vercel-labs · felixarntz · Jun 22, 2026 · Jun 22, 2026
diff --git a/docs/guides/examples.md b/docs/guides/examples.md
@@ -99,7 +99,7 @@ Service factories must accept a typed config and return a typed service:
     "exportFunctions": [
       {
         "name": "create${serviceName.toPascalCase()}Service",
-        "receiveParamOfType": "${serviceName.toPascalCase()}Config",
+        "receiveParamsOfTypes": ["${serviceName.toPascalCase()}Config"],
         "returnValueOfType": "${serviceName.toPascalCase()}Service"
       }
     ]

diff --git a/docs/reference/path-patterns.md b/docs/reference/path-patterns.md
@@ -107,7 +107,9 @@ Templates work anywhere a string appears in `must` or `mustNot`:
     "exportFunctions": [
       {
         "name": "create${adapterName.toPascalCase()}Adapter",
-        "receiveParamOfType": "${adapterName.toPascalCase()}AdapterConfig",
+        "receiveParamsOfTypes": [
+          "${adapterName.toPascalCase()}AdapterConfig"
+        ],
         "returnValueOfType": "${adapterName.toPascalCase()}Adapter"
       }
     ]

diff --git a/docs/reference/predicates.md b/docs/reference/predicates.md
@@ -108,14 +108,14 @@ Assert local `const` declarations.
 
 ### `declareFunctions`
 
-Assert local function declarations. Optionally validate parameter and return type, using the same fields as `exportFunctions`.
+Assert local function declarations. Optionally validate parameters and return type, using the same fields as `exportFunctions`.
 
 ```json
 "must": {
   "declareFunctions": [
     {
       "name": "createInternalClient",
-      "receiveParamOfType": "ClientConfig",
+      "receiveParamsOfTypes": ["ClientConfig"],
       "returnValueOfType": "Client"
     }
   ]
@@ -222,14 +222,14 @@ Assert `const` exports specifically. Stricter than `export` — a `function` or
 
 ### `exportFunctions`
 
-Assert function exports. Optionally validate the parameter and return type.
+Assert function exports. Optionally validate parameters and return type.
 
 ```json
 "must": {
   "exportFunctions": [
     {
       "name": "create${serviceName.toPascalCase()}Service",
-      "receiveParamOfType": "${serviceName.toPascalCase()}Config",
+      "receiveParamsOfTypes": ["${serviceName.toPascalCase()}Config"],
       "returnValueOfType": "${serviceName.toPascalCase()}Service"
     }
   ]
@@ -239,7 +239,8 @@ Assert function exports. Optionally validate the parameter and return type.
 | Field | Type | Description |
 | --- | --- | --- |
 | `name` | string | The function name. Templates allowed. |
-| `receiveParamOfType` | string | Optional. Type the first parameter must have. |
+| `receiveParamsOfTypes` | string[] | Optional. Ordered parameter types to enforce by index. Extra function parameters are allowed. |
+| `receiveParamOfType` | string | Deprecated. Optional type at least one parameter must have. Use `receiveParamsOfTypes` instead. |
 | `returnValueOfType` | string | Optional. Type the return value must have. |
 
 The bare-string form (`"exportFunctions": ["myFunction"]`) checks existence only.

diff --git a/e2e/fixtures/class-and-function-contracts-broken/konsistent.json b/e2e/fixtures/class-and-function-contracts-broken/konsistent.json
@@ -22,7 +22,9 @@
         "exportFunctions": [
           {
             "name": "create${adapterName.toPascalCase()}Adapter",
-            "receiveParamOfType": "${adapterName.toPascalCase()}AdapterConfig",
+            "receiveParamsOfTypes": [
+              "${adapterName.toPascalCase()}AdapterConfig"
+            ],
             "returnValueOfType": "${adapterName.toPascalCase()}Adapter"
           }
         ],

