diff --git a/apps/sim/app/api/mothership/execute/route.ts b/apps/sim/app/api/mothership/execute/route.ts
index 37236aa160f..fa227d69351 100644
--- a/apps/sim/app/api/mothership/execute/route.ts
+++ b/apps/sim/app/api/mothership/execute/route.ts
@@ -8,6 +8,7 @@ import { checkInternalAuth } from '@/lib/auth/hybrid'
 import { buildIntegrationToolSchemas } from '@/lib/copilot/chat/payload'
 import { processContextsServer } from '@/lib/copilot/chat/process-contents'
 import { generateWorkspaceContext } from '@/lib/copilot/chat/workspace-context'
+import { computeWorkspaceEntitlements } from '@/lib/copilot/entitlements'
 import {
   MothershipStreamV1EventType,
   MothershipStreamV1TextChannel,
@@ -141,25 +142,32 @@ export const POST = withRouteHandler(async (req: NextRequest) => {
     const lastUserMessage = messages.filter((m) => m.role === 'user').at(-1)?.content
     // double-cast-allowed: the contract validates contexts as open kind/label objects; processContextsServer narrows on `kind` at runtime
     const agentMentions = contexts as unknown as ChatContext[] | undefined
-    const [workspaceContext, integrationTools, userSkillTool, userPermission, agentContexts] =
-      await Promise.all([
-        generateWorkspaceContext(workspaceId, userId),
-        buildIntegrationToolSchemas(userId, messageId, undefined, workspaceId),
-        buildUserSkillTool(workspaceId),
-        getUserEntityPermissions(userId, 'workspace', workspaceId).catch(() => null),
-        processContextsServer(
-          agentMentions,
-          userId,
-          lastUserMessage,
-          workspaceId,
-          effectiveChatId
-        ).catch((error) => {
-          reqLogger.warn('Failed to resolve agent contexts for execution', {
-            error: toError(error).message,
-          })
-          return []
-        }),
-      ])
+    const [
+      workspaceContext,
+      integrationTools,
+      userSkillTool,
+      userPermission,
+      entitlements,
+      agentContexts,
+    ] = await Promise.all([
+      generateWorkspaceContext(workspaceId, userId),
+      buildIntegrationToolSchemas(userId, messageId, undefined, workspaceId),
+      buildUserSkillTool(workspaceId),
+      getUserEntityPermissions(userId, 'workspace', workspaceId).catch(() => null),
+      computeWorkspaceEntitlements(workspaceId, userId),
+      processContextsServer(
+        agentMentions,
+        userId,
+        lastUserMessage,
+        workspaceId,
+        effectiveChatId
+      ).catch((error) => {
+        reqLogger.warn('Failed to resolve agent contexts for execution', {
+          error: toError(error).message,
+        })
+        return []
+      }),
+    ])
     const requestPayload: Record<string, unknown> = {
       messages,
       responseFormat,
@@ -182,6 +190,7 @@ export const POST = withRouteHandler(async (req: NextRequest) => {
       ...(integrationTools.length > 0 ? { integrationTools } : {}),
       ...(userSkillTool ? { mothershipTools: [userSkillTool] } : {}),
       ...(userPermission ? { userPermission } : {}),
+      ...(entitlements.length > 0 ? { entitlements } : {}),
     }
 
     let allowExplicitAbort = true
diff --git a/apps/sim/lib/copilot/chat/payload.test.ts b/apps/sim/lib/copilot/chat/payload.test.ts
index 1afbfbbaac3..ee050104ec1 100644
--- a/apps/sim/lib/copilot/chat/payload.test.ts
+++ b/apps/sim/lib/copilot/chat/payload.test.ts
@@ -227,4 +227,34 @@ describe('buildCopilotRequestPayload', () => {
       })
     )
   })
+
+  it('passes entitlements through and omits the field when empty', async () => {
+    const withEntitlements = await buildCopilotRequestPayload(
+      {
+        message: 'publish as a block',
+        userId: 'user-1',
+        userMessageId: 'msg-1',
+        mode: 'agent',
+        model: 'claude-opus-4-8',
+        workspaceId: 'ws-1',
+        entitlements: ['custom-blocks'],
+      },
+      { selectedModel: 'claude-opus-4-8' }
+    )
+    expect(withEntitlements).toEqual(expect.objectContaining({ entitlements: ['custom-blocks'] }))
+
+    const withoutEntitlements = await buildCopilotRequestPayload(
+      {
+        message: 'publish as a block',
+        userId: 'user-1',
+        userMessageId: 'msg-1',
+        mode: 'agent',
+        model: 'claude-opus-4-8',
+        workspaceId: 'ws-1',
+        entitlements: [],
+      },
+      { selectedModel: 'claude-opus-4-8' }
+    )
+    expect(withoutEntitlements).not.toHaveProperty('entitlements')
+  })
 })
diff --git a/apps/sim/lib/copilot/chat/payload.ts b/apps/sim/lib/copilot/chat/payload.ts
index e718b33cce3..6af11bd8683 100644
--- a/apps/sim/lib/copilot/chat/payload.ts
+++ b/apps/sim/lib/copilot/chat/payload.ts
@@ -36,6 +36,8 @@ interface BuildPayloadParams {
   workspaceContext?: string
   vfs?: VfsSnapshotV1
   userPermission?: string
+  /** Plan/flag-gated org capabilities (e.g. "custom-blocks") the mothership gates tools/prompts on. */
+  entitlements?: string[]
   userTimezone?: string
   userMetadata?: {
     name?: string
@@ -370,6 +372,7 @@ export async function buildCopilotRequestPayload(
     ...(params.workspaceContext ? { workspaceContext: params.workspaceContext } : {}),
     ...(params.vfs ? { vfs: params.vfs } : {}),
     ...(params.userPermission ? { userPermission: params.userPermission } : {}),
+    ...(params.entitlements?.length ? { entitlements: params.entitlements } : {}),
     ...(params.userTimezone ? { userTimezone: params.userTimezone } : {}),
     ...(params.userMetadata &&
     (params.userMetadata.name || params.userMetadata.email || params.userMetadata.timezone)
diff --git a/apps/sim/lib/copilot/chat/post.ts b/apps/sim/lib/copilot/chat/post.ts
index ca5943ae3b7..99345d240e6 100644
--- a/apps/sim/lib/copilot/chat/post.ts
+++ b/apps/sim/lib/copilot/chat/post.ts
@@ -25,6 +25,7 @@ import { finalizeAssistantTurn } from '@/lib/copilot/chat/terminal-state'
 import { generateWorkspaceSnapshot } from '@/lib/copilot/chat/workspace-context'
