diff --git a/docs/mammon-api.yml b/docs/mammon-api.yml
new file mode 100644
index 0000000..f3de671
--- /dev/null
+++ b/docs/mammon-api.yml
@@ -0,0 +1,365 @@
+openapi: 3.1.0
+info:
+  title: OpenAPI definition
+  version: v0
+servers:
+- url: http://localhost:8080
+  description: Generated server url
+paths:
+  /ledgers/main/{ledgerId}:
+    put:
+      tags:
+      - ledger-controller
+      operationId: updateMainLedger
+      parameters:
+      - name: ledgerId
+        in: path
+        required: true
+        schema:
+          type: string
+          format: uuid
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/UpdateMainLedgerRequest"
+        required: true
+      responses:
+        "404":
+          description: Not Found
+        "400":
+          description: Bad Request
+        "200":
+          description: OK
+          content:
+            '*/*':
+              schema:
+                $ref: "#/components/schemas/MainLedgerResponse"
+  /ledgers/combined/{ledgerId}:
+    put:
+      tags:
+      - ledger-controller
+      operationId: updateCombinedLedger
+      parameters:
+      - name: ledgerId
+        in: path
+        required: true
+        schema:
+          type: string
+          format: uuid
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/UpdateCombinedLedgerRequest"
+        required: true
+      responses:
+        "404":
+          description: Not Found
+        "400":
+          description: Bad Request
+        "200":
+          description: OK
+          content:
+            '*/*':
+              schema:
+                $ref: "#/components/schemas/CombinedLedgerResponse"
+  /ledgers/main:
+    post:
+      tags:
+      - ledger-controller
+      operationId: createMainLedger
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/CreateMainLedgerRequest"
+        required: true
+      responses:
+        "404":
+          description: Not Found
+        "400":
+          description: Bad Request
+        "200":
+          description: OK
+          content:
+            '*/*':
+              schema:
+                $ref: "#/components/schemas/MainLedgerResponse"
+  /ledgers/combined:
+    post:
+      tags:
+      - ledger-controller
+      operationId: createCombinedLedger
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/CreateCombinedLedgerRequest"
+        required: true
+      responses:
+        "404":
+          description: Not Found
+        "400":
+          description: Bad Request
+        "200":
+          description: OK
+          content:
+            '*/*':
+              schema:
+                $ref: "#/components/schemas/CombinedLedgerResponse"
+  /activity/fetch/{characterId}:
+    post:
+      tags:
+      - activity-controller
+      operationId: fetchNewActivitiesForCharacter
+      parameters:
+      - name: characterId
+        in: path
+        required: true
+        schema:
+          type: integer
+          format: int64
+      responses:
+        "404":
+          description: Not Found
+        "400":
+          description: Bad Request
+        "200":
+          description: OK
+  /ledgers:
+    get:
+      tags:
+      - ledger-controller
+      operationId: findAll
+      responses:
+        "404":
+          description: Not Found
+        "400":
+          description: Bad Request
+        "200":
+          description: OK
+          content:
+            '*/*':
+              schema:
+                type: array
+                items:
+                  oneOf:
+                  - $ref: "#/components/schemas/CombinedLedgerResponse"
+                  - $ref: "#/components/schemas/MainLedgerResponse"
+  /ledgers/{ledgerId}:
+    get:
+      tags:
+      - ledger-controller
+      operationId: findById
+      parameters:
+      - name: ledgerId
+        in: path
+        required: true
+        schema:
+          type: string
+          format: uuid
+      responses:
+        "404":
+          description: Not Found
+        "400":
+          description: Bad Request
+        "200":
+          description: OK
+          content:
+            '*/*':
+              schema:
+                oneOf:
+                - $ref: "#/components/schemas/CombinedLedgerResponse"
+                - $ref: "#/components/schemas/MainLedgerResponse"
+  /characters:
+    get:
+      tags:
+      - character-controller
+      operationId: getCharacters
+      responses:
+        "404":
+          description: Not Found
+        "400":
