diff --git a/packages/jsonrpc/src/express.test.ts b/packages/jsonrpc/src/express.test.ts
index 69d2db2..2759682 100644
--- a/packages/jsonrpc/src/express.test.ts
+++ b/packages/jsonrpc/src/express.test.ts
@@ -6,6 +6,7 @@ import {createClient} from './supertest'
 import {ensure} from './ensure'
 import {jsonrpc} from './express'
 import {noopLogger} from './test-utils'
+import {Contextual} from './types'
 
 describe('jsonrpc', () => {
 
@@ -20,15 +21,15 @@ describe('jsonrpc', () => {
     asyncError(message: string): Promise<void>
     httpError(statusCode: number, message: string): Promise<void>
 
-    addWithContext(a: number, b: number): (ctx: IContext) => number
+    addWithContext(a: number, b: number): number
     addWithContext2(a: number, b: number): Promise<number>
   }
 
   const ensureLoggedIn = ensure<IContext>(c => !!c.userId)
 
-  class Service implements IService {
+  class Service implements Contextual<IService, IContext> {
     constructor(readonly time: number) {}
-    add(a: number, b: number) {
+    add(context: IContext, a: number, b: number) {
       return a + b
     }
     multiply(...numbers: number[]) {
@@ -39,13 +40,13 @@ describe('jsonrpc', () => {
         setTimeout(resolve, this.time)
       })
     }
-    syncError(message: string) {
+    syncError(context: IContext, message: string) {
       throw new Error(message)
     }
-    async asyncError(message: string) {
+    async asyncError(context: IContext, message: string) {
       throw new Error(message)
     }
-    async httpError(statusCode: number, message: string) {
+    async httpError(context: IContext, statusCode: number, message: string) {
       const err: any = new Error(message)
       err.statusCode = statusCode
       err.errors = [{
@@ -53,12 +54,12 @@ describe('jsonrpc', () => {
       }]
       throw err
     }
-    addWithContext = (a: number, b: number) => (ctx: IContext): number => {
+    addWithContext = (ctx: IContext, a: number, b: number) => {
       return a + b + ctx.userId
     }
 
     @ensureLoggedIn
-    addWithContext2(a: number, b: number, ctx?: IContext) {
+    addWithContext2(ctx: IContext, a: number, b: number) {
       return Promise.resolve(a + b + ctx!.userId)
     }
   }
diff --git a/packages/jsonrpc/src/jsonrpc.ts b/packages/jsonrpc/src/jsonrpc.ts
index 4e12505..7c80c7f 100644
--- a/packages/jsonrpc/src/jsonrpc.ts
+++ b/packages/jsonrpc/src/jsonrpc.ts
@@ -157,15 +157,7 @@ export const createRpcService = <T, M extends FunctionPropertyNames<T>>(
 
       await validateServiceContext(id, service, method, context)
 
-      // FIXME TODO if user specified too many parameters in the request,
-      // they might override the context argument! this is dangerous as it
-      // could allow them to set any userId they would like. We should compare
-      // method arguments length before invoking this function.
-      let retValue = (rpcService[method] as any)(...params, context)
-
-      if (typeof retValue === 'function') {
-        retValue = retValue(context)
-      }
+      let retValue = (rpcService[method] as any)(context, ...params)
 
       if (!isPromise(retValue) && isNotification) {
         return null
diff --git a/packages/jsonrpc/src/local.test.ts b/packages/jsonrpc/src/local.test.ts
index 52c2677..31629ad 100644
--- a/packages/jsonrpc/src/local.test.ts
+++ b/packages/jsonrpc/src/local.test.ts
@@ -1,11 +1,12 @@
 import {createLocalClient} from './local'
 import {keys} from 'ts-transformer-keys'
+import {Contextual, ReverseContextual, TAsyncified} from './types'
 
 describe('local', () => {
 
   interface IService {
     add(a: number, b: number): number
-    addWithContext(a: number, b: number): (context: IContext) => number
+    addWithContext(a: number, b: number): number
   }
   const IServiceKeys = keys<IService>()
 
