diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..deb6b0a
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+.yarn/install-state.gz
diff --git a/.yarn/install-state.gz b/.yarn/install-state.gz
index 6af1922..8c51572 100644
Binary files a/.yarn/install-state.gz and b/.yarn/install-state.gz differ
diff --git a/package.json b/package.json
index dcf7c20..908a5fe 100644
--- a/package.json
+++ b/package.json
@@ -16,9 +16,11 @@
     "typecheck": "yarn generate && tsc --noEmit"
   },
   "dependencies": {
+    "@automerge/automerge": "^3.3.0",
     "@bufbuild/protobuf": "^2.12.1",
     "@connectrpc/connect": "^2.1.2",
-    "@connectrpc/connect-node": "^2.1.2"
+    "@connectrpc/connect-node": "^2.1.2",
+    "@quixos/camino-datatypes": "https://gitea-external.egads.tutti.syntaxblitz.net/quixos/camino-datatypes.git#commit=fa50782559944b88c410e264acadf79266b70b43"
   },
   "devDependencies": {
     "@bufbuild/protoc-gen-es": "^2.12.1",
diff --git a/src/index.ts b/src/index.ts
index 588fb5f..a5f644f 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -8,6 +8,12 @@ import {
   type HandlerContext,
   type Interceptor,
 } from "@connectrpc/connect";
+import * as Automerge from "@automerge/automerge";
+import {
+  encodeAutomergeFieldWrite,
+  loadAutomergeFieldDoc,
+  type CaminoAutomergeDoc,
+} from "@quixos/camino-datatypes/crdt-automerge";
 import {
   connectNodeAdapter,
   createConnectTransport,
@@ -183,6 +189,11 @@ export type Field<T> = {
   set(value: T): Promise<void>;
 };
 
+export type CrdtField<T> = Field<CaminoAutomergeDoc<T>> & {
+  change(fn: (doc: { value: T }) => void): Promise<CaminoAutomergeDoc<T>>;
+  replaceFromJson(value: T): Promise<void>;
+};
+
 export type LiveFieldValue<T> = {
   $caminoValue: T;
   $caminoSource: {
@@ -475,6 +486,11 @@ const bytesToBase64 = (value: Uint8Array) =>
 
 const base64ToBytes = (value: string) => Buffer.from(value, "base64");
 
+type FieldCodec = {
+  fieldType?: string;
+  conflictStrategy?: string;
+};
+
 const sourceToProto = (value: unknown) => {
   if (!isRecord(value) || !isRecord(value.field)) {
     return undefined;
@@ -507,12 +523,30 @@ const sourceToProto = (value: unknown) => {
   });
 };
 
+const codecFromSource = (value: unknown): FieldCodec | undefined => {
+  if (!isRecord(value) || !isRecord(value.field)) {
+    return undefined;
+  }
+  const field = value.field;
+  return {
+    ...(typeof field.fieldType === "string" ? { fieldType: field.fieldType } : {}),
+    ...(typeof field.conflictStrategy === "string"
+      ? { conflictStrategy: field.conflictStrategy }
+      : {}),
+  };
+};
+
 const withSource = (value: Value, source: unknown): Value => {
   const sourceValue = sourceToProto(source);
   return sourceValue ? create(ValueSchema, { ...value, source: sourceValue }) : value;
 };
 
-export const jsToProtoValue = (value: unknown): Value => {
+export const jsToProtoValue = (value: unknown, codec?: FieldCodec): Value => {
+  if (codec?.conflictStrategy === "crdt" && codec.fieldType) {
+    return jsToProtoValue(
+      encodeAutomergeFieldWrite(value, codec.fieldType),
+    );
+  }
   if (value === null || value === undefined) {
     return create(ValueSchema, {
       kind: {
@@ -551,14 +585,17 @@ export const jsToProtoValue = (value: unknown): Value => {
       kind: {
         case: "listValue",
         value: create(ListValueSchema, {
-          values: value.map(jsToProtoValue),
+          values: value.map((entry) => jsToProtoValue(entry)),
         }),
       },
     });
   }
   if (isRecord(value)) {
     if (Object.hasOwn(value, "$caminoValue") && isRecord(value.$caminoSource)) {
-      return withSource(jsToProtoValue(value.$caminoValue), value.$caminoSource);
+      return withSource(
+        jsToProtoValue(value.$caminoValue, codecFromSource(value.$caminoSource)),
+        value.$caminoSource,
+      );
     }
     if (typeof value.$caminoRef === "string") {
       return create(ValueSchema, {
@@ -631,11 +668,12 @@ export const protoValueToJs = (value: Value | undefined): unknown => {
     case "refValue":
       return value.kind.value.objectId;
     case "crdtValue":
-      return {
+      return loadAutomergeFieldDoc({
         $caminoCrdtType: value.kind.value.type,
-        $caminoCrdtEncoding: value.kind.value.encoding,
+        $caminoCrdtEncoding:
+          value.kind.value.encoding === "base64" ? "base64" : "base64",
         $caminoCrdtPayload: bytesToBase64(value.kind.value.payload),
-      };
+      }, value.kind.value.type);
   }
 };
 