+          description: Bad Request
+        "200":
+          description: OK
+          content:
+            '*/*':
+              schema:
+                type: array
+                items:
+                  $ref: "#/components/schemas/CharacterResponse"
+  /characters/{characterId}/rule-book:
+    get:
+      tags:
+      - rule-book-controller
+      operationId: findByCharacterId
+      parameters:
+      - name: characterId
+        in: path
+        required: true
+        schema:
+          type: integer
+          format: int64
+      responses:
+        "404":
+          description: Not Found
+        "400":
+          description: Bad Request
+        "200":
+          description: OK
+          content:
+            '*/*':
+              schema:
+                $ref: "#/components/schemas/RuleBookResponse"
+components:
+  schemas:
+    UpdateMainLedgerRequest:
+      type: object
+      properties:
+        name:
+          type: string
+      required:
+      - name
+    MainLedgerResponse:
+      allOf:
+      - $ref: "#/components/schemas/LedgerResponse"
+      - type: object
+        properties:
+          ledgerId:
+            type: string
+            format: uuid
+          name:
+            type: string
+          balance:
+            type: number
+          type:
+            type: string
+            enum:
+            - MAIN
+      required:
+      - balance
+      - ledgerId
+      - name
+    UpdateCombinedLedgerRequest:
+      type: object
+      properties:
+        name:
+          type: string
+        memberLedgerIds:
+          type: array
+          items:
+            type: string
+            format: uuid
+      required:
+      - memberLedgerIds
+      - name
+    CombinedLedgerResponse:
+      allOf:
+      - $ref: "#/components/schemas/LedgerResponse"
+      - type: object
+        properties:
+          ledgerId:
+            type: string
+            format: uuid
+          name:
+            type: string
+          balance:
+            type: number
+          memberLedgerIds:
+            type: array
+            items:
+              type: string
+              format: uuid
+          type:
+            type: string
+            enum:
+            - COMBINED
+      required:
+      - balance
+      - ledgerId
+      - memberLedgerIds
+      - name
+    CreateMainLedgerRequest:
+      type: object
+      properties:
+        name:
+          type: string
+      required:
+      - name
+    CreateCombinedLedgerRequest:
+      type: object
+      properties:
+        name:
+          type: string
+        memberLedgerIds:
+          type: array
+          items:
+            type: string
+            format: uuid
+      required:
+      - memberLedgerIds
+      - name
+    LedgerResponse:
+      type: object
+      discriminator:
+        propertyName: type
+      properties:
+        type:
+          type: string
+          enum:
+          - MAIN
+          - COMBINED
+    CharacterResponse:
+      type: object
+      properties:
+        characterId:
+          type: integer
+          format: int64
+        name:
+          type: string
+      required:
+      - characterId
+      - name
+    RuleBookResponse:
+      type: object
+      properties:
+        characterId:
+          type: integer
+          format: int64
+        ruleSets:
+          type: object
+          additionalProperties:
+            $ref: "#/components/schemas/RuleSetResponse"
+      required:
+      - characterId
+      - ruleSets
+    RuleResponse:
+      type: object
+      properties:
+        rate:
+          type: string
+          enum:
+          - NONE
+          - VALUE
+          - JITA_BUY
+          - JITA_SELL
+          - EVE_ESTIMATE
+        fromLedgerId:
+          type: string
+          format: uuid
+        toLedgerId:
+          type: string
+          format: uuid
+      required:
+      - rate
+    RuleSetResponse:
+      type: object
+      properties:
+        rules:
+          type: array
+          items:
+            $ref: "#/components/schemas/RuleResponse"
+      required:
+      - rules
diff --git a/src/characters/chartacters.ts b/src/characters/chartacters.ts
index 63d4512..32a5f7b 100644
--- a/src/characters/chartacters.ts
+++ b/src/characters/chartacters.ts
@@ -8,7 +8,15 @@ export type Character = CharacterResponse
 export const useCharactersStore = defineStore('characters', () => {
     const characters = ref<Character[]>([]);
 