@@ -13,19 +14,18 @@ describe('local', () => {
     userId: 1000
   }
 
-  class Service implements IService {
-    add(a: number, b: number) {
+  class Service implements Contextual<IService, IContext> {
+    add(cx: IContext, a: number, b: number) {
       return a + b
     }
-    addWithContext = (a: number, b: number) => (context: IContext) => {
-      return a + b + context.userId
+    addWithContext = (cx: IContext, a: number, b: number) => {
+      return a + b + cx.userId
     }
   }
 
   const service = new Service()
-  const proxy = createLocalClient<IService>(service, {
-    userId: 1000,
-  })
+
+  const proxy = createLocalClient(service, () => ({userId: 1000}))
 
   describe('add', () => {
     it('should add two numbers', async () => {
diff --git a/packages/jsonrpc/src/local.ts b/packages/jsonrpc/src/local.ts
index 2b199dd..2647fe8 100644
--- a/packages/jsonrpc/src/local.ts
+++ b/packages/jsonrpc/src/local.ts
@@ -1,21 +1,24 @@
-import {TAsyncified} from './types'
+import {TAsyncified, Contextual, ReverseContextual} from './types'
+import {Request} from 'express'
+import {TGetContext} from './express'
 
 /**
  * Creates a local client for a specific service instance. The actual service
  * will be invoked as if it would be remotely. This helps keep the API similar
  * on the client- and server-side.
  */
-export function createLocalClient<T>(service: T, context: any) {
+export function createLocalClient<T, Context>(
+  service: T,
+  getContext: () => Context,
+): TAsyncified<ReverseContextual<T>> {
   const proxy = new Proxy({}, {
     get(obj, prop) {
+      const context = getContext()
       return async function makeRequest(...args: any[]) {
-        const result = (service as any)[prop](...args)
-        if (typeof result === 'function') {
-          return result(context)
-        }
+        const result = (service as any)[prop](context, ...args)
         return result
       }
     },
   })
-  return proxy as TAsyncified<T>
+  return proxy as any
 }
diff --git a/packages/jsonrpc/src/redux.test.ts b/packages/jsonrpc/src/redux.test.ts
index 7078542..b788de5 100644
--- a/packages/jsonrpc/src/redux.test.ts
+++ b/packages/jsonrpc/src/redux.test.ts
@@ -6,7 +6,7 @@ import bodyParser from 'body-parser'
 import express from 'express'
 import {AddressInfo} from 'net'
 import {Server} from 'http'
-import {TPendingActions, TAllActions} from './types'
+import {Contextual, TPendingActions, TAllActions} from './types'
 import {combineReducers} from 'redux'
 import {createActions, createReducer} from './redux'
 import {createRemoteClient} from './remote'
@@ -21,9 +21,8 @@ describe('createActions', () => {
     add(a: number, b: number): number
     addAsync(a: number, b: number): Promise<number>
     addStringsAsync(a: string, b: string): Promise<string>
-    addWithContext(a: number, b: number): (ctx: IContext) => number
-    addAsyncWithContext(a: number, b: number): (ctx: IContext) =>
-      Promise<number>
+    addWithContext(a: number, b: number): number
+    addAsyncWithContext(a: number, b: number): Promise<number>
     throwError(bool: boolean): boolean
   }
 
@@ -31,21 +30,21 @@ describe('createActions', () => {
     userId: number
   }
 
-  class Service implements IService {
-    add(a: number, b: number) {
+  class Service implements Contextual<IService, IContext> {
+    add(cx: IContext, a: number, b: number) {
       return a + b
     }
-    addAsync(a: number, b: number) {
+    addAsync(cx: IContext, a: number, b: number) {
       return new Promise<number>(resolve => resolve(a + b))
     }
-    addStringsAsync(a: string, b: string) {
+    addStringsAsync(cx: IContext, a: string, b: string) {
       return new Promise<string>(resolve => resolve(a + b))
     }
-    addWithContext = (a: number, b: number) => (ctx: IContext) =>
-      a + b + ctx.userId
-    addAsyncWithContext = (a: number, b: number) => (ctx: IContext) =>
-      new Promise<number>(resolve => resolve(a + b + ctx.userId))
-    throwError(bool: boolean) {
+    addWithContext = (cx: IContext, a: number, b: number) =>
+      a + b + cx.userId
+    addAsyncWithContext = (cx: IContext, a: number, b: number) =>
+      new Promise<number>(resolve => resolve(a + b + cx.userId))
+    throwError(cx: IContext, bool: boolean) {
       if (bool) {
         throw new Error('test')
       }
diff --git a/packages/jsonrpc/src/remote.test.ts b/packages/jsonrpc/src/remote.test.ts
index d1d3e2f..cafe46a 100644
--- a/packages/jsonrpc/src/remote.test.ts
+++ b/packages/jsonrpc/src/remote.test.ts
@@ -10,6 +10,7 @@ import {createRemoteClient} from './remote'
 import {jsonrpc} from './express'
 import {keys} from 'ts-transformer-keys'
 import {noopLogger} from './test-utils'
+import {Contextual} from './types'
 
