improvement(block-inputs): must parse json accurately + models max_tokens fix (#3033)

* improvement(block-inputs): must parse json accurately

* fix sheets typing

* add reference comment

* fix models

* revert blocks changes

* fix param to follow openai new convention

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

@@ -28,6 +28,7 @@ import type {
 } from '@/executor/types'
 import { streamingResponseFormatProcessor } from '@/executor/utils'
 import { buildBlockExecutionError, normalizeError } from '@/executor/utils/errors'
+import { isJSONString } from '@/executor/utils/json'
 import { filterOutputForLog } from '@/executor/utils/output-filter'
 import { validateBlockType } from '@/executor/utils/permission-check'
 import type { VariableResolver } from '@/executor/variables/resolver'
@@ -86,7 +87,7 @@ export class BlockExecutor {
       resolvedInputs = this.resolver.resolveInputs(ctx, node.id, block.config.params, block)
 
       if (blockLog) {
-        blockLog.input = resolvedInputs
+        blockLog.input = this.parseJsonInputs(resolvedInputs)
       }
     } catch (error) {
       cleanupSelfReference?.()
@@ -157,7 +158,14 @@ export class BlockExecutor {
         const displayOutput = filterOutputForLog(block.metadata?.id || '', normalizedOutput, {
           block,
         })
-        this.callOnBlockComplete(ctx, node, block, resolvedInputs, displayOutput, duration)
+        this.callOnBlockComplete(
+          ctx,
+          node,
+          block,
+          this.parseJsonInputs(resolvedInputs),
+          displayOutput,
+          duration
+        )
       }
 
       return normalizedOutput
@@ -233,7 +241,7 @@ export class BlockExecutor {
       blockLog.durationMs = duration
       blockLog.success = false
       blockLog.error = errorMessage
-      blockLog.input = input
+      blockLog.input = this.parseJsonInputs(input)
       blockLog.output = filterOutputForLog(block.metadata?.id || '', errorOutput, { block })
     }
 
@@ -248,7 +256,14 @@ export class BlockExecutor {
 
     if (!isSentinel) {
       const displayOutput = filterOutputForLog(block.metadata?.id || '', errorOutput, { block })
-      this.callOnBlockComplete(ctx, node, block, input, displayOutput, duration)
+      this.callOnBlockComplete(
+        ctx,
+        node,
+        block,
+        this.parseJsonInputs(input),
+        displayOutput,
+        duration
+      )
     }
 
     const hasErrorPort = this.hasErrorPortEdge(node)
@@ -336,6 +351,36 @@ export class BlockExecutor {
     return { result: output }
   }
 
+  /**
+   * Parse JSON string inputs to objects for log display only.
+   * Attempts to parse any string that looks like JSON.
+   * Returns a new object - does not mutate the original inputs.
+   */
+  private parseJsonInputs(inputs: Record<string, any>): Record<string, any> {
+    let result = inputs
+    let hasChanges = false
+
+    for (const [key, value] of Object.entries(inputs)) {
+      // isJSONString is a quick heuristic (checks for { or [), not a validator.
+      // Invalid JSON is safely caught below - this just avoids JSON.parse on every string.
+      if (typeof value !== 'string' || !isJSONString(value)) {
+        continue
+      }
+
+      try {
+        if (!hasChanges) {
+          result = { ...inputs }
+          hasChanges = true
+        }
+        result[key] = JSON.parse(value.trim())
+      } catch {
+        // Not valid JSON, keep original string
+      }
+    }
+
+    return result
+  }
+
   private callOnBlockStart(ctx: ExecutionContext, node: DAGNode, block: SerializedBlock): void {
     const blockId = node.id
     const blockName = block.metadata?.name ?? blockId