-    const findById = (characterId: number): Character | undefined => characters.value.find(c => c.characterId === characterId);
+    const findById = async (characterId: number): Promise<Character | undefined> => {
+        let character = characters.value.find(c => c.characterId === characterId);
+
+        if (!character) {
+            await refresh(); // TODO call api instead of refresh
+            character = characters.value.find(c => c.characterId === characterId);
+        }
+        return character;
+    }
 
     const refresh = () => characterControllerApi.getCharacters().then(response => characters.value = response.data);
 
diff --git a/src/formaters.ts b/src/formaters.ts
index 8048d63..59129ba 100644
--- a/src/formaters.ts
+++ b/src/formaters.ts
@@ -11,7 +11,6 @@ export const percentFormater = new Intl.NumberFormat("en-US", {
     maximumFractionDigits: 0
 });
 
-
 const timeFormat = new Intl.NumberFormat("en-US", {
     minimumFractionDigits: 0,
     maximumFractionDigits: 0,
diff --git a/src/generated/mammon/api.ts b/src/generated/mammon/api.ts
index 3c379b5..30078db 100644
--- a/src/generated/mammon/api.ts
+++ b/src/generated/mammon/api.ts
@@ -83,8 +83,8 @@ export interface RuleBookResponse {
 }
 export interface RuleResponse {
     'rate': RuleResponseRateEnum;
-    'fromLedgerId': string;
-    'toLedgerId': string;
+    'fromLedgerId'?: string;
+    'toLedgerId'?: string;
 }
 
 export const RuleResponseRateEnum = {
@@ -736,7 +736,7 @@ export const RuleBookControllerApiAxiosParamCreator = function (configuration?:
         findByCharacterId: async (characterId: number, options: RawAxiosRequestConfig = {}): Promise<RequestArgs> => {
             // verify required parameter 'characterId' is not null or undefined
             assertParamExists('findByCharacterId', 'characterId', characterId)
-            const localVarPath = `/rule-books/{characterId}`
+            const localVarPath = `/characters/{characterId}/rule-book`
                 .replace('{characterId}', encodeURIComponent(String(characterId)));
             // use dummy base URL string because the URL constructor only accepts absolute URLs.
             const localVarUrlObj = new URL(localVarPath, DUMMY_BASE_URL);
diff --git a/src/ledger/CreateLedgerModal.vue b/src/ledger/CreateLedgerModal.vue
index 6508dd5..b11a9d2 100644
--- a/src/ledger/CreateLedgerModal.vue
+++ b/src/ledger/CreateLedgerModal.vue
@@ -6,6 +6,7 @@ import {isCombined, Ledger, LedgerType, LedgerTypes, useLedgersStore} from "./le
 import {Modal} from "@/components";
 import LedgerLabel from "./LedgerLabel.vue";
 import {PlusIcon, TrashIcon} from '@heroicons/vue/24/outline';
+import LedgerSelect from "@/ledger/LedgerSelect.vue";
 
 interface Props {
   ledgerId?: string;
@@ -119,9 +120,7 @@ defineExpose({ open });
           </div>
         </div>
         <div v-if="availableLedgers.length" class="flex">
-          <select v-model="selectedLedger" class="grow">
-            <option v-for="ledger in availableLedgers" :key="ledger.ledgerId" :value="ledger">{{ ledger.name }}</option>
-          </select>
+          <LedgerSelect v-model="selectedLedger" class="grow" :ledgers="availableLedgers" />
           <div class="flex justify-end me-4 ms-2">
             <button class="btn-icon" @click="addMember"><PlusIcon /></button>
           </div>
diff --git a/src/ledger/LedgerSelect.vue b/src/ledger/LedgerSelect.vue
new file mode 100644
index 0000000..ef81af3
--- /dev/null
+++ b/src/ledger/LedgerSelect.vue
@@ -0,0 +1,22 @@
+<script setup lang="ts">
+import {Ledger, useLedgersStore} from "@/ledger/ledger.ts";
+import {storeToRefs} from "pinia";
+import {computed} from "vue";
+
+interface Props {
+  ledgers?: Ledger[];
+}
+
+const props = defineProps<Props>()
+const ledger = defineModel<Ledger>();
+const {ledgers: allLedgers} = storeToRefs(useLedgersStore());
+
+const ledgersToUse = computed(() => props.ledgers || allLedgers);
+
+</script>
+
+<template>
+  <select v-model="ledger">
+    <option v-for="ledger in ledgersToUse" :key="ledger.ledgerId" :value="ledger">{{ ledger.name }}</option>
+  </select>
+</template>
\ No newline at end of file
diff --git a/src/ledger/index.ts b/src/ledger/index.ts
index c808622..10638d5 100644
--- a/src/ledger/index.ts
+++ b/src/ledger/index.ts
@@ -1,4 +1,5 @@
 export * from './ledger';
 
 export {default as LedgerLabel} from './LedgerLabel.vue';
+export {default as LedgerSelect} from './LedgerSelect.vue';
 export {default as CreateLedgerModal} from './CreateLedgerModal.vue';
\ No newline at end of file
diff --git a/src/mammon/mammonService.ts b/src/mammon/mammonService.ts
index ba051b1..8f527fc 100644
--- a/src/mammon/mammonService.ts
+++ b/src/mammon/mammonService.ts
@@ -1,6 +1,6 @@
 import {logResource} from "@/service";
 import axios from "axios";
-import {CharacterControllerApi, LedgerControllerApi} from "@/generated/mammon";
+import {CharacterControllerApi, LedgerControllerApi, RuleBookControllerApi} from "@/generated/mammon";
 