 import { chatPubSub } from '@/lib/copilot/chat-status'
 import { COPILOT_REQUEST_MODES } from '@/lib/copilot/constants'
+import { computeWorkspaceEntitlements } from '@/lib/copilot/entitlements'
 import {
   CopilotChatFinalizeOutcome,
   CopilotChatPersistOutcome,
@@ -175,6 +176,7 @@ type UnifiedChatBranch =
         contexts: Array<{ type: string; content: string; tag?: string; path?: string }>
         fileAttachments?: UnifiedChatRequest['fileAttachments']
         userPermission?: string
+        entitlements?: string[]
         userTimezone?: string
         userMetadata?: { name?: string; email?: string; timezone?: string }
         workflowId: string
@@ -212,6 +214,7 @@ type UnifiedChatBranch =
         contexts: Array<{ type: string; content: string; tag?: string; path?: string }>
         fileAttachments?: UnifiedChatRequest['fileAttachments']
         userPermission?: string
+        entitlements?: string[]
         userTimezone?: string
         userMetadata?: { name?: string; email?: string; timezone?: string }
         workspaceContext?: string
@@ -624,6 +627,7 @@ async function resolveBranch(params: {
             workspaceContext: payloadParams.workspaceContext,
             vfs: payloadParams.vfs,
             userPermission: payloadParams.userPermission,
+            entitlements: payloadParams.entitlements,
             userTimezone: payloadParams.userTimezone,
             userMetadata: payloadParams.userMetadata,
           },
@@ -679,6 +683,7 @@ async function resolveBranch(params: {
           workspaceContext: payloadParams.workspaceContext,
           vfs: payloadParams.vfs,
           userPermission: payloadParams.userPermission,
+          entitlements: payloadParams.entitlements,
           userTimezone: payloadParams.userTimezone,
           userMetadata: payloadParams.userMetadata,
           includeMothershipTools: true,
@@ -899,6 +904,9 @@ export async function handleUnifiedChatPost(req: NextRequest) {
                 }
               )
             : Promise.resolve(null)
+      const entitlementsPromise = workspaceId
+        ? computeWorkspaceEntitlements(workspaceId, authenticatedUserId)
+        : Promise.resolve([])
       // Wrap the pre-LLM prep work in spans so the trace waterfall shows
       // where time is going between "request received" and "llm.stream
       // opens". Previously these ran bare under the root and inflated the
@@ -953,10 +961,11 @@ export async function handleUnifiedChatPost(req: NextRequest) {
         activeOtelRoot.context
       )
 
-      const [agentContexts, userPermission, workspaceSnapshot, , executionContext] =
+      const [agentContexts, userPermission, entitlements, workspaceSnapshot, , executionContext] =
         await Promise.all([
           agentContextsPromise,
           userPermissionPromise,
+          entitlementsPromise,
           workspaceContextPromise,
           persistUserMessagePromise,
           executionContextPromise,
@@ -991,6 +1000,7 @@ export async function handleUnifiedChatPost(req: NextRequest) {
                 contexts: agentContexts,
                 fileAttachments: body.fileAttachments,
                 userPermission: userPermission ?? undefined,
+                entitlements,
                 userTimezone: body.userTimezone,
                 userMetadata,
                 workflowId: branch.workflowId,
@@ -1012,6 +1022,7 @@ export async function handleUnifiedChatPost(req: NextRequest) {
                 contexts: agentContexts,
                 fileAttachments: body.fileAttachments,
                 userPermission: userPermission ?? undefined,
+                entitlements,
                 userTimezone: body.userTimezone,
                 userMetadata,
                 workspaceContext,
diff --git a/apps/sim/lib/copilot/entitlements.ts b/apps/sim/lib/copilot/entitlements.ts
new file mode 100644
index 00000000000..8ef560cacea
--- /dev/null
+++ b/apps/sim/lib/copilot/entitlements.ts
@@ -0,0 +1,72 @@
+import { createLogger } from '@sim/logger'
+import { getErrorMessage } from '@sim/utils/errors'
+import { LRUCache } from 'lru-cache'
+import { isCustomBlocksEligible } from '@/lib/workflows/custom-blocks/operations'
+
+const logger = createLogger('CopilotEntitlements')
+
+/**
+ * Cross-repo contract: the mothership (Go) matches these exact strings against
+ * its `core.Entitlement*` constants to gate agent surfaces.
+ */
+export const CUSTOM_BLOCKS_ENTITLEMENT = 'custom-blocks'
+
+/**
+ * Workspace entitlements — plan/flag-gated org capabilities sent to the
+ * mothership as the chat payload's `entitlements` array. The Go side hides the
+ * matching tools, skills, and prompt sections when an entitlement is absent, so
+ * a non-entitled org's agents never hear of the feature.
+ *
+ * Adding an entitlement:
+ * 1. Add the kebab-case name and a fail-closed evaluator here. Every payload
+ *    site (interactive chat, headless execute, inbox) picks it up automatically.
+ * 2. Go repo: add the matching `Entitlement*` constant in `internal/core` and
+ *    gate surfaces declaratively — `RequiredEntitlement` on tool definitions,
+ *    `entitlement:` frontmatter on skills, a conditional section in
+ *    `BuildAgentEnvelope`, or a variant swap in `Capabilities`.
+ * 3. Keep enforcement in sim: the Go gating is advertisement-only (the payload
+ *    is forgeable), so the sim-side tool handler must re-check the same
+ *    predicate at execution time.
+ */
+const ENTITLEMENT_EVALUATORS: Record<
+  string,
+  (workspaceId: string, userId?: string) => Promise<boolean>
+> = {
+  [CUSTOM_BLOCKS_ENTITLEMENT]: isCustomBlocksEligible,
+}
+
+const entitlementsCache = new LRUCache<string, Promise<string[]>>({
+  max: 500,
+  ttl: 5_000,
+})
+
+/**
+ * The entitlements to send to the mothership for a request in this workspace.
+ * Each evaluator fails closed (an error means the entitlement is absent).
+ * Cached briefly so the several per-message callers collapse to one evaluation.
