b/backend/src/ee/routes/v1/pki-acme-router.ts
@@ -3,6 +3,28 @@ import { z } from "zod";
 
 import { ApiDocsTags } from "@app/lib/api-docs";
 import { readLimit, writeLimit } from "@app/server/config/rateLimiter";
+import {
+  CreateAcmeAccountResponseSchema,
+  CreateAcmeAccountSchema,
+  CreateAcmeOrderResponseSchema,
+  CreateAcmeOrderSchema,
+  DeactivateAcmeAccountResponseSchema,
+  DeactivateAcmeAccountSchema,
+  DownloadAcmeCertificateSchema,
+  FinalizeAcmeOrderResponseSchema,
+  FinalizeAcmeOrderSchema,
+  GetAcmeAuthorizationResponseSchema,
+  GetAcmeAuthorizationSchema,
+  GetAcmeDirectoryResponseSchema,
+  GetAcmeDirectorySchema,
+  GetAcmeNewNonceSchema,
+  GetAcmeOrderResponseSchema,
+  GetAcmeOrderSchema,
+  ListAcmeOrdersResponseSchema,
+  ListAcmeOrdersSchema,
+  RespondToAcmeChallengeResponseSchema,
+  RespondToAcmeChallengeSchema
+} from "@app/ee/services/pki-acme/pki-acme-schemas";
 
 export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
   // GET /api/v1/pki/acme/profiles/<profile_id>/directory
@@ -17,27 +39,14 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
       hide: false,
       tags: [ApiDocsTags.PkiAcme],
       description: "ACME Directory - provides URLs for the client to make API calls to",
-      params: z.object({
-        profileId: z.string().uuid()
-      }),
+      ...GetAcmeDirectorySchema.shape,
       response: {
-        200: z.object({
-          newNonce: z.string(),
-          newAccount: z.string(),
-          newOrder: z.string(),
-          revokeCert: z.string()
-        })
+        200: GetAcmeDirectoryResponseSchema
       }
     },
     handler: async (req) => {
-      // FIXME: Implement ACME directory endpoint
-      // This endpoint should return the base URLs for ACME operations
-      return {
-        newNonce: `/api/v1/pki/acme/profiles/${req.params.profileId}/new-nonce`,
-        newAccount: `/api/v1/pki/acme/profiles/${req.params.profileId}/new-account`,
-        newOrder: `/api/v1/pki/acme/profiles/${req.params.profileId}/new-order`,
-        revokeCert: `/api/v1/pki/acme/profiles/${req.params.profileId}/revoke-cert`
-      };
+      const directory = await server.services.pkiAcme.getAcmeDirectory(req.params.profileId);
+      return directory;
     }
   });
 
@@ -54,17 +63,13 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
       hide: false,
       tags: [ApiDocsTags.PkiAcme],
       description: "ACME New Nonce - generate a new nonce and return in Replay-Nonce header",
-      params: z.object({
-        profileId: z.string().uuid()
-      }),
+      ...GetAcmeNewNonceSchema.shape,
       response: {
         200: z.object({})
       }
     },
     handler: async (req, res) => {
-      // FIXME: Implement ACME new nonce generation
-      // Generate a new nonce, store it, and return it in the Replay-Nonce header
-      const nonce = "FIXME-generate-nonce";
+      const nonce = await server.services.pkiAcme.getAcmeNewNonce(req.params.profileId);
       res.header("Replay-Nonce", nonce);
       return {};
     }
@@ -82,40 +87,15 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
       hide: false,
       tags: [ApiDocsTags.PkiAcme],
       description: "ACME New Account - register a new account or find existing one",
-      params: z.object({
-        profileId: z.string().uuid()
-      }),
-      body: z.object({
-        contact: z.array(z.string()).optional(),
-        termsOfServiceAgreed: z.boolean().optional(),
-        onlyReturnExisting: z.boolean().optional(),
-        externalAccountBinding: z
-          .object({
-            protected: z.string(),
-            payload: z.string(),
-            signature: z.string()
-          })
-          .optional()
-      }),
+      ...CreateAcmeAccountSchema.shape,
       response: {
-        201: z.object({
