diff --git a/packages/router/src/grpc/view-protocol-server/test-utils.ts b/packages/router/src/grpc/view-protocol-server/test-utils.ts
index 438926855d..b95f075437 100644
--- a/packages/router/src/grpc/view-protocol-server/test-utils.ts
+++ b/packages/router/src/grpc/view-protocol-server/test-utils.ts
@@ -9,6 +9,7 @@ export interface IndexedDbMock {
   getLastBlockSynced?: Mock;
   getSpendableNoteByCommitment?: Mock;
   getSpendableNoteByNullifier?: Mock;
+  getStateCommitmentTree?: Mock;
   getSwapByNullifier?: Mock;
   getTransactionInfo?: Mock;
   iterateTransactionInfo?: () => Partial<AsyncIterable<Mock>>;
diff --git a/packages/router/src/grpc/view-protocol-server/witness.test.ts b/packages/router/src/grpc/view-protocol-server/witness.test.ts
new file mode 100644
index 0000000000..15ae63adc8
--- /dev/null
+++ b/packages/router/src/grpc/view-protocol-server/witness.test.ts
@@ -0,0 +1,171 @@
+import { beforeEach, describe, expect, test, vi } from 'vitest';
+import {
+  WitnessRequest,
+  WitnessResponse,
+} from '@buf/penumbra-zone_penumbra.bufbuild_es/penumbra/view/v1/view_pb';
+import { ServicesInterface } from '@penumbra-zone/types';
+import { createContextValues, createHandlerContext, HandlerContext } from '@connectrpc/connect';
+import { ViewService } from '@buf/penumbra-zone_penumbra.connectrpc_es/penumbra/view/v1/view_connect';
+import { servicesCtx } from '../../ctx';
+import { IndexedDbMock, MockServices } from './test-utils';
+import { witness } from './witness';
+import {
+  TransactionPlan,
+  WitnessData,
+} from '@buf/penumbra-zone_penumbra.bufbuild_es/penumbra/core/transaction/v1/transaction_pb';
+
+describe('Witness request handler', () => {
+  let mockServices: MockServices;
+  let mockIndexedDb: IndexedDbMock;
+  let mockCtx: HandlerContext;
+  let req: WitnessRequest;
+
+  beforeEach(() => {
+    vi.resetAllMocks();
+
+    mockIndexedDb = {
+      getStateCommitmentTree: vi.fn(),
+    };
+    mockServices = {
+      getWalletServices: vi.fn(() => Promise.resolve({ indexedDb: mockIndexedDb })),
+    };
+    mockCtx = createHandlerContext({
+      service: ViewService,
+      method: ViewService.methods.witness,
+      protocolName: 'mock',
+      requestMethod: 'MOCK',
+      contextValues: createContextValues().set(
+        servicesCtx,
+        mockServices as unknown as ServicesInterface,
+      ),
+    });
+    req = new WitnessRequest({
+      transactionPlan: testPlan,
+    });
+  });
+
+  test('should successfully create witness data', async () => {
+    mockIndexedDb.getStateCommitmentTree?.mockResolvedValue(testSct);
+    const witnessResponse = new WitnessResponse(await witness(req, mockCtx));
+    expect(witnessResponse.witnessData).instanceof(WitnessData);
+  });
+
+  test('should throw error if transaction plan is missing in request', async () => {
+    await expect(witness(new WitnessRequest(), mockCtx)).rejects.toThrow();
+  });
+});
+
+const testSct = {
+  last_position: { Position: { epoch: 5, block: 51, commitment: 0 } },
+  last_forgotten: 0n,
+  hashes: [],
+  commitments: [
+    {
+      position: { epoch: 5, block: 40, commitment: 1 },
+      commitment: {
+        inner: '+et9QvGlWAzKXPYBEiUQ3zrACaOOoEZTdM0Ru+/22Q0=',
+      },
+    },
+  ],
+};
+const testPlan = TransactionPlan.fromJson({