 export const mammonUrl = import.meta.env.VITE_MAMMON_URL;
 export const mammonAddCharacterUrl = mammonUrl + "oauth2/authorization/esi"
@@ -16,3 +16,4 @@ logResource(mammonAxiosInstance)
 
 export const ledgerControllerApi = new LedgerControllerApi(undefined, mammonUrl, mammonAxiosInstance);
 export const characterControllerApi = new CharacterControllerApi(undefined, mammonUrl, mammonAxiosInstance);
+export const ruleBookControllerApi = new RuleBookControllerApi(undefined, mammonUrl, mammonAxiosInstance);
diff --git a/src/pages/rules/EditRuleBook.vue b/src/pages/rules/EditRuleBook.vue
index b30b06f..8c47c93 100644
--- a/src/pages/rules/EditRuleBook.vue
+++ b/src/pages/rules/EditRuleBook.vue
@@ -1,18 +1,28 @@
 <script setup lang="ts">
 import {Character, CharacterLabel, useCharactersStore} from "@/characters";
 import {useRoute} from "vue-router";
-import {ref, watch} from "vue";
+import {ref, watch, watchEffect} from "vue";
 import log from "loglevel";
+import {activityTypes, findByCharacterId, RuleBook, RuleSetInput} from "@/rules";
 
-const {findById} = useCharactersStore();
-
+const {findById: findCharacterById} = useCharactersStore();
 const character = ref<Character>();
 
+const ruleBook = ref<RuleBook>();
+
+watchEffect(async () => {
+  const characterId = character.value?.characterId;
+
+  if (characterId) {
+    ruleBook.value = await findByCharacterId(characterId);
+  }
+});
+
 watch(useRoute(), async route => {
   if (route.params.characterId) {
     const id = parseInt(typeof route.params.characterId === 'string' ? route.params.characterId : route.params.characterId[0]);
 
-    character.value = findById(id);
+    character.value = await findCharacterById(id);
     log.info('Loaded character:', character.value);
   } else {
     character.value = undefined;
@@ -23,8 +33,14 @@ watch(useRoute(), async route => {
 
 <template>
   <div v-if="character" class="grid mb-2 mt-4">
-    <div class="mb-4 border-b-1 flex">
-      <CharacterLabel class="flex grow mb-2" :character="character" size="128" />
+    <div class="mb-2 border-b-1 flex">
+      <CharacterLabel class="flex grow mb-2" :character="character" :size="64" />
+    </div>
+    <div v-if="ruleBook" class="flex-col">
+      <div class="flex-col grow border-b-1" v-for="activityType in activityTypes" :key="activityType">
+        <span>{{ activityType }}</span>
+        <RuleSetInput v-model="ruleBook.ruleSets[activityType]" />
+      </div>
     </div>
   </div>
 </template>
\ No newline at end of file
diff --git a/src/routes.ts b/src/routes.ts
index bf20236..67a0e7d 100644
--- a/src/routes.ts
+++ b/src/routes.ts
@@ -10,7 +10,7 @@ export const routes: RouteRecordRaw[] = [
 
     {path: '/rules', component: () => import('@/pages/Rules.vue'), children: [
         {path: '', component: () => import('./pages/rules/ListRuleBooks.vue')},
-        {path: ':characterId', name: 'character-rulebook', component: () => import('@/pages/rules/EditRuleBook.vue')},
+        {path: '/characters/:characterId/rule-book', name: 'character-rulebook', component: () => import('@/pages/rules/EditRuleBook.vue')},
     ]},
 
