fix(executor): preserve non-retryable tool failures

Author: Bill Leoutsakos

apps/sim/executor/execution/block-executor.retry.test.ts

@@ -10,10 +10,17 @@ import { BlockType, EDGE } from '@/executor/constants'
 import type { DAGNode } from '@/executor/dag/builder'
 import { BlockExecutor } from '@/executor/execution/block-executor'
 import { ExecutionState } from '@/executor/execution/state'
+import { GenericBlockHandler } from '@/executor/handlers/generic/generic-handler'
 import type { BlockHandler, ExecutionContext } from '@/executor/types'
 import { attachTrustedExecutionCost } from '@/executor/utils/errors'
 import { VariableResolver } from '@/executor/variables/resolver'
 import type { SerializedBlock, SerializedWorkflow } from '@/serializer/types'
+import { executeTool } from '@/tools'
+import { getTool } from '@/tools/utils'
+
+vi.mock('@/blocks/index', () => ({ getBlock: vi.fn() }))
+vi.mock('@/tools', () => ({ executeTool: vi.fn() }))
+vi.mock('@/tools/utils', () => ({ getTool: vi.fn() }))
 
 vi.mock('@/ee/access-control/utils/permission-check', () => ({
   validateBlockType: vi.fn(),
@@ -139,6 +146,40 @@ describe('BlockExecutor retry', () => {
     expect(ctx.blockLogs[0]?.tries).toBe(2)
   })
 
+  it.each([
+    { retryable: false, attempts: 1 },
+    { retryable: true, attempts: 3 },
+    { retryable: undefined, attempts: 3 },
+  ])(
+    'executes a generic tool $attempts times when retryable is $retryable',
+    async ({ retryable, attempts }) => {
+      const block = createBlock(enabled)
+      block.config.tool = 'synthetic_write'
+      vi.mocked(getTool).mockReturnValue({
+        id: 'synthetic_write',
+        name: 'Synthetic Write',
+        description: 'A synthetic write for retry testing',
+        version: '1.0',
+        params: {},
+        request: { url: 'https://example.com/write', method: 'POST' },
+      })
+      vi.mocked(executeTool).mockResolvedValue({
+        success: false,
+        error: 'Write outcome is unknown',
+        output: { detail: 'Response was lost' },
+        ...(retryable !== undefined ? { retryable } : {}),
+      })
+      const state = new ExecutionState()
+      const ctx = createContext(state)
+      const executor = buildExecutor(block, new GenericBlockHandler(), state)
+
+      await expect(executor.execute(ctx, createNode(block), block)).rejects.toThrow(
+        'Write outcome is unknown'
+      )
+      expect(executeTool).toHaveBeenCalledTimes(attempts)
+    }
+  )
+
   it('adds the trusted cost of failed Function tries to the successful result', async () => {
     const block = createBlock(enabled)
     const firstFailure = new Error('first attempt failed')

apps/sim/executor/handlers/generic/generic-handler.test.ts

@@ -1,6 +1,7 @@
 import '@sim/testing/mocks/executor'
 
 import { beforeEach, describe, expect, it, type Mock, vi } from 'vitest'
+import { NonRetryableExecutionError } from '@/lib/execution/non-retryable-error'
 import { HarmonicBlock } from '@/blocks/blocks/harmonic'
 import { KnowledgeBlock } from '@/blocks/blocks/knowledge'
 import { getBlock } from '@/blocks/index'
@@ -593,30 +594,42 @@ describe('GenericBlockHandler', () => {
     expect(mockExecuteTool).not.toHaveBeenCalled()
   })
 
-  it('should handle tool execution errors correctly', async () => {
-    const inputs = { param1: 'value' }
-    const errorResult = {
-      success: false,
-      error: 'Custom tool failed',
-      output: { detail: 'error detail' },
-    }
-    mockExecuteTool.mockResolvedValue(errorResult)
+  it.each([undefined, true, false])(
+    'preserves failure details when retryable is %s',
+    async (retryable) => {
+      const inputs = { param1: 'value' }
+      const errorResult = {
+        success: false,
+        error: 'Custom tool failed',
+        output: { detail: 'error detail' },
+        statusCode: 503,
+        ...(retryable !== undefined ? { retryable } : {}),
+      }
+      mockExecuteTool.mockResolvedValue(errorResult)
 
-    await expect(handler.execute(mockContext, mockBlock, inputs)).rejects.toThrow(
-      'Custom tool failed'
-    )
+      let thrown: unknown
+      try {
+        await handler.execute(mockContext, mockBlock, inputs)
+      } catch (error) {
+        thrown = error
+      }
 
-    // Re-execute to check error properties after catching
-    try {
-      await handler.execute(mockContext, mockBlock, inputs)
-    } catch (e: any) {
-      expect(e.toolId).toBe('some_custom_tool')
-      expect(e.blockName).toBe('Test Generic Block')
-      expect(e.output).toEqual({ detail: 'error detail' })
+      expect(thrown).toBeInstanceOf(Error)
+      expect(thrown instanceof NonRetryableExecutionError).toBe(retryable === false)
+      expect(thrown).toMatchObject({
+        message: 'Custom tool failed',
+        toolId: 'some_custom_tool',
+        toolName: 'Some Custom Tool',
+        blockId: 'generic-block-1',
+        blockName: 'Test Generic Block',
+        output: { detail: 'error detail' },
+        statusCode: 503,
+        timestamp: expect.any(String),
+        ...(retryable === false ? { retryable: false } : {}),
+      })
+      expect(mockExecuteTool).toHaveBeenCalledTimes(1)
     }
-
-    expect(mockExecuteTool).toHaveBeenCalledTimes(2) // Called twice now
-  })
+  )
 
   it.concurrent('should handle tool execution errors with no specific message', async () => {
     const inputs = { param1: 'value' }

apps/sim/executor/handlers/generic/generic-handler.ts

@@ -2,6 +2,7 @@ import { isDeepStrictEqual } from 'node:util'
 import { createLogger } from '@sim/logger'
 import { toError } from '@sim/utils/errors'
 import { isPlainRecord } from '@sim/utils/object'
+import { NonRetryableExecutionError } from '@/lib/execution/non-retryable-error'
 import { getBlock } from '@/blocks/index'
 import { isMcpTool } from '@/executor/constants'
 import type { BlockHandler, BlockNodeMetadata, ExecutionContext } from '@/executor/types'
@@ -344,7 +345,10 @@ export class GenericBlockHandler implements BlockHandler {
             ? errorDetails.join(' - ')
             : `Block execution of ${tool?.name || block.config.tool} failed with no error message`
 
-        const error = new Error(errorMessage)
+        const error =
+          result.retryable === false
+            ? new NonRetryableExecutionError(errorMessage)
+            : new Error(errorMessage)
 
         Object.assign(error, {
           toolId: block.config.tool,