diff --git a/src/__tests__/unit/gateway-interactions.loader.test.ts b/src/__tests__/unit/gateway-interactions.loader.test.ts
index 05410926..f22ab5fd 100644
--- a/src/__tests__/unit/gateway-interactions.loader.test.ts
+++ b/src/__tests__/unit/gateway-interactions.loader.test.ts
@@ -1,6 +1,7 @@
 import Arweave from 'arweave';
 import { LexicographicalInteractionsSorter } from '../../core/modules/impl/LexicographicalInteractionsSorter';
 import { WarpGatewayInteractionsLoader } from '../../core/modules/impl/WarpGatewayInteractionsLoader';
+import { InteractionsLoaderError } from '../../core/modules/InteractionsLoader';
 import { GQLNodeInterface } from '../../legacy/gqlResult';
 import { LoggerFactory } from '../../logging/LoggerFactory';
 
@@ -140,8 +141,9 @@ describe('WarpGatewayInteractionsLoader -> load', () => {
     const loader = new WarpGatewayInteractionsLoader('http://baseUrl');
     try {
       await loader.load(contractId, fromBlockHeight, toBlockHeight);
-    } catch (e) {
-      expect(e).toEqual(new Error('Unable to retrieve transactions. Warp gateway responded with status 504.'));
+    } catch (rawError) {
+      const error = rawError as InteractionsLoaderError;
+      expect(error.detail.type === 'BadGatewayResponse' && error.detail.status === 504).toBeTruthy();
     }
   });
   it('should throw an error when request fails', async () => {
@@ -151,8 +153,9 @@ describe('WarpGatewayInteractionsLoader -> load', () => {
     const loader = new WarpGatewayInteractionsLoader('http://baseUrl');
     try {
       await loader.load(contractId, fromBlockHeight, toBlockHeight);
-    } catch (e) {
-      expect(e).toEqual(new Error('Unable to retrieve transactions. Warp gateway responded with status 500.'));
+    } catch (rawError) {
+      const error = rawError as InteractionsLoaderError;
+      expect(error.detail.type === 'BadGatewayResponse' && error.detail.status === 500).toBeTruthy();
     }
   });
 });
diff --git a/src/contract/Contract.ts b/src/contract/Contract.ts
index 4376c773..5bc279a1 100644
--- a/src/contract/Contract.ts
+++ b/src/contract/Contract.ts
@@ -1,3 +1,5 @@
+import { BadGatewayResponse } from '../core/modules/InteractionsLoader';
+import { CustomError, Err } from '../utils/CustomError';
 import Transaction from 'arweave/node/lib/transaction';
 import { SortKeyCacheResult } from '../cache/SortKeyCache';
 import { ContractCallRecord } from '../core/ContractCallRecord';
@@ -12,12 +14,23 @@ export type BenchmarkStats = { gatewayCommunication: number; stateEvaluation: nu
 
 export type SigningFunction = (tx: Transaction) => Promise<void>;
 
-export class ContractError extends Error {
-  constructor(message) {
-    super(message);
-    this.name = 'ContractError';
-  }
-}
+// Make these two error cases individual as they could be used in different places
+export type NoWalletConnected = Err<'NoWalletConnected'>;
+export type InvalidInteraction = Err<'InvalidInteraction'>;
+
+export type BundleInteractionErrorDetail =
+  | NoWalletConnected
+  | InvalidInteraction
+  | BadGatewayResponse
+  | Err<'CannotBundle'>;
+export class BundleInteractionError extends CustomError<BundleInteractionErrorDetail> {}
+
+// export class ContractError extends Error {
+//   constructor(message) {
+//     super(message);
+//     this.name = 'ContractError';
+//   }
+// }
 