-          status: z.string(),
-          contact: z.array(z.string()).optional(),
-          orders: z.string().optional(),
-          accountUrl: z.string()
-        })
+        201: CreateAcmeAccountResponseSchema
       }
     },
-    handler: async (req) => {
-      // FIXME: Implement ACME new account registration
-      // Use EAB authentication to find corresponding Infisical machine identity
-      // Check permissions and return account information
-      return {
-        status: "valid",
-        accountUrl: `/api/v1/pki/acme/profiles/${req.params.profileId}/accounts/FIXME-account-id`,
-        contact: req.body.contact,
-        orders: `/api/v1/pki/acme/profiles/${req.params.profileId}/accounts/FIXME-account-id/orders`
-      };
+    handler: async (req, res) => {
+      const account = await server.services.pkiAcme.createAcmeAccount(req.params.profileId, req.body);
+      res.code(201);
+      return account;
     }
   });
 
@@ -131,47 +111,15 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
       hide: false,
       tags: [ApiDocsTags.PkiAcme],
       description: "ACME New Order - apply for a new certificate",
-      params: z.object({
-        profileId: z.string().uuid()
-      }),
-      body: z.object({
-        identifiers: z.array(
-          z.object({
-            type: z.string(),
-            value: z.string()
-          })
-        ),
-        notBefore: z.string().optional(),
-        notAfter: z.string().optional()
-      }),
+      ...CreateAcmeOrderSchema.shape,
       response: {
-        201: z.object({
-          status: z.string(),
-          expires: z.string(),
-          identifiers: z.array(
-            z.object({
-              type: z.string(),
-              value: z.string()
-            })
-          ),
-          authorizations: z.array(z.string()),
-          finalize: z.string(),
-          certificate: z.string().optional()
-        })
+        201: CreateAcmeOrderResponseSchema
       }
     },
-    handler: async (req) => {
-      // FIXME: Implement ACME new order creation
-      const orderId = "FIXME-order-id";
-      return {
-        status: "pending",
-        expires: new Date(Date.now() + 24 * 60 * 60 * 1000).toISOString(),
-        identifiers: req.body.identifiers,
-        authorizations: req.body.identifiers.map(
-          (id) => `/api/v1/pki/acme/profiles/${req.params.profileId}/authorizations/FIXME-authz-${id.value}`
-        ),
-        finalize: `/api/v1/pki/acme/profiles/${req.params.profileId}/orders/${orderId}/finalize`
-      };
+    handler: async (req, res) => {
+      const order = await server.services.pkiAcme.createAcmeOrder(req.params.profileId, req.body);
+      res.code(201);
+      return order;
     }
   });
 
@@ -187,24 +135,14 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
       hide: false,
       tags: [ApiDocsTags.PkiAcme],
       description: "ACME Account Deactivation",
-      params: z.object({
-        profileId: z.string().uuid(),
-        accountId: z.string()
-      }),
-      body: z.object({
-        status: z.literal("deactivated")
-      }),
+      ...DeactivateAcmeAccountSchema.shape,
       response: {
-        200: z.object({
-          status: z.string()
-        })
+        200: DeactivateAcmeAccountResponseSchema
       }
     },
     handler: async (req) => {
-      // FIXME: Implement ACME account deactivation
-      return {
-        status: "deactivated"
-      };
+      const result = await server.services.pkiAcme.deactivateAcmeAccount(req.params.profileId, req.params.accountId);
+      return result;
     }
   });
 
@@ -220,21 +158,14 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
       hide: false,
       tags: [ApiDocsTags.PkiAcme],
       description: "ACME List Orders - get existing orders from current account",
