Fix bizMonitor tool results failing DSH lossless JSON (strip undefined holes).

Co-authored-by: Cursor <cursoragent@cursor.com>

src/netx/handlers.ts

@@ -3,6 +3,7 @@
  */
 
 import { type NetxClient, quoteNeId, type NetxJson } from './http.ts'
+import { omitUndefined } from './json-safe.ts'
 
 const EXEC_MAX_COMMANDS = 5
 
@@ -343,7 +344,7 @@ function taskBriefNe(brief: unknown): string {
 
 function slimMigrationProject(row: NetxJson): NetxJson {
   const mt = asRecord(row.monitor_template)
-  return {
+  return omitUndefined({
     id: row.id,
     name: row.name,
     status: row.status,
@@ -360,7 +361,7 @@ function slimMigrationProject(row: NetxJson): NetxJson {
     hf_start_at: row.hf_start_at,
     hf_end_at: row.hf_end_at,
     updated_at: row.updated_at,
-  }
+  })
 }
 
 function matchesBizMonitorQ(row: NetxJson, q: string): boolean {
@@ -440,7 +441,7 @@ export async function listBizMonitors(
 
   return {
     ok: true,
-    data: {
+    data: omitUndefined({
       kind,
       projects: wantProjects ? projects : undefined,
       tasks: wantTasks ? tasks : undefined,
@@ -451,12 +452,12 @@ export async function listBizMonitors(
         tasks_returned: wantTasks ? tasks.length : 0,
       },
       next: 'Pass project_id (or task_id) to netx__getBizMonitorContext; then listBizMonitorBatches for batch_id / run_id.',
-    },
+    }),
   }
 }
 
 function slimCutoverBatch(row: NetxJson): NetxJson {
-  return {
+  return omitUndefined({
     id: row.id,
     project_id: row.project_id,
     batch_label: row.batch_label,
@@ -468,13 +469,13 @@ function slimCutoverBatch(row: NetxJson): NetxJson {
     note: row.note,
     created_at: row.created_at,
     updated_at: row.updated_at,
-  }
+  })
 }
 
 function slimCollectBatch(row: NetxJson, taskId = ''): NetxJson {
-  return {
+  return omitUndefined({
     id: row.id,
-    task_id: row.task_id || taskId,
+    task_id: row.task_id || taskId || undefined,
     status: row.status,
     ne_name: row.ne_name,
     command_count: row.command_count,
@@ -484,13 +485,13 @@ function slimCollectBatch(row: NetxJson, taskId = ''): NetxJson {
     message: row.message,
     started_at: row.started_at,
     ended_at: row.ended_at,
-  }
+  })
 }
 
 function slimEvalRun(row: NetxJson): NetxJson {
   const summary = asRecord(row.summary)
   const progress = asRecord(summary.progress)
-  return {
+  return omitUndefined({
     id: row.id,
     batch_id: row.batch_id,
     purpose: row.purpose,
@@ -500,7 +501,7 @@ function slimEvalRun(row: NetxJson): NetxJson {
     anomaly: summary.anomaly,
     progress_ok: progress.ok ?? summary.progress_ok,
     progress_total: progress.total ?? summary.progress_total,
-  }
+  })
 }
 
 /**
@@ -646,7 +647,7 @@ export async function listBizMonitorBatches(
 
   return {
     ok: true,
-    data: {
+    data: omitUndefined({
       kind,
       project_id: projectId || undefined,
       task_id: taskId || undefined,
@@ -664,7 +665,7 @@ export async function listBizMonitorBatches(
         : wantCollect
           ? 'Pass collect batch id to netx__getBizCollectBatch / getBizCollectCommandRaw.'
           : 'Pass run_id to netx__getBizMonitorDiffs or getBizMonitorBoard(run_id).',
-    },
+    }),
   }
 }
 

src/netx/json-safe.ts

@@ -0,0 +1,41 @@
+/**
+ * DSH tool outputs must be lossless JSON: no `undefined` property values,
+ * no NaN/Infinity, no class instances. Build plain objects carefully, or
+ * round-trip through JSON before returning from a tool.
+ */
+
+import type { NetxJson } from './http.ts'
+
+/**
+ * Detach a plain JSON-compatible value for DSH tool results.
+ * Drops object keys whose value is `undefined` (via JSON.stringify).
+ * @param value - handler result (may contain undefined holes).
+ * @returns parsed plain JSON object, or a safe error envelope.
+ */
+export function toLosslessJson(value: unknown): NetxJson {
+  try {
+    const text = JSON.stringify(value)
+    if (text === undefined) {
+      return { ok: false, error: 'tool_result_not_json', detail: 'undefined_root' }
+    }
+    const parsed: unknown = JSON.parse(text)
+    if (typeof parsed === 'object' && parsed !== null && !Array.isArray(parsed)) {
+      return parsed as NetxJson
+    }
+    return { ok: true, data: { value: parsed } }
+  } catch (error) {
+    const detail = error instanceof Error ? error.message : String(error)
+    return { ok: false, error: 'tool_result_not_json', detail: detail.slice(0, 400) }
+  }
+}
+
+/**
+ * Build a record omitting keys whose value is `undefined` (keeps null).
+ */
+export function omitUndefined(record: Record<string, unknown>): NetxJson {
+  const out: NetxJson = {}
+  for (const [key, value] of Object.entries(record)) {
+    if (value !== undefined) out[key] = value as NetxJson[string]
+  }
+  return out
+}

src/netx/kb-local-tools.ts

@@ -17,6 +17,7 @@ import {
 } from './kb-local-ops.ts'
 import { kbLocalToolsEnabled, resolveKbLocalRoot, type RefArea } from './kb-local-path.ts'
 import { getKbContext } from './kb-runtime.ts'
+import { toLosslessJson } from './json-safe.ts'
 
 const str = (description?: string) => ({ type: 'string' as const, ...(description ? { description } : {}) })
 const bool = (description?: string) => ({ type: 'boolean' as const, ...(description ? { description } : {}) })
@@ -56,7 +57,7 @@ function tool(
     isConcurrencySafe: () => false,
     async execute(args) {
       try {
-        return await execute(args as Record<string, unknown>)
+        return toLosslessJson(await execute(args as Record<string, unknown>))
       } catch (error) {
         throw new Error(error instanceof Error ? error.message : String(error))
       }

src/netx/tools.ts

@@ -11,6 +11,7 @@ import {
   type NetxCapabilityGroups,
 } from './capability-groups.ts'
 import { createNetxClient, type NetxClient, type NetxJson } from './http.ts'
+import { toLosslessJson } from './json-safe.ts'
 import { getNetxConnection } from './runtime.ts'
 import * as H from './handlers.ts'
 import * as T from './topology-handlers.ts'
@@ -74,10 +75,13 @@ function tool(
     isConcurrencySafe: () => true,
     async execute(args, exec) {
       const result = await handler(getClient(), args as NetxJson, exec.signal)
-      if (result.ok === false) {
-        throw new Error(JSON.stringify(result))
+      // DSH rejects tool results that contain `undefined` property holes
+      // ("value is not lossless JSON"). Round-trip strips them.
+      const safe = toLosslessJson(result)
+      if (result.ok === false || safe.ok === false) {
+        throw new Error(JSON.stringify(safe))
       }
-      return result
+      return safe
     },
   })
 }