 interface BundlrResponse {
   id: string;
diff --git a/src/contract/HandlerBasedContract.ts b/src/contract/HandlerBasedContract.ts
index 3598ffaa..6d9ee9cb 100644
--- a/src/contract/HandlerBasedContract.ts
+++ b/src/contract/HandlerBasedContract.ts
@@ -30,12 +30,14 @@ import {
   CurrentTx,
   WriteInteractionOptions,
   WriteInteractionResponse,
-  InnerCallData
+  InnerCallData,
+  BundleInteractionError
 } from './Contract';
 import { Tags, ArTransfer, emptyTransfer, ArWallet } from './deploy/CreateContract';
 import { SourceData, SourceImpl } from './deploy/impl/SourceImpl';
 import { InnerWritesEvaluator } from './InnerWritesEvaluator';
 import { generateMockVrf } from '../utils/vrf';
+import { InteractionsLoaderError } from '../core/modules/InteractionsLoader';
 
 /**
  * An implementation of {@link Contract} that is backwards compatible with current style
@@ -280,15 +282,30 @@ export class HandlerBasedContract<State> implements Contract<State> {
     }
   ): Promise<WriteInteractionResponse | null> {
     this.logger.info('Bundle interaction input', input);
+    if (!this.signer) {
+      throw new BundleInteractionError(
+        { type: 'NoWalletConnected' },
+        "Wallet not connected. Use 'connect' method first."
+      );
+    }
 
-    const interactionTx = await this.createInteraction(
-      input,
-      options.tags,
-      emptyTransfer,
-      options.strict,
-      true,
-      options.vrf
-    );
+    let interactionTx: Transaction;
+    try {
+      interactionTx = await this.createInteraction(
+        input,
+        options.tags,
+        emptyTransfer,
+        options.strict,
+        true,
+        options.vrf
+      );
+    } catch (e) {
+      if (e instanceof InteractionsLoaderError) {
+        throw new BundleInteractionError(e.detail, `${e}`, e);
+      } else {
+        throw new BundleInteractionError({ type: 'InvalidInteraction' }, `${e}`, e);
+      }
+    }
 
     const response = await fetch(`${this._evaluationOptions.bundlerUrl}gateway/sequencer/register`, {
       method: 'POST',
@@ -308,7 +325,10 @@ export class HandlerBasedContract<State> implements Contract<State> {
         if (error.body?.message) {
           this.logger.error(error.body.message);
         }
-        throw new Error(`Unable to bundle interaction: ${JSON.stringify(error)}`);
+        throw new BundleInteractionError(
+          { type: 'CannotBundle' },
+          `Unable to bundle interaction: ${JSON.stringify(error)}`
+        );
       });
 
     return {
@@ -336,7 +356,7 @@ export class HandlerBasedContract<State> implements Contract<State> {
       const handlerResult = await this.callContract(input, undefined, undefined, tags, transfer, strict, vrf);
 
       if (strict && handlerResult.type !== 'ok') {
-        throw Error(`Cannot create interaction: ${handlerResult.errorMessage}`);
+        throw new Error(`Cannot create interaction: ${handlerResult.errorMessage}`);
       }
       const callStack: ContractCallRecord = this.getCallStack();
       const innerWrites = this._innerWritesEvaluator.eval(callStack);
@@ -355,7 +375,7 @@ export class HandlerBasedContract<State> implements Contract<State> {
       if (strict) {
         const handlerResult = await this.callContract(input, undefined, undefined, tags, transfer, strict, vrf);
         if (handlerResult.type !== 'ok') {
-          throw Error(`Cannot create interaction: ${handlerResult.errorMessage}`);
+          throw new Error(`Cannot create interaction: ${handlerResult.errorMessage}`);
         }
       }
     }
diff --git a/src/core/modules/InteractionsLoader.ts b/src/core/modules/InteractionsLoader.ts
index 3bbc7c20..b058619b 100644
--- a/src/core/modules/InteractionsLoader.ts
+++ b/src/core/modules/InteractionsLoader.ts
@@ -1,6 +1,15 @@
+import { CustomError, Err } from '../../utils/CustomError';
 import { GQLNodeInterface } from '../../legacy/gqlResult';
 import { EvaluationOptions } from './StateEvaluator';
 