diff --git a/e2e/fixtures/class-and-function-contracts/konsistent.json b/e2e/fixtures/class-and-function-contracts/konsistent.json
@@ -22,7 +22,9 @@
         "exportFunctions": [
           {
             "name": "create${adapterName.toPascalCase()}Adapter",
-            "receiveParamOfType": "${adapterName.toPascalCase()}AdapterConfig",
+            "receiveParamsOfTypes": [
+              "${adapterName.toPascalCase()}AdapterConfig"
+            ],
             "returnValueOfType": "${adapterName.toPascalCase()}Adapter"
           }
         ],

diff --git a/e2e/fixtures/declaration-predicates-broken/konsistent-reverse.json b/e2e/fixtures/declaration-predicates-broken/konsistent-reverse.json
@@ -10,7 +10,7 @@
         "declareFunctions": [
           {
             "name": "createLocal",
-            "receiveParamOfType": "LocalConfig",
+            "receiveParamsOfTypes": ["LocalConfig"],
             "returnValueOfType": "LocalResult"
           }
         ],

diff --git a/e2e/fixtures/declaration-predicates-broken/konsistent.json b/e2e/fixtures/declaration-predicates-broken/konsistent.json
@@ -10,7 +10,7 @@
         "declareFunctions": [
           {
             "name": "createLocal",
-            "receiveParamOfType": "LocalConfig",
+            "receiveParamsOfTypes": ["LocalConfig"],
             "returnValueOfType": "LocalResult"
           }
         ],

diff --git a/e2e/fixtures/declaration-predicates/konsistent-reverse.json b/e2e/fixtures/declaration-predicates/konsistent-reverse.json
@@ -10,7 +10,7 @@
         "declareFunctions": [
           {
             "name": "createLocal",
-            "receiveParamOfType": "LocalConfig",
+            "receiveParamsOfTypes": ["LocalConfig"],
             "returnValueOfType": "LocalResult"
           }
         ],

diff --git a/e2e/fixtures/declaration-predicates/konsistent.json b/e2e/fixtures/declaration-predicates/konsistent.json
@@ -10,7 +10,7 @@
         "declareFunctions": [
           {
             "name": "createLocal",
-            "receiveParamOfType": "LocalConfig",
+            "receiveParamsOfTypes": ["LocalConfig"],
             "returnValueOfType": "LocalResult"
           }
         ],

diff --git a/e2e/fixtures/deprecated-function-param/konsistent.json b/e2e/fixtures/deprecated-function-param/konsistent.json
@@ -0,0 +1,16 @@
+{
+  "version": "v1",
+  "conventions": [
+    {
+      "paths": "index.ts",
+      "must": {
+        "exportFunctions": [
+          {
+            "name": "createThing",
+            "receiveParamOfType": "ThingConfig"
+          }
+        ]
+      }
+    }
+  ]
+}
diff --git a/e2e/fixtures/function-signatures-broken/konsistent.json b/e2e/fixtures/function-signatures-broken/konsistent.json
@@ -8,7 +8,10 @@
         "exportFunctions": [
           {
             "name": "create${serviceName.toPascalCase()}Service",
-            "receiveParamOfType": "${serviceName.toPascalCase()}Config",
+            "receiveParamsOfTypes": [
+              "${serviceName.toPascalCase()}Config",
+              "${serviceName.toPascalCase()}Logger"
+            ],
             "returnValueOfType": "${serviceName.toPascalCase()}Service"
           }
         ]

