diff --git a/core/interfaces/i_parameter_model.ts b/core/interfaces/i_parameter_model.ts
new file mode 100644
index 000000000..00d117240
--- /dev/null
+++ b/core/interfaces/i_parameter_model.ts
@@ -0,0 +1,35 @@
+/**
+ * @license
+ * Copyright 2022 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * The interface for the data model of a procedure parameter.
+ *
+ * @namespace Blockly.IParameterModel
+ */
+
+
+/**
+ * A data model for a procedure.
+ */
+export interface IParameterModel {
+  /**
+   * Sets the name of this parameter to the given name.
+   */
+  setName(name: string): this;
+
+  /**
+   * Sets the types of this parameter to the given type.
+   */
+  setTypes(types: string[]): this;
+
+  /**
+   * Returns the unique language-neutral ID for the parameter.
+   *
+   * This represents the identify of the variable model which does not change
+   * over time.
+   */
+  getId(): string;
+}
diff --git a/core/interfaces/i_procedure_model.ts b/core/interfaces/i_procedure_model.ts
new file mode 100644
index 000000000..1950fff76
--- /dev/null
+++ b/core/interfaces/i_procedure_model.ts
@@ -0,0 +1,70 @@
+/**
+ * @license
+ * Copyright 2022 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * The interface for the data model of a procedure.
+ *
+ * @namespace Blockly.IProcedureModel
+ */
+
+import {IParameterModel} from './i_parameter_model.js';
+
+
+/**
+ * A data model for a procedure.
+ */
+export interface IProcedureModel {
+  /** Sets the human-readable name of the procedure. */
+  setName(name: string): this;
+
+  /**
+   * Inserts a parameter into the list of parameters.
+   *
+   * To move a parameter, first delete it, and then re-insert.
+   */
+  insertParameter(parameterModel: IParameterModel, index: number): this;
+
+  /** Removes the parameter at the given index from the parameter list. */
+  deleteParameter(index: number): this;
+
+  /**
+   * Sets the return type(s) of the procedure.
+   *
+   * Pass null to represent a procedure that does not return.
+   */
+  setReturnTypes(types: string[]|null): this;
+
+  /**
+   * Sets whether this procedure is enabled/disabled. If a procedure is disabled
+   * all procedure caller blocks should be disabled as well.
+   */
+  setEnabled(enabled: boolean): this;
+
+  /** Returns the unique language-neutral ID for the procedure. */
+  getId(): string;
+
+  /** Returns the human-readable name of the procedure. */
+  getName(): string;
+
+  /** Returns the parameter at the given index in the parameter list. */
+  getParameter(index: number): IParameterModel;
+
+  /** Returns an array of all of the parameters in the parameter list. */
+  getParameters(): IParameterModel[];
+
+  /**
+   * Returns the return type(s) of the procedure.
+   *
+   * Null represents a procedure that does not return a value.
+   */
+  getReturnTypes(): string[]|null;
+
+  /**
+   * Returns whether the procedure is enabled/disabled. If a procedure is
+   * disabled, all procedure caller blocks should be disabled as well.
+   */
+  getEnabled(): boolean;
+}