@@ -761,6 +799,7 @@ export const createField = <T>(
   camino: CaminoClient,
   objectId: string,
   fieldName: string,
+  codec?: FieldCodec,
 ): Field<T> => ({
   async get() {
     recordDerivedDependency({ kind: "field", objectId, fieldName });
@@ -771,11 +810,44 @@ export const createField = <T>(
     await camino.setField({
       objectId,
       fieldName,
-      value: jsToProtoValue(value),
+      value: jsToProtoValue(value, codec),
     });
   },
 });
 
+export const createCrdtField = <T>(
+  camino: CaminoClient,
+  objectId: string,
+  fieldName: string,
+  fieldType: string,
+): CrdtField<T> => {
+  const field = createField<CaminoAutomergeDoc<T>>(camino, objectId, fieldName, {
+    fieldType,
+    conflictStrategy: "crdt",
+  });
+  return {
+    ...field,
+    async change(fn) {
+      const current = await field.get();
+      if (!current) {
+        throw new Error(`Cannot change missing CRDT field ${fieldName}`);
+      }
+      const next = Automerge.change(current, (doc) => {
+        fn(doc as { value: T });
+      }) as CaminoAutomergeDoc<T>;
+      await field.set(next);
+      return next;
+    },
+    async replaceFromJson(value) {
+      await camino.setField({
+        objectId,
+        fieldName,
+        value: jsToProtoValue(value, { fieldType, conflictStrategy: "crdt" }),
+      });
+    },
+  };
+};
+
 const createDependencyTrackingCaminoClient = (
   camino: CaminoClient,
 ): CaminoClient =>
diff --git a/yarn-project.nix b/yarn-project.nix
index f09f13d..ec9f010 100644
--- a/yarn-project.nix
+++ b/yarn-project.nix
@@ -156,11 +156,13 @@ let
   overriddenProject = optionalOverride overrideAttrs project;
 
