diff --git a/README.md b/README.md
index a83e650..e472471 100644
--- a/README.md
+++ b/README.md
@@ -148,6 +148,7 @@ to get a new pair of tokens.
 fairpost: help
 fairpost: @userid get-user
 fairpost: @userid get-feed
+fairpost: @userid get-fields --model=user|feed|platform|source|post [--platform=xxx]
 fairpost: @userid get-platform --platform=xxx
 fairpost: @userid put-platform --platform=xxx << payload
 fairpost: @userid edit-platform --platform=xxx (cli only)
diff --git a/src/cli.ts b/src/cli.ts
index 3a0a3d3..742d8d8 100644
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -29,6 +29,7 @@ const COMMAND = process.argv[2]?.includes("@")
 const DRY_RUN = !!getOption("dry-run");
 const OPERATOR = (getOption("operator") as string) ?? "admin";
 const PASSWORD = (getOption("password") as string) ?? undefined;
+const MODEL = (getOption("model") as string) ?? undefined;
 const PLATFORMS =
   ((getOption("platforms") as string)?.split(",") as PlatformId[]) ?? undefined;
 const SOURCES = (getOption("sources") as string)?.split(",") ?? undefined;
@@ -94,6 +95,7 @@ async function execute(command: string): Promise<string> {
       dryrun: DRY_RUN,
       user: USER,
       password: PASSWORD,
+      model: MODEL,
       platforms: PLATFORMS,
       platform: PLATFORM,
       sources: SOURCES,
diff --git a/src/mappers/FeedMapper.ts b/src/mappers/FeedMapper.ts
index 0aaf114..2a4be5c 100644
--- a/src/mappers/FeedMapper.ts
+++ b/src/mappers/FeedMapper.ts
@@ -5,7 +5,7 @@ import Feed from "../models/Feed.ts";
 
 export default class FeedMapper extends AbstractMapper<FeedDto> {
   private feed: Feed;
-  mapping: FieldMapping = {
+  static feedMapping: FieldMapping = {
     model: {
       type: "string",
       label: "Model",
@@ -38,6 +38,7 @@ export default class FeedMapper extends AbstractMapper<FeedDto> {
       required: false,
     },
   };
+  mapping = FeedMapper.feedMapping;
 
   constructor(feed: Feed) {
     super(feed.user);
diff --git a/src/mappers/PlatformMapper.ts b/src/mappers/PlatformMapper.ts
index a55ab62..58a9ec3 100644
--- a/src/mappers/PlatformMapper.ts
+++ b/src/mappers/PlatformMapper.ts
@@ -5,7 +5,7 @@ import Platform from "../models/Platform.ts";
 
 export default class PlatformMapper extends AbstractMapper<PlatformDto> {
   private platform: Platform;
-  mapping: FieldMapping = {
+  private static platformMapping: FieldMapping = {
     model: {
       type: "string",
       label: "Model",
@@ -31,9 +31,11 @@ export default class PlatformMapper extends AbstractMapper<PlatformDto> {
       set: ["managePlatforms"],
     },
     // more fields from platform.settings
-    // added in constructor
+    // added in mapper constructor
   };
 
+  mapping = structuredClone(PlatformMapper.platformMapping);
+
   constructor(platform: Platform) {
     super(platform.user);
     this.platform = platform;
diff --git a/src/mappers/PostMapper.ts b/src/mappers/PostMapper.ts
index b1128eb..ab4d0c6 100644
--- a/src/mappers/PostMapper.ts
+++ b/src/mappers/PostMapper.ts
@@ -1,11 +1,11 @@
 import AbstractMapper from "./AbstractMapper.ts";
-import { PostDto, FieldMapping, FileInfo } from "../types/index.ts";
+import { PostDto, FileInfo, FieldMapping } from "../types/index.ts";
 import Operator from "../models/Operator.ts";
 import Post from "../models/Post.ts";
 
 export default class PostMapper extends AbstractMapper<PostDto> {
   private post: Post;
-  mapping: FieldMapping = {
+  static postMapping: FieldMapping = {
     model: {
       type: "string",
       label: "Model",
@@ -121,6 +121,7 @@ export default class PostMapper extends AbstractMapper<PostDto> {
       set: ["none"],
     },
   };
+  mapping = PostMapper.postMapping;
 
   constructor(post: Post) {
     super(post.platform.user);
diff --git a/src/mappers/SourceMapper.ts b/src/mappers/SourceMapper.ts
index 7c3a758..62a3604 100644
--- a/src/mappers/SourceMapper.ts
+++ b/src/mappers/SourceMapper.ts
@@ -1,11 +1,11 @@
 import AbstractMapper from "./AbstractMapper.ts";
-import { SourceDto, FieldMapping, FileInfo } from "../types/index.ts";
+import { SourceDto, FileInfo, FieldMapping } from "../types/index.ts";
 import Operator from "../models/Operator.ts";
 import Source from "../models/Source.ts";
 