+ */
+export function computeWorkspaceEntitlements(
+  workspaceId: string,
+  userId?: string
+): Promise<string[]> {
+  const cacheKey = `${workspaceId}:${userId ?? ''}`
+  const cached = entitlementsCache.get(cacheKey)
+  if (cached) return cached
+
+  const promise = Promise.all(
+    Object.entries(ENTITLEMENT_EVALUATORS).map(async ([name, evaluate]) => {
+      try {
+        return (await evaluate(workspaceId, userId)) ? name : null
+      } catch (error) {
+        logger.warn('Entitlement evaluation failed; treating as absent', {
+          entitlement: name,
+          workspaceId,
+          error: getErrorMessage(error),
+        })
+        return null
+      }
+    })
+  ).then((names) => names.filter((name): name is string => name !== null))
+  entitlementsCache.set(cacheKey, promise)
+  return promise
+}
diff --git a/apps/sim/lib/copilot/generated/tool-catalog-v1.ts b/apps/sim/lib/copilot/generated/tool-catalog-v1.ts
index 4a4c24a1594..ffa1866a79c 100644
--- a/apps/sim/lib/copilot/generated/tool-catalog-v1.ts
+++ b/apps/sim/lib/copilot/generated/tool-catalog-v1.ts
@@ -23,6 +23,7 @@ export interface ToolCatalogEntry {
     | 'deploy'
     | 'deploy_api'
     | 'deploy_chat'
+    | 'deploy_custom_block'
     | 'deploy_mcp'
     | 'diff_workflows'
     | 'download_to_workspace_file'
@@ -121,6 +122,7 @@ export interface ToolCatalogEntry {
     | 'deploy'
     | 'deploy_api'
     | 'deploy_chat'
+    | 'deploy_custom_block'
     | 'deploy_mcp'
     | 'diff_workflows'
     | 'download_to_workspace_file'
@@ -536,7 +538,7 @@ export const Deploy: ToolCatalogEntry = {
     properties: {
       request: {
         description:
-          'Detailed deployment instructions. Include deployment type (api/chat/mcp) and ALL user-specified options: identifier, title, description, authType, password, allowedEmails, welcomeMessage, outputConfigs (block outputs to display).',
+          'Detailed deployment instructions. Include the deployment type and ALL user-specified options: identifier, title, description, authType, password, allowedEmails, welcomeMessage, outputConfigs (block outputs to display).',
         type: 'string',
       },
     },
@@ -772,6 +774,118 @@ export const DeployChat: ToolCatalogEntry = {
   requiredPermission: 'admin',
 }
 
+export const DeployCustomBlock: ToolCatalogEntry = {
+  id: 'deploy_custom_block',
+  name: 'deploy_custom_block',
+  route: 'sim',
+  mode: 'async',
+  parameters: {
+    type: 'object',
+    properties: {
+      action: {
+        type: 'string',
+        description: 'Whether to publish (deploy) or unpublish (undeploy) the custom block',
+        enum: ['deploy', 'undeploy'],
+        default: 'deploy',
+      },
+      description: {
+        type: 'string',
+        description: 'Short description shown in the block picker, max 280 characters',
+      },
+      exposedOutputs: {
+        type: 'array',
+        description:
+          "Outputs the block exposes, each mapping a child block output path to a friendly name (use get_block_outputs for valid paths). Omit to expose the terminal block's whole result",
+        items: {
+          type: 'object',
+          properties: {
+            blockId: { type: 'string', description: 'Block UUID inside the workflow' },
+            name: { type: 'string', description: 'Friendly output name shown on the block' },
+            path: {
+              type: 'string',
+              description:
+                "Dot-path into that block's output (from get_block_outputs relativeOutputs)",
+            },
+          },
+          required: ['blockId', 'path', 'name'],
+        },
+      },
+      iconUrl: {
+        type: 'string',
+        description:
+          'Optional icon image for the block: a workspace file VFS path (e.g. "files/icon.png", copied into public icon storage at publish) or an external image URL. Omit to use the organization\'s default icon',
+      },
+      inputs: {
+        type: 'array',
+        description:
+          "Optional per-input placeholder overrides. Input names and types are derived from the workflow's input trigger and cannot be changed here",
+        items: {
+          type: 'object',
+          properties: {
+            id: { type: 'string', description: 'Stable id of the input trigger field' },
+            placeholder: {
+              type: 'string',
+              description: "Placeholder text shown in the block's input field",
+            },
+          },
+          required: ['id'],
+        },
+      },
+      name: {
+        type: 'string',
+        description:
+          'Display name for the block, max 60 characters (required on first publish; defaults to the existing block name when republishing)',
+      },
+      workflowId: { type: 'string', description: 'Workflow ID (defaults to active workflow)' },
+    },
+  },
+  resultSchema: {
+    type: 'object',
+    properties: {
+      action: {
+        type: 'string',
+        description: 'Action performed by the tool, such as "deploy" or "undeploy".',
+      },
+      blockId: { type: 'string', description: 'Custom block record ID.' },
+      blockType: {
+        type: 'string',
+        description: 'Stable block type slug (custom_block_*) used in workflow state.',
+      },
+      deploymentConfig: {
+        type: 'object',
+        description:
+          "Structured deployment configuration keyed by surface name. Includes the block's type, name, description, icon, derived input fields, and exposed outputs.",
+      },
+      deploymentStatus: {
+        type: 'object',
+        description:
+          'Structured per-surface deployment status keyed by surface name, including customBlock and the underlying api surface when applicable.',
+      },
+      deploymentType: {
+        type: 'string',
+        description:
+          'Deployment surface this result describes. For deploy_custom_block this is always "custom_block".',
+      },
+      isDeployed: {
+        type: 'boolean',
+        description: 'Whether the custom block is published after this tool call.',
+      },
+      name: { type: 'string', description: 'Display name of the custom block.' },
+      removed: {
+        type: 'boolean',
+        description: 'Whether the custom block was unpublished during an undeploy action.',
+      },
+      updated: {
+        type: 'boolean',
+        description: 'Whether an existing custom block was updated instead of created.',
+      },
+      workflowId: { type: 'string', description: 'Workflow ID the custom block is bound to.' },
+    },
+    required: ['deploymentType', 'deploymentStatus'],
+  },
+  requiredPermission: 'admin',
+}
+
 export const DeployMcp: ToolCatalogEntry = {
   id: 'deploy_mcp',
   name: 'deploy_mcp',
@@ -4581,6 +4695,7 @@ export const TOOL_CATALOG: Record<string, ToolCatalogEntry> = {
   [Deploy.id]: Deploy,
   [DeployApi.id]: DeployApi,
   [DeployChat.id]: DeployChat,
+  [DeployCustomBlock.id]: DeployCustomBlock,
   [DeployMcp.id]: DeployMcp,
   [DiffWorkflows.id]: DiffWorkflows,
   [DownloadToWorkspaceFile.id]: DownloadToWorkspaceFile,
diff --git a/apps/sim/lib/copilot/generated/tool-schemas-v1.ts b/apps/sim/lib/copilot/generated/tool-schemas-v1.ts
index dcaea0db6ea..fcbf88408a6 100644
--- a/apps/sim/lib/copilot/generated/tool-schemas-v1.ts
+++ b/apps/sim/lib/copilot/generated/tool-schemas-v1.ts
@@ -10,7 +10,7 @@ export interface ToolRuntimeSchemaEntry {
 }
 
 export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