 cacheEntries = {
+"@automerge/automerge@npm:3.3.0" = { filename = "@automerge-automerge-npm-3.3.0-3f6661ca17-74b3a8ef9e.zip"; hash = "sha512-dLOo7548v0B2DomHJ+za1RKOUv0rBTgJRUrnsrhbTsZHw8uipjXNv4MfIxVzGtQl2jenhLeb8TvIbsKKfpKv8g=="; };
 "@bufbuild/protobuf@npm:2.12.1" = { filename = "@bufbuild-protobuf-npm-2.12.1-d8afb467b3-2d40cfe4ec.zip"; hash = "sha512-LUDP5Ow7sOPwarLih3HcXcVm6qywVfvok9dWIbBAfQJy1I9ApJCtR97YOe1UFRThr3G7E68CSzrjbvDFbVbdqQ=="; };
 "@bufbuild/protoc-gen-es@npm:2.12.1" = { filename = "@bufbuild-protoc-gen-es-npm-2.12.1-6e9387fcb8-0e2805376d.zip"; hash = "sha512-DigFN22Lmj/OD9OdkPZa4dH/vqMSvi2tk2f3xyEqvFHcKleC531iqPhh7De9xtG9MM+sVRDRJCeCzXA/kH4f9Q=="; };
 "@bufbuild/protoplugin@npm:2.12.1" = { filename = "@bufbuild-protoplugin-npm-2.12.1-e1aebb80bf-c7b401ab31.zip"; hash = "sha512-x7QBqzHZSsaCXLm75c/3XQXSjuINRnskt6XUKZuaygZmhuo5t6OoRTuLWgGD+qd4HoP8LliAZhgHudMVX3Hr6Q=="; };
 "@connectrpc/connect-node@npm:2.1.2" = { filename = "@connectrpc-connect-node-npm-2.1.2-021434d5d5-ba8b0c9384.zip"; hash = "sha512-uosMk4TDgps3eqeoJtwM1Qpgk1J9LscBRgSRKDYzbqlgSitazqQrEEd/i+RWnknd7WbKD8d/X1sCcDXgKeE+qQ=="; };
 "@connectrpc/connect@npm:2.1.2" = { filename = "@connectrpc-connect-npm-2.1.2-ab34825de3-4e15000890.zip"; hash = "sha512-ThUACJAjt1Lv1E+pQKWuHh+gDhvrxLoM7ScruTWSDYw7hbd0UOZErUQruMqaJ1sMFxNviWuo7/A2F4Ex2wHWFQ=="; };
+"@quixos/camino-datatypes@https://gitea-external.egads.tutti.syntaxblitz.net/quixos/camino-datatypes.git#commit=fa50782559944b88c410e264acadf79266b70b43" = { filename = "@quixos-camino-datatypes-https-08035afa77-0223fd49ac.zip"; hash = "sha512-AiP9SawAVbzD/srTymZRhXZH01djfCteKuHWkkk2wBr66OPF0AaUy3stZyxwEgJrRh18cFcpTc4zcjWsu7mGAg=="; };
 "@types/node@npm:24.13.3" = { filename = "@types-node-npm-24.13.3-b512a0bbeb-a5bc08f49b.zip"; hash = "sha512-pbwI9JuVgdzcqQ4CzXcZejx5mECAdmSULlzVFhpVPU0q6AZPfjKUQQ10jX0Ji1wYSL5/pQwG8pxBk6sWvk5Z6w=="; };
 "@typescript/vfs@npm:1.6.4" = { filename = "@typescript-vfs-npm-1.6.4-78935c9d3e-acb9de42f2.zip"; hash = "sha512-rLneQvI/2j9149eQC6EG7zI6L0588OSpTbtFfibTU8pjuzUZPtGjL8hzPzrlkJlhKykLBr1iIWlIYb65v7YvYg=="; };
 "debug@npm:4.4.3" = { filename = "debug-npm-4.4.3-0105c6123a-d79136ec6c.zip"; hash = "sha512-15E27GyD7L79D2pVk9pqnJHsTX3cS1TIg9bnHsmsy19noaXpbQCjKBlrW1yG02XpjYo6cIVqrxa057GYXmf1pg=="; };
diff --git a/yarn.lock b/yarn.lock
index 855060c..13bc8a7 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -5,6 +5,13 @@ __metadata:
   version: 9
   cacheKey: 10c0
 
+"@automerge/automerge@npm:^3.3.0":
+  version: 3.3.0
+  resolution: "@automerge/automerge@npm:3.3.0"
+  checksum: 10c0/74b3a8ef9e3cbf40760e898727ecdad5128e52fd2b053809454ae7b2b85b4ec647c3cba2a635cdbf831f2315731ad425da37a784b79bf13bc86ec28a7e92aff2
+  languageName: node
+  linkType: hard
+
 "@bufbuild/protobuf@npm:2.12.1, @bufbuild/protobuf@npm:^2.12.1":
   version: 2.12.1
   resolution: "@bufbuild/protobuf@npm:2.12.1"
@@ -59,14 +66,25 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@quixos/camino-datatypes@https://gitea-external.egads.tutti.syntaxblitz.net/quixos/camino-datatypes.git#commit=fa50782559944b88c410e264acadf79266b70b43":
+  version: 0.1.0
+  resolution: "@quixos/camino-datatypes@https://gitea-external.egads.tutti.syntaxblitz.net/quixos/camino-datatypes.git#commit=fa50782559944b88c410e264acadf79266b70b43"
+  dependencies:
+    "@automerge/automerge": "npm:^3.3.0"
+  checksum: 10c0/0223fd49ac0055bcc3fecad3ca6651857647d357637c2b5e2ae1d6924936c01afae8e3c5d00694cb7b2d672c7012026b461d7c7057294dce337235acbbb98602
+  languageName: node
+  linkType: hard
+
 "@quixos/camino-package-runtime@workspace:.":
   version: 0.0.0-use.local
   resolution: "@quixos/camino-package-runtime@workspace:."
   dependencies:
+    "@automerge/automerge": "npm:^3.3.0"
     "@bufbuild/protobuf": "npm:^2.12.1"
     "@bufbuild/protoc-gen-es": "npm:^2.12.1"
     "@connectrpc/connect": "npm:^2.1.2"
     "@connectrpc/connect-node": "npm:^2.1.2"
+    "@quixos/camino-datatypes": "https://gitea-external.egads.tutti.syntaxblitz.net/quixos/camino-datatypes.git#commit=fa50782559944b88c410e264acadf79266b70b43"
     "@types/node": "npm:^24"
     typescript: "npm:^5.9.3"
   languageName: unknown