 export default class SourceMapper extends AbstractMapper<SourceDto> {
   private source: Source;
-  mapping: FieldMapping = {
+  static sourceMapping: FieldMapping = {
     model: {
       type: "string",
       label: "Model",
@@ -49,6 +49,7 @@ export default class SourceMapper extends AbstractMapper<SourceDto> {
       set: ["manageSources"],
     },
   };
+  mapping = SourceMapper.sourceMapping;
 
   constructor(source: Source) {
     super(source.feed.user);
diff --git a/src/mappers/UserMapper.ts b/src/mappers/UserMapper.ts
index 57baa1e..3599039 100644
--- a/src/mappers/UserMapper.ts
+++ b/src/mappers/UserMapper.ts
@@ -3,7 +3,7 @@ import { UserDto, FieldMapping } from "../types/index.ts";
 import Operator from "../models/Operator.ts";
 
 export default class UserMapper extends AbstractMapper<UserDto> {
-  mapping: FieldMapping = {
+  static userMapping: FieldMapping = {
     model: {
       type: "string",
       label: "Model",
@@ -39,6 +39,7 @@ export default class UserMapper extends AbstractMapper<UserDto> {
       required: false,
     },
   };
+  mapping = UserMapper.userMapping;
 
   /**
    * Return a dto based on the operator and operation
diff --git a/src/models/Operator.ts b/src/models/Operator.ts
index b06db67..83af827 100644
--- a/src/models/Operator.ts
+++ b/src/models/Operator.ts
@@ -1,4 +1,10 @@
 import User from "./User.ts";
+import { FieldMapping, ProcessedFieldMapping } from "../types/index.ts";
+import Platform from "../models/Platform.ts";
+import UserMapper from "../mappers/UserMapper.ts";
+import FeedMapper from "../mappers/FeedMapper.ts";
+import SourceMapper from "../mappers/SourceMapper.ts";
+import PostMapper from "../mappers/PostMapper.ts";
 
 /**
  * Operator - represents the user executing an operation or command.
@@ -79,4 +85,67 @@ export default class Operator {
     //user?.log.info(permissions);
     return permissions;
   }
+
+  public getFieldMapping(
+    user: User,
+    model: string,
+    instance?: object,
+  ): ProcessedFieldMapping {
+    let rawFieldMapping: FieldMapping | undefined = undefined;
+    let processedFieldMapping: ProcessedFieldMapping = {};
+    switch (model) {
+      case "user":
+        rawFieldMapping = UserMapper.userMapping;
+        break;
+
+      case "feed":
+        rawFieldMapping = FeedMapper.feedMapping;
+        break;
+
+      case "source":
+        rawFieldMapping = SourceMapper.sourceMapping;
+        break;
+
+      case "platform":
+        if (!instance || !(instance instanceof Platform)) {
+          throw user.log.error(
+            "Operator.getFieldMapping",
+            "Platform is required",
+          );
+        }
+        const platform = instance as Platform;
+        rawFieldMapping = platform.mapper.mapping;
+        break;
+
+      case "post":
+        rawFieldMapping = PostMapper.postMapping;
+        break;
+    }
+    if (!rawFieldMapping) {
+      throw user.log.error("Operator.getFieldMapping: no such mapping", model);
+    }
+    const permissions = this.getPermissions(user);
+    for (const fieldName of Object.keys(rawFieldMapping)) {
+      const rawField = rawFieldMapping[fieldName];
+      const processedField = { ...rawField, get: true, set: true };
+      for (const operation of ["get", "set"] as const) {
+        if (rawField[operation].includes("any"))
+          processedField[operation] = true;
+        else if (rawField[operation].includes("none"))
+          processedField[operation] = false;
+        else if (
+          rawField[operation].some(
+            (permission) =>
+              permission in permissions &&
+              permissions[permission as keyof typeof permissions],
+          )
+        )
+          processedField[operation] = true;
+      }
+      if (processedField["get"]) {
+        processedFieldMapping[fieldName] = processedField;
+      }
+    }
+    return processedFieldMapping;
+  }
 }
diff --git a/src/models/Platform.ts b/src/models/Platform.ts
index 895eebd..0128560 100644
--- a/src/models/Platform.ts
+++ b/src/models/Platform.ts
@@ -23,7 +23,7 @@ export default class Platform {
   defaultBody: string = "Fairpost feed";
   assetsFolder: string = "_fairpost";
   postFileName: string = "post.json";
-  mapper: PlatformMapper;
+  mapper!: PlatformMapper; // child *must* set this
   settings: FieldMapping = {};
   interval: number;
   constructor(user: User) {
@@ -32,7 +32,6 @@ export default class Platform {
     this.interval = Number(
       this.user.data.get("settings", "FEED_INTERVAL", "7"),
     );
-    this.mapper = new PlatformMapper(this);
   }
 