+  actions: [
+    {
+      output: {
+        value: {
+          amount: {
+            lo: '17000000',
+          },
+          assetId: {
+            inner: 'KeqcLzNx9qSH5+lcJHBB9KNW+YPrBk5dKzvPMiypahA=',
+          },
+        },
+        destAddress: {
+          inner:
+            '0AI1VPl2Z2iM62nnBX+o00kL3Fcvcqm8zgp0ErDpw4hT2syB5TeaGJM8B+5KV+/3CS78toGM3WleoNgPh/7L9bKNOrmq7UEqBmfAb7MDI+w=',
+        },
+        rseed: '/3i6n9kAwHRK7BglIH0QWZcwVjYeIhXcETFjgw4quNg=',
+        valueBlinding: 'oN/74T2n6BCbAD9fexKTYN7/EdgamOhzu0T1CaCyvwA=',
+        proofBlindingR: 'dx8BFun9Ecae4G5K35O+odpgIiW38Si/8af6v3BbiAI=',
+        proofBlindingS: 'tAK8dKHm4QfTmPDazgGeODGmz7NAcRZZqNjc5ngdsgA=',
+      },
+    },
+    {
+      spend: {
+        note: {
+          value: {
+            amount: {
+              lo: '999978000000',
+            },
+            assetId: {
+              inner: 'KeqcLzNx9qSH5+lcJHBB9KNW+YPrBk5dKzvPMiypahA=',
+            },
+          },
+          rseed: 'H/Fy4tVGBPaCmYr7xskZ0cEhD79fj0bm/P2goI7NE+g=',
+          address: {
+            inner:
+              'H54tVYCe2KONaws0+4Qt8jHSup2InYWauNEGtLa7+yQ8ssaP1Qc2bjsB7uyfQl3QKMXzfm3u70/CbK9tOiSXjDtDzx3AtQw2wKCeuht3Ono=',
+          },
+        },
+        position: '21477457921',
+        randomizer: 'H7NTioroyZVJ/axRjF9rFOTraMKY4/oI5rZ5ioc5XAI=',
+        valueBlinding: 'A8uFN42ZUkmm7K+mfMMIjrXWhQRR7gDSuFoHbUS63QI=',
+        proofBlindingR: 'oDcDqoOeA+cmJx9+85o3NjBO5F7czVTdpgZsd6AF0hE=',
+        proofBlindingS: 'AgGH9qmBSNerolyHPBfwjUn1hSR5o3asMrWflj4wrQk=',
+      },
+    },
+    {
+      output: {
+        value: {
+          amount: {
+            lo: '999961000000',
+          },
+          assetId: {
+            inner: 'KeqcLzNx9qSH5+lcJHBB9KNW+YPrBk5dKzvPMiypahA=',
+          },
+        },
+        destAddress: {
+          inner:
+            'H54tVYCe2KONaws0+4Qt8jHSup2InYWauNEGtLa7+yQ8ssaP1Qc2bjsB7uyfQl3QKMXzfm3u70/CbK9tOiSXjDtDzx3AtQw2wKCeuht3Ono=',
+        },
+        rseed: 'fk7N8WEob+bgE/i0CZgmHGP8e0mGFHjKW2yzC7zKoUY=',
+        valueBlinding: 'TFPHBogTl0+n+aSf0X4ygrQ+i6Mc9s3a+6jbTTlidQA=',
+        proofBlindingR: 'uxySUkOiKig72CiH6q5Lx+5bDkGko4SxhJ+pZVuTohE=',
+        proofBlindingS: 'UKzlbj48dd24R2yl4UwB8vU8Lda1TN5+qGpQ8jFsIgQ=',
+      },
+    },
+  ],
+  transactionParameters: {
+    chainId: 'penumbra-testnet-deimos-2-38b9a683',
+    fee: {
+      amount: {},
+    },
+  },
+  detectionData: {
+    cluePlans: [
+      {
+        address: {
+          inner:
+            '0AI1VPl2Z2iM62nnBX+o00kL3Fcvcqm8zgp0ErDpw4hT2syB5TeaGJM8B+5KV+/3CS78toGM3WleoNgPh/7L9bKNOrmq7UEqBmfAb7MDI+w=',
+        },
+        rseed: 'dDfkKQanWSTxc5w7su42ru+tTnD6xbJUJBhEGbpOY/8=',
+      },
+      {
+        address: {
+          inner:
+            'H54tVYCe2KONaws0+4Qt8jHSup2InYWauNEGtLa7+yQ8ssaP1Qc2bjsB7uyfQl3QKMXzfm3u70/CbK9tOiSXjDtDzx3AtQw2wKCeuht3Ono=',
+        },
+        rseed: 'V3Vvhh7r9/1P/XmJrlwrFmeUhQ9JzbYbS+0GvhsHnIQ=',
+      },
+    ],
+  },
+  memo: {
+    plaintext: {
+      returnAddress: {
+        inner:
+          'H54tVYCe2KONaws0+4Qt8jHSup2InYWauNEGtLa7+yQ8ssaP1Qc2bjsB7uyfQl3QKMXzfm3u70/CbK9tOiSXjDtDzx3AtQw2wKCeuht3Ono=',
+      },
+    },
+    key: 'y1Hc7R18awsR3rxn3EWaBDmWHYMiFVhC2gviFG7FA90=',
+  },
+});