-      params: z.object({
-        profileId: z.string().uuid(),
-        accountId: z.string()
-      }),
+      ...ListAcmeOrdersSchema.shape,
       response: {
-        200: z.object({
-          orders: z.array(z.string())
-        })
+        200: ListAcmeOrdersResponseSchema
       }
     },
     handler: async (req) => {
-      // FIXME: Implement ACME list orders
-      return {
-        orders: []
-      };
+      const orders = await server.services.pkiAcme.listAcmeOrders(req.params.profileId, req.params.accountId);
+      return orders;
     }
   });
 
@@ -250,35 +181,14 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
       hide: false,
       tags: [ApiDocsTags.PkiAcme],
       description: "ACME Get Order - return status and details of the order",
-      params: z.object({
-        profileId: z.string().uuid(),
-        orderId: z.string()
-      }),
+      ...GetAcmeOrderSchema.shape,
       response: {
-        200: z.object({
-          status: z.string(),
-          expires: z.string().optional(),
-          identifiers: z.array(
-            z.object({
-              type: z.string(),
-              value: z.string()
-            })
-          ),
-          authorizations: z.array(z.string()),
-          finalize: z.string(),
-          certificate: z.string().optional()
-        })
+        200: GetAcmeOrderResponseSchema
       }
     },
     handler: async (req) => {
-      // FIXME: Implement ACME get order
-      return {
-        status: "pending",
-        expires: new Date(Date.now() + 24 * 60 * 60 * 1000).toISOString(),
-        identifiers: [],
-        authorizations: [],
-        finalize: `/api/v1/pki/acme/profiles/${req.params.profileId}/orders/${req.params.orderId}/finalize`
-      };
+      const order = await server.services.pkiAcme.getAcmeOrder(req.params.profileId, req.params.orderId);
+      return order;
     }
   });
 
@@ -294,39 +204,18 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
       hide: false,
       tags: [ApiDocsTags.PkiAcme],
       description: "ACME Finalize Order - finalize cert order by providing CSR",
-      params: z.object({
-        profileId: z.string().uuid(),
-        orderId: z.string()
-      }),
-      body: z.object({
-        csr: z.string()
-      }),
+      ...FinalizeAcmeOrderSchema.shape,
       response: {
-        200: z.object({
-          status: z.string(),
-          expires: z.string().optional(),
-          identifiers: z.array(
-            z.object({
-              type: z.string(),
-              value: z.string()
-            })
-          ),
-          authorizations: z.array(z.string()),
-          finalize: z.string(),
-          certificate: z.string().optional()
-        })
+        200: FinalizeAcmeOrderResponseSchema
       }
     },
     handler: async (req) => {
-      // FIXME: Implement ACME finalize order
-      return {
-        status: "processing",
-        expires: new Date(Date.now() + 24 * 60 * 60 * 1000).toISOString(),
-        identifiers: [],
-        authorizations: [],
-        finalize: `/api/v1/pki/acme/profiles/${req.params.profileId}/orders/${req.params.orderId}/finalize`,
-        certificate: `/api/v1/pki/acme/profiles/${req.params.profileId}/orders/${req.params.orderId}/certificate`
-      };
+      const order = await server.services.pkiAcme.finalizeAcmeOrder(
+        req.params.profileId,
+        req.params.orderId,
+        req.body.csr
+      );
+      return order;
     }
   });
 
@@ -342,18 +231,16 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
       hide: false,
       tags: [ApiDocsTags.PkiAcme],
       description: "ACME Download Certificate - download certificate when ready",
-      params: z.object({
-        profileId: z.string().uuid(),
-        orderId: z.string()