   /**
diff --git a/src/services/Fairpost.ts b/src/services/Fairpost.ts
index 7b0a237..86c50f8 100644
--- a/src/services/Fairpost.ts
+++ b/src/services/Fairpost.ts
@@ -1,7 +1,11 @@
 import log4js from "log4js";
 import log4jsConfig from "../config/log4js.json" with { type: "json" };
 
-import { CommandArguments, CombinedResult } from "../types/index.ts";
+import {
+  CommandArguments,
+  CombinedResult,
+  ProcessedFieldMapping,
+} from "../types/index.ts";
 import { PlatformId } from "../platforms/index.ts";
 import {
   FeedDto,
@@ -20,6 +24,7 @@ import Operator from "../models/Operator.ts";
 import User from "../models/User.ts";
 
 type FairpostOutput =
+  | ProcessedFieldMapping
   | FeedDto
   | PlatformDto
   | PostDto
@@ -188,6 +193,34 @@ class Fairpost {
         }
         */
 
+        case "get-fields": {
+          if (!permissions.manageAccount) {
+            throw new Error("Missing permissions for command " + command);
+          }
+          if (!user) {
+            throw new Error("user is required for command " + command);
+          }
+          if (!args.model) {
+            throw user.log.error(
+              "CommandHandler " + command,
+              "Missing argument: model",
+            );
+          }
+          let instance: object | undefined = undefined;
+          if (args.model === "platform") {
+            if (!args.platform) {
+              throw user.log.error(
+                "CommandHandler " + command,
+                "Missing argument: platform",
+              );
+            }
+            instance = user.getPlatform(args.platform);
+          }
+
+          output = operator.getFieldMapping(user, args.model, instance);
+          break;
+        }
+
         case "refresh-token": {
           if (!permissions.manageAccount) {
             throw new Error("Missing permissions for command " + command);
@@ -972,6 +1005,7 @@ class Fairpost {
               `${cmd} help`,
               `${cmd} @userid get-user`,
               `${cmd} @userid get-feed`,
+              `${cmd} @userid get-fields --model=user|feed|platform|source|post [--platform=xxx]`,
               `${cmd} @userid get-platform --platform=xxx`,
               `${cmd} @userid put-platform --platform=xxx << payload`,
               `${cmd} @userid edit-platform --platform=xxx (cli only)`,
diff --git a/src/services/Server.ts b/src/services/Server.ts
index ffdc95d..00224e5 100644
--- a/src/services/Server.ts
+++ b/src/services/Server.ts
@@ -80,6 +80,7 @@ export default class Server {
 
     // read other params from query
     const password = parsed.searchParams.get("password") || undefined;
+    const model = parsed.searchParams.get("model") || undefined;
     const dryrun = parsed.searchParams.get("dry-run") === "true";
     const date = parsed.searchParams.get("date");
     const post = parsed.searchParams.get("post");
@@ -112,6 +113,7 @@ export default class Server {
     const args = {
       password: password,
       dryrun: dryrun || undefined,
+      model: model,
       platforms: platforms,
       platform: platform,
       sources: sources,
diff --git a/src/types/CommandArguments.ts b/src/types/CommandArguments.ts
index 5a0d85a..011d040 100644
--- a/src/types/CommandArguments.ts
+++ b/src/types/CommandArguments.ts
@@ -9,6 +9,7 @@ export default interface CommandArguments {
   dryrun?: boolean;
   user?: string;
   password?: string;
+  model?: string;
   platforms?: PlatformId[];
   platform?: PlatformId;
   sources?: string[];
diff --git a/src/types/FieldMapping.ts b/src/types/FieldMapping.ts
index 566c8d8..c4c53e1 100644
--- a/src/types/FieldMapping.ts
+++ b/src/types/FieldMapping.ts
@@ -22,3 +22,12 @@ export default interface FieldMapping {
     default?: string | string[] | number | boolean | Date | object;
   };
 }
+
+// after applying operator and user, get and set
+// can be represented by simple booleans:
+export interface ProcessedFieldMapping {
+  [field: string]: Omit<FieldMapping[string], "get" | "set"> & {
+    get: boolean;
+    set: boolean;
+  };
+}
diff --git a/src/types/index.ts b/src/types/index.ts
index 6e707b9..71e8bad 100644
--- a/src/types/index.ts
+++ b/src/types/index.ts
@@ -1,6 +1,7 @@
 export type { default as CommandArguments } from "./CommandArguments.ts";
 export type { default as CombinedResult } from "./CombinedResult.ts";
 export type { default as FieldMapping } from "./FieldMapping.ts";
+export type { ProcessedFieldMapping } from "./FieldMapping.ts";
 export type { default as Dto } from "./Dto.ts";
 export type { default as FeedDto } from "./FeedDto.ts";
 export { default as FileGroup } from "./FileGroup.ts";