diff --git a/e2e/fixtures/function-signatures-broken/services/auth/index.ts b/e2e/fixtures/function-signatures-broken/services/auth/index.ts
@@ -1,9 +1,21 @@
 export interface Options {
   apiKey: string;
 }
+export interface AuthConfig {
+  apiKey: string;
+}
 export interface AuthService {
   authenticate(): Promise<void>;
 }
-export function createAuthService(config: Options): AuthService {
+export interface AuthLogger {
+  info(message: string): void;
+}
+export function createAuthService(
+  config: AuthConfig,
+  logger: Options,
+  retryCount: number
+): AuthService {
+  logger.apiKey;
+  retryCount;
   return { authenticate: async () => {} };
 }
diff --git a/e2e/fixtures/function-signatures-broken/services/payments/index.ts b/e2e/fixtures/function-signatures-broken/services/payments/index.ts
@@ -4,6 +4,13 @@ export interface PaymentsConfig {
 export interface PaymentsService {
   charge(): Promise<void>;
 }
-export function createPaymentsService(config: PaymentsConfig): any {
+export interface PaymentsLogger {
+  info(message: string): void;
+}
+export function createPaymentsService(
+  config: PaymentsConfig,
+  logger: PaymentsLogger
+): any {
+  logger.info(config.apiKey);
   return { charge: async () => {} };
 }
diff --git a/e2e/fixtures/function-signatures/konsistent.json b/e2e/fixtures/function-signatures/konsistent.json
@@ -8,7 +8,10 @@
         "exportFunctions": [
           {
             "name": "create${serviceName.toPascalCase()}Service",
-            "receiveParamOfType": "${serviceName.toPascalCase()}Config",
+            "receiveParamsOfTypes": [
+              "${serviceName.toPascalCase()}Config",
+              "${serviceName.toPascalCase()}Logger"
+            ],
             "returnValueOfType": "${serviceName.toPascalCase()}Service"
           }
         ]

diff --git a/e2e/fixtures/function-signatures/services/auth/index.ts b/e2e/fixtures/function-signatures/services/auth/index.ts
@@ -4,6 +4,14 @@ export interface AuthConfig {
 export interface AuthService {
   authenticate(): Promise<void>;
 }
-export function createAuthService(config: AuthConfig): AuthService {
+export interface AuthLogger {
+  info(message: string): void;
+}
+export function createAuthService(
+  config: AuthConfig,
+  logger: AuthLogger,
+  retryCount: number
+): AuthService {
+  logger.info(`auth retries: ${retryCount}`);
   return { authenticate: async () => {} };
 }
diff --git a/e2e/fixtures/function-signatures/services/payments/index.ts b/e2e/fixtures/function-signatures/services/payments/index.ts
@@ -6,8 +6,14 @@ export interface PaymentsService<T> {
   client: T;
   charge(): Promise<void>;
 }
+export interface PaymentsLogger {
+  info(message: string): void;
+}
 export function createPaymentsService(
-  config: PaymentsConfig<string>
+  config: PaymentsConfig<string>,
+  logger: PaymentsLogger,
+  timeoutMs: number
 ): PaymentsService<string> {
+  logger.info(`payments timeout: ${timeoutMs}`);
   return { client: config.client, charge: async () => {} };
 }
diff --git a/e2e/placeholder.test.ts b/e2e/placeholder.test.ts
@@ -201,7 +201,7 @@ describe("function-signatures-broken fixture", () => {
       };
       expect(error.code ?? error.status).toBe(1);
       expect(error.stdout).toContain(
-        'Function "createAuthService" must receive a parameter of type "AuthConfig"'
+        'Function "createAuthService" parameter 2 must be of type "AuthLogger"'
       );
       expect(error.stdout).toContain(
         'Function "createPaymentsService" must return value of type "PaymentsService"'
@@ -212,6 +212,19 @@ describe("function-signatures-broken fixture", () => {
   });
 });
 
+describe("deprecated-function-param fixture", () => {
+  const cwd = resolve(fixturesDir, "deprecated-function-param");
+
+  it("konsistent validate exits 0 and warns for receiveParamOfType", async () => {
+    const { stdout, stderr } = await runCli({ args: ["validate"], cwd });
+    expect(stdout).toContain("Configuration is valid");
+    expect(stderr).toContain('"receiveParamOfType" is deprecated');
+    expect(stderr).toContain(
+      "conventions[0].must.exportFunctions[0].receiveParamOfType"
+    );
+  });
+});
+
 describe("ai-toolkit-broken-exports fixture", () => {
   const cwd = resolve(fixturesDir, "ai-toolkit-broken-exports");
 