-      }),
+      ...DownloadAcmeCertificateSchema.shape,
       response: {
         200: z.string()
       }
     },
     handler: async (req, res) => {
-      // FIXME: Implement ACME certificate download
-      // Return the certificate in PEM format
-      const certificate = "FIXME-certificate-pem";
+      const certificate = await server.services.pkiAcme.downloadAcmeCertificate(
+        req.params.profileId,
+        req.params.orderId
+      );
       res.header("Content-Type", "application/pem-certificate-chain");
       return certificate;
     }
@@ -371,48 +258,14 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
       hide: false,
       tags: [ApiDocsTags.PkiAcme],
       description: "ACME Identifier Authorization - get authorization info (challenges)",
-      params: z.object({
-        profileId: z.string().uuid(),
-        authzId: z.string()
-      }),
+      ...GetAcmeAuthorizationSchema.shape,
       response: {
-        200: z.object({
-          status: z.string(),
-          expires: z.string().optional(),
-          identifier: z.object({
-            type: z.string(),
-            value: z.string()
-          }),
-          challenges: z.array(
-            z.object({
-              type: z.string(),
-              url: z.string(),
-              status: z.string(),
-              token: z.string(),
-              validated: z.string().optional()
-            })
-          )
-        })
+        200: GetAcmeAuthorizationResponseSchema
       }
     },
     handler: async (req) => {
-      // FIXME: Implement ACME authorization retrieval
-      return {
-        status: "pending",
-        expires: new Date(Date.now() + 24 * 60 * 60 * 1000).toISOString(),
-        identifier: {
-          type: "dns",
-          value: "FIXME-domain-name"
-        },
-        challenges: [
-          {
-            type: "http-01",
-            url: `/api/v1/pki/acme/profiles/${req.params.profileId}/authorizations/${req.params.authzId}/challenges/http-01`,
-            status: "pending",
-            token: "FIXME-challenge-token"
-          }
-        ]
-      };
+      const authz = await server.services.pkiAcme.getAcmeAuthorization(req.params.profileId, req.params.authzId);
+      return authz;
     }
   });
 
@@ -428,36 +281,14 @@ export const registerPkiAcmeRouter = async (server: FastifyZodProvider) => {
       hide: false,
       tags: [ApiDocsTags.PkiAcme],
       description: "ACME Respond to Challenge - let ACME server know challenge is ready",
-      params: z.object({
-        profileId: z.string().uuid(),
-        authzId: z.string()
-      }),
+      ...RespondToAcmeChallengeSchema.shape,
       response: {
-        200: z.object({
-          type: z.string(),
-          url: z.string(),
-          status: z.string(),
-          token: z.string(),
-          validated: z.string().optional(),
-          error: z
-            .object({
-              type: z.string(),
-              detail: z.string(),
-              status: z.number()
-            })
-            .optional()
-        })
+        200: RespondToAcmeChallengeResponseSchema
       }
     },
     handler: async (req) => {
-      // FIXME: Implement ACME challenge response
-      // Trigger verification process
-      return {
-        type: "http-01",
-        url: `/api/v1/pki/acme/profiles/${req.params.profileId}/authorizations/${req.params.authzId}/challenges/http-01`,
-        status: "pending",
-        token: "FIXME-challenge-token"
-      };
+      const challenge = await server.services.pkiAcme.respondToAcmeChallenge(req.params.profileId, req.params.authzId);
+      return challenge;
     }
   });
 };
diff --git a/backend/src/ee/services/pki-acme/pki-acme-schemas.ts b/backend/src/ee/services/pki-acme/pki-acme-schemas.ts
new file mode 100644
