diff --git a/flake.nix b/flake.nix
index b02dd6b..c02d699 100644
--- a/flake.nix
+++ b/flake.nix
@@ -39,7 +39,8 @@
                          rustfmt
                          pre-commit
                          rustPackages.clippy
-                         cargo-tarpaulin];
+                         cargo-tarpaulin
+                         deno];
           RUST_SRC_PATH = rustPlatform.rustLibSrc;
         };
       });
diff --git a/migrations/avro/events.ts b/migrations/avro/events.ts
new file mode 100644
index 0000000..bddb894
--- /dev/null
+++ b/migrations/avro/events.ts
@@ -0,0 +1,125 @@
+import {Command} from "https://deno.land/x/cliffy@v0.25.7/command/mod.ts";
+import {concat, partial} from 'https://deno.land/x/lodash@4.17.15-es/lodash.js';
+import {join, dirname} from "https://deno.land/std@0.171.0/path/mod.ts";
+
+
+enum AvroPrimitives {
+  Null = "null",
+  Boolean = "boolean",
+  Int = "int",
+  Long = "long",
+  Float = "float",
+  Double = "double",
+  Bytes = "bytes",
+  String = "string"
+}
+
+interface AvroRecordField {
+  name: string,
+  doc?: string,
+  default?: any,
+  type: AvroTypes,
+}
+
+interface AvroRecord {
+  name: string,
+  type: "record",
+  namespace?: string,
+  doc?: string,
+  aliases?: string[]
+  fields: AvroRecordField[]
+}
+
+interface AvroEnum {
+  name: string,
+  namespace?: string,
+  aliases?: string[],
+  type: "enum",
+  symbols: string[],
+}
+
+type AvroUnion = AvroTypes[];
+
+type AvroTypes = AvroPrimitives | AvroRecord | AvroUnion | AvroEnum;
+
+const CacheChequeEvent: AvroRecord = {
+  name: "event",
+  type: "record",
+  fields: [
+    {name: "account", type: AvroPrimitives.Long},
+  ]
+}
+
+const BogusEvent: AvroRecord = {
+  name: "bogus",
+  type: "record",
+  fields: [
+    {name: "account", type: AvroPrimitives.Long},
+    {name: "foo", type: AvroPrimitives.Long},
+  ]
+}
+
+const allEvents: AvroRecord[] = [CacheChequeEvent, BogusEvent]
+
+const eventTypes: AvroEnum = {
+  type: "enum",
+  name: "EventType",
+  symbols: allEvents.map(x => x.name),
+}
+
+const LedgerEventsSchema: AvroRecord = {
+  name: "LedgerEvent",
+  type: "record",
+  fields: [
+    {name: "event_type", type: eventTypes},
+    {name: "event", type: allEvents},
+  ]
+};
+
+interface CliOptions {
+  dry: boolean,
+  output: string,
+}
+
+type Serializer = (rec: AvroRecord) => Promise<void>;
+
+function getOutputFileName(outputDir: string, rec: AvroRecord): string {
+  return join(outputDir, rec.name + '.json');
+}
+
+async function drySerializer(outputDir: string, rec: AvroRecord): Promise<void> {
+  console.log(getOutputFileName(outputDir, rec) + " : " + JSON.stringify(rec));
+}
+
+async function fileSerializer(outputDir: string, rec: AvroRecord): Promise<void> {
+  let outputFile = getOutputFileName(outputDir, rec);
+  await Deno.mkdir(dirname(outputFile), { recursive: true });
+  await Deno.writeTextFile(outputFile, JSON.stringify(rec, null, 4));
+
+}
+
+function getSerializer(dry: boolean, outputDir: string): Serializer {
+  return dry ? partial(drySerializer, outputDir) : partial(fileSerializer, outputDir);
+}
+
+
+async function main(options: CliOptions): Promise<void> {
+  let serializer = getSerializer(options.dry, options.output);
+  for(let e of concat([], allEvents, LedgerEventsSchema)){
+   await serializer(e);
+  }
+}
+
+
+await new Command()
+.name("ledger-avro-schemata-builder")
+.version("0.1.0")
+.description("Build avro schemata for ledger.")
+.option("--dry [value:boolean]", "Do not output any files", {
+  default: false,
+})
+.option("--output [value:file]", "directory to output schemata", {
+  default: '.',
+})
+.action(main)
+.parse(Deno.args);