+// Make this error case individual as it is also used in `src/contract/Contract.ts`.
+export type BadGatewayResponse = Err<'BadGatewayResponse'> & { status: number };
+
+// InteractionsLoaderErrorDetail is effectively only an alias to BadGatewayResponse but it could
+// also include other kinds of errors in the future.
+export type InteractionsLoaderErrorDetail = BadGatewayResponse;
+export class InteractionsLoaderError extends CustomError<InteractionsLoaderErrorDetail> {}
+
 export type GW_TYPE = 'arweave' | 'warp';
 
 export interface GwTypeAware {
diff --git a/src/core/modules/impl/WarpGatewayInteractionsLoader.ts b/src/core/modules/impl/WarpGatewayInteractionsLoader.ts
index aefffeb9..a59a716f 100644
--- a/src/core/modules/impl/WarpGatewayInteractionsLoader.ts
+++ b/src/core/modules/impl/WarpGatewayInteractionsLoader.ts
@@ -3,7 +3,7 @@ import { Benchmark } from '../../../logging/Benchmark';
 import { LoggerFactory } from '../../../logging/LoggerFactory';
 import 'redstone-isomorphic';
 import { stripTrailingSlash } from '../../../utils/utils';
-import { GW_TYPE, InteractionsLoader } from '../InteractionsLoader';
+import { GW_TYPE, InteractionsLoader, InteractionsLoaderError } from '../InteractionsLoader';
 import { EvaluationOptions } from '../StateEvaluator';
 
 export type ConfirmationStatus =
@@ -91,7 +91,8 @@ export class WarpGatewayInteractionsLoader implements InteractionsLoader {
           if (error.body?.message) {
             this.logger.error(error.body.message);
           }
-          throw new Error(`Unable to retrieve transactions. Warp gateway responded with status ${error.status}.`);
+          const errorMessage = `Unable to retrieve transactions. Redstone gateway responded with status ${error.status}.`;
+          throw new InteractionsLoaderError({ type: 'BadGatewayResponse', status: error.status }, errorMessage, error);
         });
       this.logger.debug(`Loading interactions: page ${page} loaded in ${benchmarkRequestTime.elapsed()}`);
 
diff --git a/src/core/modules/impl/handler/AbstractContractHandler.ts b/src/core/modules/impl/handler/AbstractContractHandler.ts
index 0c4a82ff..e95b6c32 100644
--- a/src/core/modules/impl/handler/AbstractContractHandler.ts
+++ b/src/core/modules/impl/handler/AbstractContractHandler.ts
@@ -1,4 +1,4 @@
-import { ContractError, CurrentTx } from '../../../../contract/Contract';
+import { CurrentTx } from '../../../../contract/Contract';
 import { ContractDefinition } from '../../../../core/ContractDefinition';
 import { ExecutionContext } from '../../../../core/ExecutionContext';
 import { EvalStateResult } from '../../../../core/modules/StateEvaluator';
@@ -89,7 +89,7 @@ export abstract class AbstractContractHandler<State> implements HandlerApi<State
         }
       });
       if (shouldAutoThrow) {
-        throw new ContractError(effectiveErrorMessage);
+        throw new Error(effectiveErrorMessage);
       }
 
       return result;
diff --git a/src/utils/CustomError.ts b/src/utils/CustomError.ts
new file mode 100644
index 00000000..541b8e7f
--- /dev/null
+++ b/src/utils/CustomError.ts
@@ -0,0 +1,15 @@
+/**
+ * A helper type to avoid having to type `{ type: "..." }` for every error detail types.
+ */
+export type Err<T extends string> = { type: T };
+
+/**
+ * The custom error type that every error originating from the library should extend.
+ */
+export class CustomError<T extends { type: string }> extends Error {
+  constructor(public detail: T, message?: string, public originalError?: unknown) {
+    super(`${detail.type}${message ? `: ${message}` : ''}`);
+    this.name = 'CustomError';
+    Error.captureStackTrace(this, CustomError);
+  }
+}