-  agent: {
+  ['agent']: {
     parameters: {
       properties: {
         request: {
@@ -23,7 +23,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  auth: {
+  ['auth']: {
     parameters: {
       properties: {
         request: {
@@ -36,7 +36,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  check_deployment_status: {
+  ['check_deployment_status']: {
     parameters: {
       type: 'object',
       properties: {
@@ -48,7 +48,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  complete_scheduled_task: {
+  ['complete_scheduled_task']: {
     parameters: {
       type: 'object',
       properties: {
@@ -61,7 +61,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  crawl_website: {
+  ['crawl_website']: {
     parameters: {
       type: 'object',
       properties: {
@@ -96,7 +96,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  create_file: {
+  ['create_file']: {
     parameters: {
       type: 'object',
       properties: {
@@ -162,7 +162,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
       required: ['success', 'message'],
     },
   },
-  create_file_folder: {
+  ['create_file_folder']: {
     parameters: {
       type: 'object',
       properties: {
@@ -180,7 +180,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  create_workflow: {
+  ['create_workflow']: {
     parameters: {
       type: 'object',
       properties: {
@@ -205,7 +205,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  create_workspace_mcp_server: {
+  ['create_workspace_mcp_server']: {
     parameters: {
       type: 'object',
       properties: {
@@ -238,7 +238,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  delete_file: {
+  ['delete_file']: {
     parameters: {
       type: 'object',
       properties: {
@@ -268,7 +268,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
       required: ['success', 'message'],
     },
   },
-  delete_file_folder: {
+  ['delete_file_folder']: {
     parameters: {
       type: 'object',
       properties: {
@@ -284,7 +284,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  delete_workflow: {
+  ['delete_workflow']: {
     parameters: {
       type: 'object',
       properties: {
@@ -300,7 +300,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  delete_workspace_mcp_server: {
+  ['delete_workspace_mcp_server']: {
     parameters: {
       type: 'object',
       properties: {
@@ -313,12 +313,12 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  deploy: {
+  ['deploy']: {
     parameters: {
       properties: {
         request: {
           description:
-            'Detailed deployment instructions. Include deployment type (api/chat/mcp) and ALL user-specified options: identifier, title, description, authType, password, allowedEmails, welcomeMessage, outputConfigs (block outputs to display).',
+            'Detailed deployment instructions. Include the deployment type and ALL user-specified options: identifier, title, description, authType, password, allowedEmails, welcomeMessage, outputConfigs (block outputs to display).',
           type: 'string',
         },
       },
@@ -327,7 +327,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  deploy_api: {
+  ['deploy_api']: {
     parameters: {
       type: 'object',
       properties: {
@@ -411,7 +411,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
       ],
     },
   },
-  deploy_chat: {
+  ['deploy_chat']: {
     parameters: {
       type: 'object',
       properties: {
@@ -570,7 +570,134 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
       ],
     },
   },
-  deploy_mcp: {
+  ['deploy_custom_block']: {
+    parameters: {
+      type: 'object',
+      properties: {
+        action: {
+          type: 'string',
+          description: 'Whether to publish (deploy) or unpublish (undeploy) the custom block',
+          enum: ['deploy', 'undeploy'],
+          default: 'deploy',
+        },
+        description: {
+          type: 'string',
+          description: 'Short description shown in the block picker, max 280 characters',
+        },
+        exposedOutputs: {
+          type: 'array',
+          description:
+            "Outputs the block exposes, each mapping a child block output path to a friendly name (use get_block_outputs for valid paths). Omit to expose the terminal block's whole result",
+          items: {
+            type: 'object',
+            properties: {
+              blockId: {
+                type: 'string',
+                description: 'Block UUID inside the workflow',
+              },
+              name: {
+                type: 'string',
+                description: 'Friendly output name shown on the block',
+              },
+              path: {
+                type: 'string',
+                description:
+                  "Dot-path into that block's output (from get_block_outputs relativeOutputs)",
+              },
+            },
+            required: ['blockId', 'path', 'name'],
+          },
+        },
+        iconUrl: {
+          type: 'string',
+          description:
+            'Optional icon image for the block: a workspace file VFS path (e.g. "files/icon.png", copied into public icon storage at publish) or an external image URL. Omit to use the organization\'s default icon',
+        },
+        inputs: {
+          type: 'array',
+          description:
+            "Optional per-input placeholder overrides. Input names and types are derived from the workflow's input trigger and cannot be changed here",
+          items: {
+            type: 'object',
+            properties: {
+              id: {
+                type: 'string',
+                description: 'Stable id of the input trigger field',
+              },
+              placeholder: {
+                type: 'string',
+                description: "Placeholder text shown in the block's input field",
+              },
+            },
+            required: ['id'],
+          },
+        },
+        name: {
+          type: 'string',
+          description:
+            'Display name for the block, max 60 characters (required on first publish; defaults to the existing block name when republishing)',
+        },
+        workflowId: {
+          type: 'string',
+          description: 'Workflow ID (defaults to active workflow)',
+        },
+      },
+    },
+    resultSchema: {
+      type: 'object',
+      properties: {
+        action: {
+          type: 'string',
+          description: 'Action performed by the tool, such as "deploy" or "undeploy".',
+        },
+        blockId: {
+          type: 'string',
+          description: 'Custom block record ID.',
+        },
+        blockType: {
+          type: 'string',
+          description: 'Stable block type slug (custom_block_*) used in workflow state.',
+        },
+        deploymentConfig: {
+          type: 'object',
+          description:
+            "Structured deployment configuration keyed by surface name. Includes the block's type, name, description, icon, derived input fields, and exposed outputs.",
+        },
+        deploymentStatus: {
+          type: 'object',
+          description:
+            'Structured per-surface deployment status keyed by surface name, including customBlock and the underlying api surface when applicable.',
+        },
+        deploymentType: {
+          type: 'string',
+          description:
+            'Deployment surface this result describes. For deploy_custom_block this is always "custom_block".',
+        },