@@ -300,7 +313,7 @@ describe("class-and-function-contracts-broken fixture", () => {
         'Class "DatabaseAdapter" must extend "BaseAdapter"'
       );
       expect(error.stdout).toContain(
-        'Function "createDatabaseAdapter" must receive a parameter of type "DatabaseAdapterConfig"'
+        'Function "createDatabaseAdapter" parameter 1 must be of type "DatabaseAdapterConfig"'
       );
       expect(error.stdout).toContain(
         'Function "createDatabaseAdapter" must return value of type "DatabaseAdapter"'

diff --git a/packages/convention/reusable-convention-package.schema.json b/packages/convention/reusable-convention-package.schema.json
@@ -156,6 +156,12 @@
                             "receiveParamOfType": {
                               "type": "string"
                             },
+                            "receiveParamsOfTypes": {
+                              "type": "array",
+                              "items": {
+                                "type": "string"
+                              }
+                            },
                             "returnValueOfType": {
                               "type": "string"
                             }
@@ -354,6 +360,12 @@
                             "receiveParamOfType": {
                               "type": "string"
                             },
+                            "receiveParamsOfTypes": {
+                              "type": "array",
+                              "items": {
+                                "type": "string"
+                              }
+                            },
                             "returnValueOfType": {
                               "type": "string"
                             }
@@ -603,6 +615,12 @@
                             "receiveParamOfType": {
                               "type": "string"
                             },
+                            "receiveParamsOfTypes": {
+                              "type": "array",
+                              "items": {
+                                "type": "string"
+                              }
+                            },
                             "returnValueOfType": {
                               "type": "string"
                             }
@@ -801,6 +819,12 @@
                             "receiveParamOfType": {
                               "type": "string"
                             },
+                            "receiveParamsOfTypes": {
+                              "type": "array",
+                              "items": {
+                                "type": "string"
+                              }
+                            },
                             "returnValueOfType": {
                               "type": "string"
                             }
@@ -1131,6 +1155,12 @@
                             "receiveParamOfType": {
                               "type": "string"
                             },
+                            "receiveParamsOfTypes": {
+                              "type": "array",
+                              "items": {
+                                "type": "string"
+                              }
+                            },
                             "returnValueOfType": {
                               "type": "string"
                             }
@@ -1329,6 +1359,12 @@
                             "receiveParamOfType": {
                               "type": "string"
                             },
+                            "receiveParamsOfTypes": {
+                              "type": "array",
+                              "items": {
+                                "type": "string"
+                              }
+                            },
                             "returnValueOfType": {
                               "type": "string"
                             }
@@ -1578,6 +1614,12 @@
                             "receiveParamOfType": {
                               "type": "string"
                             },
+                            "receiveParamsOfTypes": {
+                              "type": "array",
+                              "items": {
+                                "type": "string"
+                              }
+                            },
                             "returnValueOfType": {
                               "type": "string"
                             }
@@ -1776,6 +1818,12 @@
                             "receiveParamOfType": {
                               "type": "string"
                             },
+                            "receiveParamsOfTypes": {
+                              "type": "array",
+                              "items": {
+                                "type": "string"
+                              }
+                            },
                             "returnValueOfType": {
                               "type": "string"
                             }

diff --git a/packages/convention/src/index.test.ts b/packages/convention/src/index.test.ts
@@ -51,6 +51,7 @@ describe("ReusableConventionV1Schema", () => {
           {
             name: "createLocal",
             receiveParamOfType: "LocalConfig",
+            receiveParamsOfTypes: ["LocalConfig"],
             returnValueOfType: "Local",
           },
         ],

diff --git a/packages/convention/src/schemas.ts b/packages/convention/src/schemas.ts
@@ -16,7 +16,11 @@ export const ImportDefinitionV1Schema = z.strictObject({
 
 export const FunctionDefinitionV1Schema = z.strictObject({
   name: z.string(),
+  /**
+   * Deprecated: use receiveParamsOfTypes instead.
+   */
   receiveParamOfType: z.string().optional(),
+  receiveParamsOfTypes: z.array(z.string()).optional(),
   returnValueOfType: z.string().optional(),
 });