     {path: '/market', component: () => import('@/pages/Market.vue'), children: [
diff --git a/src/rules/RuleInput.vue b/src/rules/RuleInput.vue
new file mode 100644
index 0000000..a783eaf
--- /dev/null
+++ b/src/rules/RuleInput.vue
@@ -0,0 +1,37 @@
+<script setup lang="ts">
+
+import {RuleResponse, RuleResponseRateEnum} from "@/generated/mammon";
+import {computed} from "vue";
+import {isMain, Ledger, LedgerSelect, useLedgersStore} from "@/ledger";
+
+const rule = defineModel<RuleResponse>();
+
+const ledgersStore = useLedgersStore();
+const {findById} = ledgersStore;
+const ledgers = computed(() => ledgersStore.ledgers.filter(isMain));
+
+const ledgerComputed = (key: 'fromLedgerId' | 'toLedgerId') => computed<Ledger | undefined>({
+  get: () => rule.value && rule.value[key] ? findById(rule.value[key]) : undefined,
+  set: value => {
+    if (value) {
+      rule.value = {...rule.value, [key]: value.ledgerId}
+    }
+  }
+})
+
+const fromLedger = ledgerComputed('fromLedgerId')
+const toLedger = ledgerComputed('toLedgerId')
+
+</script>
+
+<template>
+  <select class="me-2 grow" v-model="rule.rate">
+    <option v-for="rateType in RuleResponseRateEnum" :key="rateType" :value="rateType">{{ rateType }}</option>
+  </select>
+ <LedgerSelect class="me-2 grow" v-model="fromLedger" :ledgers="ledgers" />
+ <LedgerSelect class="me-2 grow" v-model="toLedger" :ledgers="ledgers" />
+</template>
+
+<style scoped>
+
+</style>
\ No newline at end of file
diff --git a/src/rules/RuleSetInput.vue b/src/rules/RuleSetInput.vue
new file mode 100644
index 0000000..d12b546
--- /dev/null
+++ b/src/rules/RuleSetInput.vue
@@ -0,0 +1,40 @@
+<script setup lang="ts">
+
+import {RuleResponse, RuleResponseRateEnum, RuleSetResponse} from "@/generated/mammon";
+import RuleInput from "@/rules/RuleInput.vue";
+import {computed} from "vue";
+import {PlusIcon, TrashIcon} from '@heroicons/vue/24/outline';
+
+const ruleSet = defineModel<RuleSetResponse>();
+const rules = computed<RuleResponse[]>({
+  get: () =>  ruleSet.value && ruleSet.value.rules ? ruleSet.value.rules : [],
+  set: value => ruleSet.value = {rules: value}
+})
+
+const addRule = () => {
+  rules.value = [...rules.value, {rate: RuleResponseRateEnum.None}]
+}
+
+const setRule = (index: number, rule?: RuleResponse) => {
+  if (!rule) {
+    return;
+  }
+  rules.value = rules.value.with(index, rule)
+}
+
+const removeRule = (index: number) => {
+  rules.value = rules.value.toSpliced(index, 1)
+}
+</script>
+
+<template>
+<div class="flex-col">
+  <div class="flex items-end gap-2 mt-2" v-for="(rule, index) in rules" :key="index">
+    <RuleInput :modelValue="rule" @update:modelValue="v => setRule(index, v)" />
+    <button class="btn-icon" @click="removeRule(index)"><TrashIcon /></button>
+  </div>
+  <div class="flex justify-end mb-2 mt-2">
+    <button class="btn-icon" @click="addRule"><PlusIcon /></button>
+  </div>
+</div>
+</template>
diff --git a/src/rules/index.ts b/src/rules/index.ts
index e69de29..7139a2f 100644
--- a/src/rules/index.ts
+++ b/src/rules/index.ts
@@ -0,0 +1,3 @@
+export * from "./rules";
+
+export {default as RuleSetInput} from './RuleSetInput.vue';
\ No newline at end of file
diff --git a/src/rules/rules.ts b/src/rules/rules.ts
new file mode 100644
index 0000000..a92d1c4
--- /dev/null
+++ b/src/rules/rules.ts
@@ -0,0 +1,16 @@
+import {ruleBookControllerApi} from "@/mammon";
+import {RuleBookResponse, RuleSetResponse} from "@/generated/mammon";
+
+export const activityTypes = {
+    itemBought: "ITEM_BOUGHT",
+    itemSold: "ITEM_SOLD",
+    bountyEarned: "BOUNTY_EARNED",
+    itemManufactured: "ITEM_MANUFACTURED"
+} as const;
+
+export type ActivityType = typeof activityTypes[keyof typeof activityTypes];
+export type RuleBook = RuleBookResponse & { ruleSets: { [key: ActivityType]: RuleSetResponse; } }
+
+export const findByCharacterId = (characterId: number): Promise<RuleBook> => ruleBookControllerApi.findByCharacterId(characterId)
+    .then(response => response.data)
+    .catch(() => ({characterId, ruleSets: {}}));
\ No newline at end of file
diff --git a/src/utils.ts b/src/utils.ts
index e99fc39..d1d6dd7 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1 +1 @@
-export const copyToClipboard = (s: string) => navigator.clipboard.writeText(s);
\ No newline at end of file
+export const copyToClipboard = (s: string) => navigator.clipboard.writeText(s);