index 000000000..6cfee8ecc
--- /dev/null
+++ b/backend/src/ee/services/pki-acme/pki-acme-schemas.ts
@@ -0,0 +1,210 @@
+import { z } from "zod";
+
+// Directory endpoint
+export const GetAcmeDirectorySchema = z.object({
+  params: z.object({
+    profileId: z.string().uuid()
+  })
+});
+
+export const GetAcmeDirectoryResponseSchema = z.object({
+  newNonce: z.string(),
+  newAccount: z.string(),
+  newOrder: z.string(),
+  revokeCert: z.string()
+});
+
+// New Nonce endpoint
+export const GetAcmeNewNonceSchema = z.object({
+  params: z.object({
+    profileId: z.string().uuid()
+  })
+});
+
+// New Account endpoint
+export const CreateAcmeAccountSchema = z.object({
+  params: z.object({
+    profileId: z.string().uuid()
+  }),
+  body: z.object({
+    contact: z.array(z.string()).optional(),
+    termsOfServiceAgreed: z.boolean().optional(),
+    onlyReturnExisting: z.boolean().optional(),
+    externalAccountBinding: z
+      .object({
+        protected: z.string(),
+        payload: z.string(),
+        signature: z.string()
+      })
+      .optional()
+  })
+});
+
+export const CreateAcmeAccountResponseSchema = z.object({
+  status: z.string(),
+  contact: z.array(z.string()).optional(),
+  orders: z.string().optional(),
+  accountUrl: z.string()
+});
+
+// New Order endpoint
+export const CreateAcmeOrderSchema = z.object({
+  params: z.object({
+    profileId: z.string().uuid()
+  }),
+  body: z.object({
+    identifiers: z.array(
+      z.object({
+        type: z.string(),
+        value: z.string()
+      })
+    ),
+    notBefore: z.string().optional(),
+    notAfter: z.string().optional()
+  })
+});
+
+export const CreateAcmeOrderResponseSchema = z.object({
+  status: z.string(),
+  expires: z.string(),
+  identifiers: z.array(
+    z.object({
+      type: z.string(),
+      value: z.string()
+    })
+  ),
+  authorizations: z.array(z.string()),
+  finalize: z.string(),
+  certificate: z.string().optional()
+});
+
+// Account Deactivation endpoint
+export const DeactivateAcmeAccountSchema = z.object({
+  params: z.object({
+    profileId: z.string().uuid(),
+    accountId: z.string()
+  }),
+  body: z.object({
+    status: z.literal("deactivated")
+  })
+});
+
+export const DeactivateAcmeAccountResponseSchema = z.object({
+  status: z.string()
+});
+
+// List Orders endpoint
+export const ListAcmeOrdersSchema = z.object({
+  params: z.object({
+    profileId: z.string().uuid(),
+    accountId: z.string()
+  })
+});
+
+export const ListAcmeOrdersResponseSchema = z.object({
+  orders: z.array(z.string())
+});
+
+// Get Order endpoint
+export const GetAcmeOrderSchema = z.object({
+  params: z.object({
+    profileId: z.string().uuid(),
+    orderId: z.string()
+  })
+});
+
+export const GetAcmeOrderResponseSchema = z.object({
+  status: z.string(),
+  expires: z.string().optional(),
+  identifiers: z.array(
+    z.object({
+      type: z.string(),
+      value: z.string()
+    })
+  ),
+  authorizations: z.array(z.string()),
+  finalize: z.string(),
+  certificate: z.string().optional()
+});
+
+// Finalize Order endpoint
+export const FinalizeAcmeOrderSchema = z.object({
+  params: z.object({
+    profileId: z.string().uuid(),
+    orderId: z.string()
+  }),
+  body: z.object({
+    csr: z.string()
+  })
+});
+
+export const FinalizeAcmeOrderResponseSchema = z.object({
+  status: z.string(),
+  expires: z.string().optional(),
+  identifiers: z.array(
+    z.object({
+      type: z.string(),
+      value: z.string()
+    })
+  ),
+  authorizations: z.array(z.string()),
+  finalize: z.string(),
+  certificate: z.string().optional()
+});
+
+// Download Certificate endpoint
+export const DownloadAcmeCertificateSchema = z.object({
+  params: z.object({
+    profileId: z.string().uuid(),
+    orderId: z.string()
+  })
+});
+
