diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
new file mode 100644
index 00000000..c5e498b5
--- /dev/null
+++ b/.github/copilot-instructions.md
@@ -0,0 +1,4 @@
+- Do not add trivial comments, usually do not add blank lines inside functions.
+- Use Angular style commits, e.g `feat: implemented xyz`.
+- Make sure tests (`yarn test`) pass.
+- In the end, make sure linter and formatter pass.
\ No newline at end of file
diff --git a/src/avro/types.ts b/src/avro/types.ts
new file mode 100644
index 00000000..96ff0a4c
--- /dev/null
+++ b/src/avro/types.ts
@@ -0,0 +1,195 @@
+/**
+ * Apache Avro schema type definitions based on Avro 1.12.0 specification.
+ * Specification: https://avro.apache.org/docs/1.12.0/specification/
+ */
+
+// Base schema interface with common properties
+export interface AvroBaseSchema {
+  /** The schema type */
+  type: string;
+  /** Optional documentation for the schema */
+  doc?: string;
+  /** Optional JSON object of string-valued properties */
+  [key: string]: any;
+}
+
+// Primitive type schemas
+export interface AvroNullSchema extends AvroBaseSchema {
+  type: 'null';
+}
+
+export interface AvroBooleanSchema extends AvroBaseSchema {
+  type: 'boolean';
+}
+
+export interface AvroIntSchema extends AvroBaseSchema {
+  type: 'int';
+}
+
+export interface AvroLongSchema extends AvroBaseSchema {
+  type: 'long';
+}
+
+export interface AvroFloatSchema extends AvroBaseSchema {
+  type: 'float';
+}
+
+export interface AvroDoubleSchema extends AvroBaseSchema {
+  type: 'double';
+}
+
+export interface AvroBytesSchema extends AvroBaseSchema {
+  type: 'bytes';
+}
+
+export interface AvroStringSchema extends AvroBaseSchema {
+  type: 'string';
+}
+
+// Complex type schemas
+
+export interface AvroRecordField {
+  /** Name of the field */
+  name: string;
+  /** Schema of the field */
+  type: AvroSchema;
+  /** Optional documentation for the field */
+  doc?: string;
+  /** Optional default value for the field */
+  default?: any;
+  /** Optional ordering for the field */
+  order?: 'ascending' | 'descending' | 'ignore';
+  /** Optional aliases for the field */
+  aliases?: string[];
+}
+
+export interface AvroRecordSchema extends AvroBaseSchema {
+  type: 'record';
+  /** Name of the record schema */
+  name: string;
+  /** Optional namespace for the record */
+  namespace?: string;
+  /** Array of field definitions */
+  fields: AvroRecordField[];
+  /** Optional aliases for the record */
+  aliases?: string[];
+}
+
+export interface AvroEnumSchema extends AvroBaseSchema {
+  type: 'enum';
+  /** Name of the enum schema */
+  name: string;
+  /** Optional namespace for the enum */
+  namespace?: string;
+  /** Array of symbols in the enum */
+  symbols: string[];
+  /** Optional default symbol */
+  default?: string;
+  /** Optional aliases for the enum */
+  aliases?: string[];
+}
+
+export interface AvroArraySchema extends AvroBaseSchema {
+  type: 'array';
+  /** Schema of the array items */
+  items: AvroSchema;
+}
+
+export interface AvroMapSchema extends AvroBaseSchema {
+  type: 'map';
+  /** Schema of the map values */
+  values: AvroSchema;
+}
+
+export interface AvroUnionSchema extends Array<AvroSchema> {
+  /** Union schemas are represented as JSON arrays */
+}
+
+export interface AvroFixedSchema extends AvroBaseSchema {
+  type: 'fixed';
+  /** Name of the fixed schema */
+  name: string;
+  /** Optional namespace for the fixed */
+  namespace?: string;
+  /** Size of the fixed-length data in bytes */
+  size: number;
+  /** Optional aliases for the fixed */
+  aliases?: string[];
+}
+
+// Union of all primitive schemas
+export type AvroPrimitiveSchema =
+  | AvroNullSchema
+  | AvroBooleanSchema
+  | AvroIntSchema
+  | AvroLongSchema
+  | AvroFloatSchema
+  | AvroDoubleSchema
+  | AvroBytesSchema
+  | AvroStringSchema;
+
+// Union of all complex schemas
+export type AvroComplexSchema =
+  | AvroRecordSchema
+  | AvroEnumSchema
+  | AvroArraySchema
+  | AvroMapSchema
+  | AvroUnionSchema
+  | AvroFixedSchema;
+
+// Union of all schema types
+export type AvroSchema = AvroPrimitiveSchema | AvroComplexSchema | string;
+
+// Named schemas (record, enum, fixed)
+export type AvroNamedSchema = AvroRecordSchema | AvroEnumSchema | AvroFixedSchema;
+
+// Logical types - extensions to primitive types
+export interface AvroLogicalTypeSchema extends AvroBaseSchema {
+  /** The logical type name */
+  logicalType: string;
+}
+
+export interface AvroDecimalLogicalType extends AvroLogicalTypeSchema {
+  logicalType: 'decimal';
+  /** The maximum number of digits in the decimal */
+  precision: number;
+  /** The number of digits to the right of the decimal point */
+  scale?: number;
+}
+
+export interface AvroUuidLogicalType extends AvroStringSchema {
+  logicalType: 'uuid';
+}
+
+export interface AvroDateLogicalType extends AvroIntSchema {
+  logicalType: 'date';
+}
+
+export interface AvroTimeMillisLogicalType extends AvroIntSchema {
+  logicalType: 'time-millis';
+}
+
+export interface AvroTimeMicrosLogicalType extends AvroLongSchema {
+  logicalType: 'time-micros';
+}
+
+export interface AvroTimestampMillisLogicalType extends AvroLongSchema {
+  logicalType: 'timestamp-millis';
+}
+
+export interface AvroTimestampMicrosLogicalType extends AvroLongSchema {
+  logicalType: 'timestamp-micros';
+}
+
+export interface AvroLocalTimestampMillisLogicalType extends AvroLongSchema {
+  logicalType: 'local-timestamp-millis';
+}
+
+export interface AvroLocalTimestampMicrosLogicalType extends AvroLongSchema {
+  logicalType: 'local-timestamp-micros';
+}
+
+export interface AvroDurationLogicalType extends AvroFixedSchema {
+  logicalType: 'duration';
+  size: 12;
+}