+        isDeployed: {
+          type: 'boolean',
+          description: 'Whether the custom block is published after this tool call.',
+        },
+        name: {
+          type: 'string',
+          description: 'Display name of the custom block.',
+        },
+        removed: {
+          type: 'boolean',
+          description: 'Whether the custom block was unpublished during an undeploy action.',
+        },
+        updated: {
+          type: 'boolean',
+          description: 'Whether an existing custom block was updated instead of created.',
+        },
+        workflowId: {
+          type: 'string',
+          description: 'Workflow ID the custom block is bound to.',
+        },
+      },
+      required: ['deploymentType', 'deploymentStatus'],
+    },
+  },
+  ['deploy_mcp']: {
     parameters: {
       type: 'object',
       properties: {
@@ -686,7 +813,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
       required: ['deploymentType', 'deploymentStatus'],
     },
   },
-  diff_workflows: {
+  ['diff_workflows']: {
     parameters: {
       type: 'object',
       properties: {
@@ -710,7 +837,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  download_to_workspace_file: {
+  ['download_to_workspace_file']: {
     parameters: {
       type: 'object',
       properties: {
@@ -759,7 +886,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  edit_content: {
+  ['edit_content']: {
     parameters: {
       type: 'object',
       properties: {
@@ -791,7 +918,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
       required: ['success', 'message'],
     },
   },
-  edit_workflow: {
+  ['edit_workflow']: {
     parameters: {
       type: 'object',
       properties: {
@@ -830,7 +957,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  enrichment_run: {
+  ['enrichment_run']: {
     parameters: {
       type: 'object',
       properties: {
@@ -874,7 +1001,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
       required: ['matched', 'result'],
     },
   },
-  ffmpeg: {
+  ['ffmpeg']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1055,7 +1182,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  file: {
+  ['file']: {
     parameters: {
       properties: {
         prompt: {
@@ -1068,7 +1195,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  function_execute: {
+  ['function_execute']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1206,7 +1333,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  generate_api_key: {
+  ['generate_api_key']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1224,7 +1351,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  generate_audio: {
+  ['generate_audio']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1376,7 +1503,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  generate_image: {
+  ['generate_image']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1504,7 +1631,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  generate_video: {
+  ['generate_video']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1671,7 +1798,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  get_block_outputs: {
+  ['get_block_outputs']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1692,7 +1819,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  get_block_upstream_references: {
+  ['get_block_upstream_references']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1714,7 +1841,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  get_deployed_workflow_state: {
+  ['get_deployed_workflow_state']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1727,7 +1854,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  get_deployment_log: {
+  ['get_deployment_log']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1740,7 +1867,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  get_page_contents: {
+  ['get_page_contents']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1768,14 +1895,14 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  get_platform_actions: {
+  ['get_platform_actions']: {
     parameters: {
       type: 'object',
       properties: {},
     },
     resultSchema: undefined,
   },
-  get_scheduled_task_logs: {
+  ['get_scheduled_task_logs']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1800,7 +1927,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  get_workflow_data: {
+  ['get_workflow_data']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1819,7 +1946,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  get_workflow_run_options: {
+  ['get_workflow_run_options']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1832,7 +1959,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  glob: {
+  ['glob']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1851,7 +1978,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  grep: {
+  ['grep']: {
     parameters: {
       type: 'object',
       properties: {
@@ -1899,7 +2026,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  knowledge: {
+  ['knowledge']: {
     parameters: {
       properties: {
         request: {
@@ -1912,7 +2039,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  knowledge_base: {
+  ['knowledge_base']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2105,7 +2232,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
       required: ['success', 'message'],
     },
   },
-  list_file_folders: {
+  ['list_file_folders']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2117,7 +2244,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  list_integration_tools: {
+  ['list_integration_tools']: {
     parameters: {
       properties: {
         integration: {
@@ -2131,14 +2258,14 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  list_user_workspaces: {
+  ['list_user_workspaces']: {
     parameters: {
       type: 'object',
       properties: {},
     },
     resultSchema: undefined,
   },
-  list_workspace_mcp_servers: {
+  ['list_workspace_mcp_servers']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2151,7 +2278,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  load_deployment: {
+  ['load_deployment']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2170,7 +2297,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  load_integration_tool: {
+  ['load_integration_tool']: {
     parameters: {
       properties: {
         tool_ids: {
@@ -2187,7 +2314,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  manage_credential: {
+  ['manage_credential']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2216,7 +2343,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  manage_custom_tool: {
+  ['manage_custom_tool']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2296,7 +2423,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  manage_folder: {
+  ['manage_folder']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2335,7 +2462,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  manage_mcp_tool: {
+  ['manage_mcp_tool']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2387,7 +2514,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  manage_scheduled_task: {
+  ['manage_scheduled_task']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2462,7 +2589,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  manage_skill: {
+  ['manage_skill']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2495,7 +2622,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  materialize_file: {