+// Get Authorization endpoint
+export const GetAcmeAuthorizationSchema = z.object({
+  params: z.object({
+    profileId: z.string().uuid(),
+    authzId: z.string()
+  })
+});
+
+export const GetAcmeAuthorizationResponseSchema = z.object({
+  status: z.string(),
+  expires: z.string().optional(),
+  identifier: z.object({
+    type: z.string(),
+    value: z.string()
+  }),
+  challenges: z.array(
+    z.object({
+      type: z.string(),
+      url: z.string(),
+      status: z.string(),
+      token: z.string(),
+      validated: z.string().optional()
+    })
+  )
+});
+
+// Respond to Challenge endpoint
+export const RespondToAcmeChallengeSchema = z.object({
+  params: z.object({
+    profileId: z.string().uuid(),
+    authzId: z.string()
+  })
+});
+
+export const RespondToAcmeChallengeResponseSchema = z.object({
+  type: z.string(),
+  url: z.string(),
+  status: z.string(),
+  token: z.string(),
+  validated: z.string().optional(),
+  error: z
+    .object({
+      type: z.string(),
+      detail: z.string(),
+      status: z.number()
+    })
+    .optional()
+});
diff --git a/backend/src/ee/services/pki-acme/pki-acme-service.ts b/backend/src/ee/services/pki-acme/pki-acme-service.ts
new file mode 100644
index 000000000..1ece387e0
--- /dev/null
+++ b/backend/src/ee/services/pki-acme/pki-acme-service.ts
@@ -0,0 +1,168 @@
+import { NotFoundError } from "@app/lib/errors";
+
+import { TCertificateProfileDALFactory } from "@app/services/certificate-profile/certificate-profile-dal";
+
+import {
+  TCreateAcmeAccountResponse,
+  TCreateAcmeOrderResponse,
+  TDeactivateAcmeAccountResponse,
+  TDownloadAcmeCertificateDTO,
+  TFinalizeAcmeOrderResponse,
+  TGetAcmeAuthorizationResponse,
+  TGetAcmeDirectoryResponse,
+  TGetAcmeOrderResponse,
+  TListAcmeOrdersResponse,
+  TPkiAcmeServiceFactory,
+  TRespondToAcmeChallengeResponse
+} from "./pki-acme-types";
+
+type TPkiAcmeServiceFactoryDep = {
+  certificateProfileDAL: Pick<TCertificateProfileDALFactory, "findById">;
+};
+
+export const pkiAcmeServiceFactory = ({ certificateProfileDAL }: TPkiAcmeServiceFactoryDep): TPkiAcmeServiceFactory => {
+  const getAcmeDirectory = async (profileId: string): Promise<TGetAcmeDirectoryResponse> => {
+    // FIXME: Implement ACME directory endpoint
+    // Validate profile exists and is for ACME enrollment
+    const profile = await certificateProfileDAL.findById(profileId);
+    if (!profile) {
+      throw new NotFoundError({ message: "Certificate profile not found" });
+    }
+
+    // FIXME: Validate profile is configured for ACME enrollment
+    return {
+      newNonce: `/api/v1/pki/acme/profiles/${profileId}/new-nonce`,
+      newAccount: `/api/v1/pki/acme/profiles/${profileId}/new-account`,
+      newOrder: `/api/v1/pki/acme/profiles/${profileId}/new-order`,
+      revokeCert: `/api/v1/pki/acme/profiles/${profileId}/revoke-cert`
+    };
+  };
+
+  const getAcmeNewNonce = async (profileId: string): Promise<string> => {
+    // FIXME: Implement ACME new nonce generation
+    // Generate a new nonce, store it, and return it
+    return "FIXME-generate-nonce";
+  };
+
+  const createAcmeAccount = async (profileId: string, body: unknown): Promise<TCreateAcmeAccountResponse> => {
+    // FIXME: Implement ACME new account registration
+    // Use EAB authentication to find corresponding Infisical machine identity
+    // Check permissions and return account information
+    return {
+      status: "valid",
+      accountUrl: `/api/v1/pki/acme/profiles/${profileId}/accounts/FIXME-account-id`,
+      contact: [],
+      orders: `/api/v1/pki/acme/profiles/${profileId}/accounts/FIXME-account-id/orders`
+    };
+  };
+
+  const createAcmeOrder = async (profileId: string, body: unknown): Promise<TCreateAcmeOrderResponse> => {
+    // FIXME: Implement ACME new order creation