 describe('remote', () => {
 
@@ -20,11 +21,11 @@ describe('remote', () => {
   }
   const IServiceKeys = keys<IService>()
 
-  class Service implements IService {
-    add(a: number, b: number) {
+  class Service implements Contextual<IService, {}> {
+    add(ctx: {}, a: number, b: number) {
       return a + b
     }
-    async fetchItem(obj1: {a: number}, obj2: {b: number})
+    async fetchItem(ctx: {}, obj1: {a: number}, obj2: {b: number})
       : Promise<{a: number, b: number}> {
       return Promise.resolve({...obj1, ...obj2})
     }
diff --git a/packages/jsonrpc/src/types.ts b/packages/jsonrpc/src/types.ts
index 8497030..309890d 100644
--- a/packages/jsonrpc/src/types.ts
+++ b/packages/jsonrpc/src/types.ts
@@ -3,11 +3,10 @@ import {IPendingAction, IResolvedAction, IRejectedAction} from '@rondo.dev/clien
 export type ArgumentTypes<T> =
   T extends (...args: infer U) => infer R ? U : never
 export type RetType<T> = T extends (...args: any[]) => infer R ? R : never
-type UnwrapHOC<T> = T extends (...args: any[]) => infer R ? R : T
 type UnwrapPromise<T> = T extends Promise<infer V> ? V : T
 type RetProm<T> = T extends Promise<any> ? T : Promise<T>
 type PromisifyReturnType<T> = (...a: ArgumentTypes<T>) =>
-  RetProm<UnwrapHOC<RetType<T>>>
+  RetProm<RetType<T>>
 
 /**
  * Helps implement a service from a service definiton that has a context as a
@@ -15,16 +14,15 @@ type PromisifyReturnType<T> = (...a: ArgumentTypes<T>) =>
  */
 export type Contextual<T, Cx> = {
   [K in keyof T]:
-    T[K] extends () => infer R
-      ? (cx: Cx) => R :
-    T[K] extends (a: infer A) => infer R
-      ? (a: A, cx: Cx) => R :
-    T[K] extends (a: infer A, b: infer B) => infer R
-      ? (a: A, b: B, cx: Cx) => R :
-    T[K] extends (a: infer A, b: infer B, c: infer C) => infer R
-      ? (a: A, b: B, c: C, cx: Cx) => R :
-    T[K] extends (a: infer A, b: infer B, c: infer C, d: infer D) => infer R
-      ? (a: A, b: B, c: C, d: D, cx: Cx) => R :
+    T[K] extends (...args: infer A) => infer R
+      ? (cx: Cx, ...args: A) => R :
+    never
+}
+
+export type ReverseContextual<T> = {
+  [K in keyof T]:
+    T[K] extends (cx: any, ...args: infer A) => infer R
+      ? (...args: A) => R :
     never
 }
 
@@ -46,7 +44,7 @@ export interface IReduxed<ActionType extends string> {
 
 export type TReduxed<T, ActionType extends string> = {
   [K in keyof T]: (...a: ArgumentTypes<T[K]>) =>
-    IRPCPendingAction<UnwrapPromise<UnwrapHOC<RetType<T[K]>>>, ActionType, K>
+    IRPCPendingAction<UnwrapPromise<RetType<T[K]>>, ActionType, K>
 }
 
 export type TReduxHandlers<T, State> = {