+  ['materialize_file']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2519,7 +2646,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  media: {
+  ['media']: {
     parameters: {
       properties: {
         prompt: {
@@ -2532,7 +2659,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  move_file: {
+  ['move_file']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2553,7 +2680,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  move_file_folder: {
+  ['move_file_folder']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2571,7 +2698,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  move_workflow: {
+  ['move_workflow']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2591,7 +2718,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  oauth_get_auth_link: {
+  ['oauth_get_auth_link']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2605,7 +2732,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  oauth_request_access: {
+  ['oauth_request_access']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2619,7 +2746,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  open_resource: {
+  ['open_resource']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2653,7 +2780,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  promote_to_live: {
+  ['promote_to_live']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2672,7 +2799,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  query_logs: {
+  ['query_logs']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2783,7 +2910,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  read: {
+  ['read']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2810,7 +2937,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  redeploy: {
+  ['redeploy']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2889,7 +3016,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
       ],
     },
   },
-  rename_file: {
+  ['rename_file']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2925,7 +3052,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
       required: ['success', 'message'],
     },
   },
-  rename_file_folder: {
+  ['rename_file_folder']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2942,7 +3069,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  rename_workflow: {
+  ['rename_workflow']: {
     parameters: {
       type: 'object',
       properties: {
@@ -2959,7 +3086,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  research: {
+  ['research']: {
     parameters: {
       properties: {
         topic: {
@@ -2972,7 +3099,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  respond: {
+  ['respond']: {
     parameters: {
       additionalProperties: true,
       properties: {
@@ -2995,7 +3122,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  restore_resource: {
+  ['restore_resource']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3013,7 +3140,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  run: {
+  ['run']: {
     parameters: {
       properties: {
         context: {
@@ -3030,7 +3157,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  run_block: {
+  ['run_block']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3062,7 +3189,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  run_from_block: {
+  ['run_from_block']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3094,7 +3221,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  run_workflow: {
+  ['run_workflow']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3132,7 +3259,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  run_workflow_until_block: {
+  ['run_workflow_until_block']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3175,7 +3302,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  scheduled_task: {
+  ['scheduled_task']: {
     parameters: {
       properties: {
         request: {
@@ -3188,7 +3315,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  scrape_page: {
+  ['scrape_page']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3209,7 +3336,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  search_documentation: {
+  ['search_documentation']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3226,7 +3353,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  search_library_docs: {
+  ['search_library_docs']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3247,7 +3374,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  search_online: {
+  ['search_online']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3287,7 +3414,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  search_patterns: {
+  ['search_patterns']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3309,7 +3436,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  set_block_enabled: {
+  ['set_block_enabled']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3331,7 +3458,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  set_environment_variables: {
+  ['set_environment_variables']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3365,7 +3492,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  set_global_workflow_variables: {
+  ['set_global_workflow_variables']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3406,7 +3533,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  superagent: {
+  ['superagent']: {
     parameters: {
       properties: {
         task: {
@@ -3420,7 +3547,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  table: {
+  ['table']: {
     parameters: {
       properties: {
         request: {
@@ -3433,7 +3560,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  update_deployment_version: {
+  ['update_deployment_version']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3462,7 +3589,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  update_scheduled_task_history: {
+  ['update_scheduled_task_history']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3480,7 +3607,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  update_workspace_mcp_server: {
+  ['update_workspace_mcp_server']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3505,7 +3632,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  user_memory: {
+  ['user_memory']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3554,7 +3681,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  user_table: {
+  ['user_table']: {
     parameters: {
       type: 'object',
       properties: {
@@ -3917,7 +4044,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
       required: ['success', 'message'],
     },
   },
-  workflow: {
+  ['workflow']: {
     parameters: {
       properties: {
         prompt: {
@@ -3930,7 +4057,7 @@ export const TOOL_RUNTIME_SCHEMAS: Record<string, ToolRuntimeSchemaEntry> = {
     },
     resultSchema: undefined,
   },
-  workspace_file: {
+  ['workspace_file']: {
     parameters: {
       type: 'object',
       properties: {
diff --git a/apps/sim/lib/copilot/tool-executor/register-handlers.ts b/apps/sim/lib/copilot/tool-executor/register-handlers.ts
index b39027e3526..999dea91b28 100644
--- a/apps/sim/lib/copilot/tool-executor/register-handlers.ts
+++ b/apps/sim/lib/copilot/tool-executor/register-handlers.ts
@@ -8,6 +8,7 @@ import {
   DeleteWorkspaceMcpServer,
   DeployApi,
   DeployChat,
+  DeployCustomBlock,
   DeployMcp,
   DiffWorkflows,
   FunctionExecute,
@@ -53,6 +54,7 @@ import {
 } from '@/lib/copilot/generated/tool-catalog-v1'
 import { createServerToolHandler } from '@/lib/copilot/tools/registry/server-tool-adapter'