+    const orderId = "FIXME-order-id";
+    return {
+      status: "pending",
+      expires: new Date(Date.now() + 24 * 60 * 60 * 1000).toISOString(),
+      identifiers: [],
+      authorizations: [],
+      finalize: `/api/v1/pki/acme/profiles/${profileId}/orders/${orderId}/finalize`
+    };
+  };
+
+  const deactivateAcmeAccount = async (
+    profileId: string,
+    accountId: string
+  ): Promise<TDeactivateAcmeAccountResponse> => {
+    // FIXME: Implement ACME account deactivation
+    return {
+      status: "deactivated"
+    };
+  };
+
+  const listAcmeOrders = async (profileId: string, accountId: string): Promise<TListAcmeOrdersResponse> => {
+    // FIXME: Implement ACME list orders
+    return {
+      orders: []
+    };
+  };
+
+  const getAcmeOrder = async (profileId: string, orderId: string): Promise<TGetAcmeOrderResponse> => {
+    // FIXME: Implement ACME get order
+    return {
+      status: "pending",
+      expires: new Date(Date.now() + 24 * 60 * 60 * 1000).toISOString(),
+      identifiers: [],
+      authorizations: [],
+      finalize: `/api/v1/pki/acme/profiles/${profileId}/orders/${orderId}/finalize`
+    };
+  };
+
+  const finalizeAcmeOrder = async (
+    profileId: string,
+    orderId: string,
+    csr: string
+  ): Promise<TFinalizeAcmeOrderResponse> => {
+    // FIXME: Implement ACME finalize order
+    return {
+      status: "processing",
+      expires: new Date(Date.now() + 24 * 60 * 60 * 1000).toISOString(),
+      identifiers: [],
+      authorizations: [],
+      finalize: `/api/v1/pki/acme/profiles/${profileId}/orders/${orderId}/finalize`,
+      certificate: `/api/v1/pki/acme/profiles/${profileId}/orders/${orderId}/certificate`
+    };
+  };
+
+  const downloadAcmeCertificate = async (profileId: string, orderId: string): Promise<string> => {
+    // FIXME: Implement ACME certificate download
+    // Return the certificate in PEM format
+    return "FIXME-certificate-pem";
+  };
+
+  const getAcmeAuthorization = async (profileId: string, authzId: string): Promise<TGetAcmeAuthorizationResponse> => {
+    // FIXME: Implement ACME authorization retrieval
+    return {
+      status: "pending",
+      expires: new Date(Date.now() + 24 * 60 * 60 * 1000).toISOString(),
+      identifier: {
+        type: "dns",
+        value: "FIXME-domain-name"
+      },
+      challenges: [
+        {
+          type: "http-01",
+          url: `/api/v1/pki/acme/profiles/${profileId}/authorizations/${authzId}/challenges/http-01`,
+          status: "pending",
+          token: "FIXME-challenge-token"
+        }
+      ]
+    };
+  };
+
+  const respondToAcmeChallenge = async (
+    profileId: string,
+    authzId: string
+  ): Promise<TRespondToAcmeChallengeResponse> => {
+    // FIXME: Implement ACME challenge response
+    // Trigger verification process
+    return {
+      type: "http-01",
+      url: `/api/v1/pki/acme/profiles/${profileId}/authorizations/${authzId}/challenges/http-01`,
+      status: "pending",
+      token: "FIXME-challenge-token"
+    };
+  };
+
+  return {
+    getAcmeDirectory,
+    getAcmeNewNonce,
+    createAcmeAccount,
+    createAcmeOrder,
+    deactivateAcmeAccount,
+    listAcmeOrders,
+    getAcmeOrder,
+    finalizeAcmeOrder,
+    downloadAcmeCertificate,
+    getAcmeAuthorization,
+    respondToAcmeChallenge
+  };
+};
diff --git a/backend/src/ee/services/pki-acme/pki-acme-types.ts b/backend/src/ee/services/pki-acme/pki-acme-types.ts
new file mode 100644
index 000000000..4a80ab0f6
--- /dev/null
+++ b/backend/src/ee/services/pki-acme/pki-acme-types.ts
@@ -0,0 +1,38 @@
+import { z } from "zod";
+
+import {
+  CreateAcmeAccountResponseSchema,
+  CreateAcmeOrderResponseSchema,
+  DeactivateAcmeAccountResponseSchema,
+  FinalizeAcmeOrderResponseSchema,