 import { getRegisteredServerToolNames } from '@/lib/copilot/tools/server/router'
+import { executeDeployCustomBlock } from '../tools/handlers/deployment/custom-block'
 import {
   executeDeployApi,
   executeDeployChat,
@@ -156,6 +158,7 @@ function buildHandlerMap(): Record<string, ToolHandler> {
     [DeployApi.id]: h(executeDeployApi),
     [DeployChat.id]: h(executeDeployChat),
     [DeployMcp.id]: h(executeDeployMcp),
+    [DeployCustomBlock.id]: h(executeDeployCustomBlock),
     [Redeploy.id]: h(executeRedeploy),
     [CheckDeploymentStatus.id]: h(executeCheckDeploymentStatus),
     [ListWorkspaceMcpServers.id]: h(executeListWorkspaceMcpServers),
diff --git a/apps/sim/lib/copilot/tools/handlers/deployment/custom-block.test.ts b/apps/sim/lib/copilot/tools/handlers/deployment/custom-block.test.ts
new file mode 100644
index 00000000000..b5e8850c279
--- /dev/null
+++ b/apps/sim/lib/copilot/tools/handlers/deployment/custom-block.test.ts
@@ -0,0 +1,414 @@
+/**
+ * @vitest-environment node
+ */
+
+import { auditMock } from '@sim/testing'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import type { ExecutionContext } from '@/lib/copilot/request/types'
+
+const {
+  ensureWorkflowAccessMock,
+  getWorkspaceWithOwnerMock,
+  isFeatureEnabledMock,
+  isOrganizationOnEnterprisePlanMock,
+  publishCustomBlockMock,
+  updateCustomBlockMock,
+  deleteCustomBlockMock,
+  getCustomBlockWithInputsByWorkflowIdMock,
+  listWorkspaceFilesMock,
+  fetchWorkspaceFileBufferMock,
+  uploadFileMock,
+} = vi.hoisted(() => ({
+  ensureWorkflowAccessMock: vi.fn(),
+  getWorkspaceWithOwnerMock: vi.fn(),
+  isFeatureEnabledMock: vi.fn(),
+  isOrganizationOnEnterprisePlanMock: vi.fn(),
+  publishCustomBlockMock: vi.fn(),
+  updateCustomBlockMock: vi.fn(),
+  deleteCustomBlockMock: vi.fn(),
+  getCustomBlockWithInputsByWorkflowIdMock: vi.fn(),
+  listWorkspaceFilesMock: vi.fn(),
+  fetchWorkspaceFileBufferMock: vi.fn(),
+  uploadFileMock: vi.fn(),
+}))
+
+vi.mock('@sim/audit', () => auditMock)
+
+vi.mock('../access', () => ({
+  ensureWorkflowAccess: ensureWorkflowAccessMock,
+  ensureWorkspaceAccess: vi.fn(),
+}))
+
+vi.mock('@/lib/workspaces/permissions/utils', () => ({
+  getWorkspaceWithOwner: getWorkspaceWithOwnerMock,
+}))
+
+vi.mock('@/lib/core/config/feature-flags', () => ({
+  isFeatureEnabled: isFeatureEnabledMock,
+}))
+
+vi.mock('@/lib/billing', () => ({
+  isOrganizationOnEnterprisePlan: isOrganizationOnEnterprisePlanMock,
+}))
+
+vi.mock('@/lib/uploads/contexts/workspace/workspace-file-manager', () => ({
+  listWorkspaceFiles: listWorkspaceFilesMock,
+  fetchWorkspaceFileBuffer: fetchWorkspaceFileBufferMock,
+}))
+
+vi.mock('@/lib/uploads/core/storage-service', () => ({
+  uploadFile: uploadFileMock,
+}))
+
+vi.mock('@/lib/uploads/utils/file-utils', () => ({
+  isImageFileType: (type: string) => type.startsWith('image/'),
+}))
+
+vi.mock('@/lib/workflows/custom-blocks/operations', () => {
+  class CustomBlockValidationError extends Error {}
+  return {
+    CustomBlockValidationError,
+    publishCustomBlock: publishCustomBlockMock,
+    updateCustomBlock: updateCustomBlockMock,
+    deleteCustomBlock: deleteCustomBlockMock,
+    getCustomBlockWithInputsByWorkflowId: getCustomBlockWithInputsByWorkflowIdMock,
+  }
+})
+
+import { executeDeployCustomBlock } from './custom-block'
+
+const context = { userId: 'user-1', workflowId: 'wf-1' } as ExecutionContext
+
+const publishedBlock = {
+  id: 'cb-1',
+  organizationId: 'org-1',
+  workflowId: 'wf-1',
+  workflowName: 'Test Workflow',
+  workspaceId: 'ws-1',
+  workspaceName: 'Workspace',
+  type: 'custom_block_abc123',
+  name: 'Enrich Lead',
+  description: 'Enrich a lead by email',
+  iconUrl: null,
+  enabled: true,
+  inputFields: [{ id: 'f1', name: 'email', type: 'string' }],
+  exposedOutputs: [{ blockId: 'b1', path: 'content', name: 'summary' }],
+}
+
+describe('executeDeployCustomBlock', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    ensureWorkflowAccessMock.mockResolvedValue({
+      workflow: { id: 'wf-1', workspaceId: 'ws-1', name: 'Test Workflow', isDeployed: true },
+    })
+    getWorkspaceWithOwnerMock.mockResolvedValue({ id: 'ws-1', organizationId: 'org-1' })
+    isFeatureEnabledMock.mockResolvedValue(true)
+    isOrganizationOnEnterprisePlanMock.mockResolvedValue(true)
+    getCustomBlockWithInputsByWorkflowIdMock.mockResolvedValue(null)
+  })
+
+  it('publishes a new custom block', async () => {
+    publishCustomBlockMock.mockResolvedValue(publishedBlock)
+
+    const result = await executeDeployCustomBlock(
+      {
+        name: 'Enrich Lead',
+        description: 'Enrich a lead by email',
+        exposedOutputs: [{ blockId: 'b1', path: 'content', name: 'summary' }],
+      },
+      context
+    )
+
+    expect(ensureWorkflowAccessMock).toHaveBeenCalledWith('wf-1', 'user-1', 'admin')
+    expect(publishCustomBlockMock).toHaveBeenCalledWith({
+      organizationId: 'org-1',
+      workspaceId: 'ws-1',
+      workflowId: 'wf-1',
+      userId: 'user-1',
+      name: 'Enrich Lead',
+      description: 'Enrich a lead by email',
+      iconUrl: undefined,
+      inputs: undefined,
+      exposedOutputs: [{ blockId: 'b1', path: 'content', name: 'summary' }],
+    })
+    expect(result.success).toBe(true)
+    expect(result.output).toMatchObject({
+      workflowId: 'wf-1',
+      blockType: 'custom_block_abc123',
+      isDeployed: true,
+      updated: false,
+      deploymentType: 'custom_block',
+      deploymentStatus: { customBlock: { isDeployed: true, name: 'Enrich Lead' } },
+    })
+  })
+
+  it('returns a clean admin-permission error when workflow access is denied', async () => {
+    ensureWorkflowAccessMock.mockRejectedValue(new Error('Unauthorized workflow access'))
+
+    const result = await executeDeployCustomBlock({ name: 'Enrich Lead' }, context)
+
+    expect(result.success).toBe(false)
+    expect(result.error).toContain('admin permission')
+    expect(publishCustomBlockMock).not.toHaveBeenCalled()
+  })
+
+  it('surfaces workflow-not-found from access resolution', async () => {
+    ensureWorkflowAccessMock.mockRejectedValue(new Error('Workflow wf-1 not found'))
+
+    const result = await executeDeployCustomBlock({ name: 'Enrich Lead' }, context)
+
+    expect(result.success).toBe(false)
+    expect(result.error).toContain('not found')
+  })
+
+  it('requires a name on first publish', async () => {
+    const result = await executeDeployCustomBlock({}, context)
+
+    expect(result.success).toBe(false)
+    expect(result.error).toContain('name is required')
+    expect(publishCustomBlockMock).not.toHaveBeenCalled()
+  })
+
+  it('requires the workflow to be deployed on first publish', async () => {
+    ensureWorkflowAccessMock.mockResolvedValue({
+      workflow: { id: 'wf-1', workspaceId: 'ws-1', name: 'Test Workflow', isDeployed: false },
+    })
+
+    const result = await executeDeployCustomBlock({ name: 'Enrich Lead' }, context)
+
+    expect(result.success).toBe(false)
+    expect(result.error).toContain('deploy_api')
+    expect(publishCustomBlockMock).not.toHaveBeenCalled()
+  })
+
+  it('updates an existing block in place', async () => {
+    getCustomBlockWithInputsByWorkflowIdMock
+      .mockResolvedValueOnce(publishedBlock)
+      .mockResolvedValueOnce({ ...publishedBlock, name: 'Enrich Lead v2' })
+
+    const result = await executeDeployCustomBlock({ name: 'Enrich Lead v2' }, context)
+
+    expect(updateCustomBlockMock).toHaveBeenCalledWith('cb-1', {
+      name: 'Enrich Lead v2',