+  GetAcmeAuthorizationResponseSchema,
+  GetAcmeDirectoryResponseSchema,
+  GetAcmeOrderResponseSchema,
+  ListAcmeOrdersResponseSchema,
+  RespondToAcmeChallengeResponseSchema
+} from "./pki-acme-schemas";
+
+export type TGetAcmeDirectoryResponse = z.infer<typeof GetAcmeDirectoryResponseSchema>;
+export type TCreateAcmeAccountResponse = z.infer<typeof CreateAcmeAccountResponseSchema>;
+export type TCreateAcmeOrderResponse = z.infer<typeof CreateAcmeOrderResponseSchema>;
+export type TDeactivateAcmeAccountResponse = z.infer<typeof DeactivateAcmeAccountResponseSchema>;
+export type TListAcmeOrdersResponse = z.infer<typeof ListAcmeOrdersResponseSchema>;
+export type TGetAcmeOrderResponse = z.infer<typeof GetAcmeOrderResponseSchema>;
+export type TFinalizeAcmeOrderResponse = z.infer<typeof FinalizeAcmeOrderResponseSchema>;
+export type TDownloadAcmeCertificateDTO = string;
+export type TGetAcmeAuthorizationResponse = z.infer<typeof GetAcmeAuthorizationResponseSchema>;
+export type TRespondToAcmeChallengeResponse = z.infer<typeof RespondToAcmeChallengeResponseSchema>;
+
+export type TPkiAcmeServiceFactory = {
+  getAcmeDirectory: (profileId: string) => Promise<TGetAcmeDirectoryResponse>;
+  getAcmeNewNonce: (profileId: string) => Promise<string>;
+  createAcmeAccount: (profileId: string, body: unknown) => Promise<TCreateAcmeAccountResponse>;
+  createAcmeOrder: (profileId: string, body: unknown) => Promise<TCreateAcmeOrderResponse>;
+  deactivateAcmeAccount: (profileId: string, accountId: string) => Promise<TDeactivateAcmeAccountResponse>;
+  listAcmeOrders: (profileId: string, accountId: string) => Promise<TListAcmeOrdersResponse>;
+  getAcmeOrder: (profileId: string, orderId: string) => Promise<TGetAcmeOrderResponse>;
+  finalizeAcmeOrder: (profileId: string, orderId: string, csr: string) => Promise<TFinalizeAcmeOrderResponse>;
+  downloadAcmeCertificate: (profileId: string, orderId: string) => Promise<string>;
+  getAcmeAuthorization: (profileId: string, authzId: string) => Promise<TGetAcmeAuthorizationResponse>;
+  respondToAcmeChallenge: (profileId: string, authzId: string) => Promise<TRespondToAcmeChallengeResponse>;
+};
diff --git a/backend/src/server/routes/index.ts b/backend/src/server/routes/index.ts
index e2009e7fa..0e25e9aee 100644
--- a/backend/src/server/routes/index.ts
+++ b/backend/src/server/routes/index.ts
@@ -25,6 +25,7 @@ import { auditLogStreamServiceFactory } from "@app/ee/services/audit-log-stream/
 import { certificateAuthorityCrlDALFactory } from "@app/ee/services/certificate-authority-crl/certificate-authority-crl-dal";
 import { certificateAuthorityCrlServiceFactory } from "@app/ee/services/certificate-authority-crl/certificate-authority-crl-service";
 import { certificateEstServiceFactory } from "@app/ee/services/certificate-est/certificate-est-service";
+import { pkiAcmeServiceFactory } from "@app/ee/services/pki-acme/pki-acme-service";
 import { dynamicSecretDALFactory } from "@app/ee/services/dynamic-secret/dynamic-secret-dal";
 import { dynamicSecretServiceFactory } from "@app/ee/services/dynamic-secret/dynamic-secret-service";
 import { buildDynamicSecretProviders } from "@app/ee/services/dynamic-secret/providers";
@@ -1161,6 +1162,10 @@ export const registerRoutes = async (
     projectDAL
   });
 
+  const pkiAcmeService = pkiAcmeServiceFactory({
+    certificateProfileDAL
+  });
+
   const pkiAlertService = pkiAlertServiceFactory({
     pkiAlertDAL,
     pkiCollectionDAL,
@@ -2436,6 +2441,7 @@ export const registerRoutes = async (
     certificateProfile: certificateProfileService,
     certificateAuthorityCrl: certificateAuthorityCrlService,
     certificateEst: certificateEstService,
+    pkiAcme: pkiAcmeService,
     pit: pitService,
     pkiAlert: pkiAlertService,
     pkiCollection: pkiCollectionService,