+      description: undefined,
+      iconUrl: undefined,
+      inputs: undefined,
+      exposedOutputs: undefined,
+    })
+    expect(publishCustomBlockMock).not.toHaveBeenCalled()
+    expect(result.success).toBe(true)
+    expect(result.output).toMatchObject({ updated: true, name: 'Enrich Lead v2' })
+  })
+
+  it('unpublishes the block on undeploy', async () => {
+    getCustomBlockWithInputsByWorkflowIdMock.mockResolvedValue(publishedBlock)
+
+    const result = await executeDeployCustomBlock({ action: 'undeploy' }, context)
+
+    expect(deleteCustomBlockMock).toHaveBeenCalledWith('cb-1')
+    expect(result.success).toBe(true)
+    expect(result.output).toMatchObject({
+      isDeployed: false,
+      removed: true,
+      action: 'undeploy',
+      blockType: 'custom_block_abc123',
+    })
+  })
+
+  it('updates an existing block without requiring the enterprise plan', async () => {
+    isOrganizationOnEnterprisePlanMock.mockResolvedValue(false)
+    getCustomBlockWithInputsByWorkflowIdMock
+      .mockResolvedValueOnce(publishedBlock)
+      .mockResolvedValueOnce(publishedBlock)
+
+    const result = await executeDeployCustomBlock({ description: 'refreshed copy' }, context)
+
+    expect(result.success).toBe(true)
+    expect(updateCustomBlockMock).toHaveBeenCalled()
+    expect(publishCustomBlockMock).not.toHaveBeenCalled()
+  })
+
+  it('undeploys without requiring the enterprise plan', async () => {
+    isOrganizationOnEnterprisePlanMock.mockResolvedValue(false)
+    getCustomBlockWithInputsByWorkflowIdMock.mockResolvedValue(publishedBlock)
+
+    const result = await executeDeployCustomBlock({ action: 'undeploy' }, context)
+
+    expect(result.success).toBe(true)
+    expect(deleteCustomBlockMock).toHaveBeenCalledWith('cb-1')
+  })
+
+  it('does not clear the stored name when a republish sends whitespace', async () => {
+    getCustomBlockWithInputsByWorkflowIdMock
+      .mockResolvedValueOnce(publishedBlock)
+      .mockResolvedValueOnce(publishedBlock)
+
+    const result = await executeDeployCustomBlock({ name: '   ' }, context)
+
+    expect(updateCustomBlockMock).toHaveBeenCalledWith(
+      'cb-1',
+      expect.objectContaining({ name: undefined })
+    )
+    expect(result.success).toBe(true)
+  })
+
+  it('rejects oversized exposedOutputs and inputs arrays', async () => {
+    const outputs = Array.from({ length: 51 }, (_, i) => ({
+      blockId: `b${i}`,
+      path: 'content',
+      name: `out${i}`,
+    }))
+    const tooManyOutputs = await executeDeployCustomBlock(
+      { name: 'Enrich Lead', exposedOutputs: outputs },
+      context
+    )
+    expect(tooManyOutputs.success).toBe(false)
+    expect(tooManyOutputs.error).toContain('50')
+
+    const inputs = Array.from({ length: 51 }, (_, i) => ({ id: `f${i}` }))
+    const tooManyInputs = await executeDeployCustomBlock({ name: 'Enrich Lead', inputs }, context)
+    expect(tooManyInputs.success).toBe(false)
+    expect(tooManyInputs.error).toContain('50')
+    expect(publishCustomBlockMock).not.toHaveBeenCalled()
+  })
+
+  it('rejects oversized per-item fields', async () => {
+    const longPlaceholder = await executeDeployCustomBlock(
+      { name: 'Enrich Lead', inputs: [{ id: 'f1', placeholder: 'x'.repeat(201) }] },
+      context
+    )
+    expect(longPlaceholder.success).toBe(false)
+    expect(longPlaceholder.error).toContain('200')
+
+    const longOutputName = await executeDeployCustomBlock(
+      {
+        name: 'Enrich Lead',
+        exposedOutputs: [{ blockId: 'b1', path: 'content', name: 'x'.repeat(61) }],
+      },
+      context
+    )
+    expect(longOutputName.success).toBe(false)
+    expect(longOutputName.error).toContain('60')
+    expect(publishCustomBlockMock).not.toHaveBeenCalled()
+  })
+
+  it('rejects exposedOutputs entries missing required fields', async () => {
+    const result = await executeDeployCustomBlock(
+      { name: 'Enrich Lead', exposedOutputs: [{ blockId: 'b1', path: '', name: 'out' }] },
+      context
+    )
+    expect(result.success).toBe(false)
+    expect(result.error).toContain('blockId, path, and name')
+  })
+
+  it('fails undeploy when the workflow is not published as a block', async () => {
+    const result = await executeDeployCustomBlock({ action: 'undeploy' }, context)
+
+    expect(result.success).toBe(false)
+    expect(deleteCustomBlockMock).not.toHaveBeenCalled()
+  })
+
+  it('fails when the feature flag is off', async () => {
+    isFeatureEnabledMock.mockResolvedValue(false)
+
+    const result = await executeDeployCustomBlock({ name: 'Enrich Lead' }, context)
+
+    expect(result.success).toBe(false)
+    expect(result.error).toContain('not enabled')
+  })
+
+  it('fails when the org is not on the enterprise plan', async () => {
+    isOrganizationOnEnterprisePlanMock.mockResolvedValue(false)
+
+    const result = await executeDeployCustomBlock({ name: 'Enrich Lead' }, context)
+
+    expect(result.success).toBe(false)
+    expect(result.error).toContain('enterprise')
+  })
+
+  it('ingests a workspace-file icon into public icon storage', async () => {
+    listWorkspaceFilesMock.mockResolvedValue([
+      {
+        name: 'icon.png',
+        folderPath: null,
+        type: 'image/png',
+        size: 1024,
+        key: 'workspace/ws-1/123-abc-icon.png',
+      },
+    ])
+    fetchWorkspaceFileBufferMock.mockResolvedValue(Buffer.from('png-bytes'))
+    uploadFileMock.mockResolvedValue({ path: '/api/files/serve/s3/workspace-logos%2Ficon.png' })
+    publishCustomBlockMock.mockResolvedValue(publishedBlock)
+
+    const result = await executeDeployCustomBlock(
+      { name: 'Enrich Lead', iconUrl: 'files/icon.png' },
+      context
+    )
+
+    expect(uploadFileMock).toHaveBeenCalledWith(
+      expect.objectContaining({
+        context: 'workspace-logos',
+        contentType: 'image/png',
+        customKey: expect.stringMatching(/^workspace-logos\/\d+-[A-Za-z0-9_-]+-icon\.png$/),
+        preserveKey: true,
+        metadata: { workspaceId: 'ws-1', userId: 'user-1', originalName: 'icon.png' },
+      })
+    )
+    expect(publishCustomBlockMock).toHaveBeenCalledWith(
+      expect.objectContaining({ iconUrl: '/api/files/serve/s3/workspace-logos%2Ficon.png' })
+    )
+    expect(result.success).toBe(true)
+  })
+
+  it('passes an external icon URL through without ingestion', async () => {
+    publishCustomBlockMock.mockResolvedValue(publishedBlock)
+
+    const result = await executeDeployCustomBlock(
+      { name: 'Enrich Lead', iconUrl: 'https://example.com/icon.png' },
+      context
+    )
+
+    expect(uploadFileMock).not.toHaveBeenCalled()
+    expect(publishCustomBlockMock).toHaveBeenCalledWith(
+      expect.objectContaining({ iconUrl: 'https://example.com/icon.png' })
+    )
+    expect(result.success).toBe(true)
+  })
+
+  it('fails when the icon workspace file does not exist', async () => {
+    listWorkspaceFilesMock.mockResolvedValue([])
+
+    const result = await executeDeployCustomBlock(
+      { name: 'Enrich Lead', iconUrl: 'files/missing.png' },
+      context
+    )
+
+    expect(result.success).toBe(false)
+    expect(result.error).toContain('not found')
+    expect(publishCustomBlockMock).not.toHaveBeenCalled()
+  })
+
+  it('fails when the icon workspace file is not an image', async () => {
+    listWorkspaceFilesMock.mockResolvedValue([
+      { name: 'notes.pdf', folderPath: null, type: 'application/pdf', size: 1024, key: 'k' },
+    ])
+
+    const result = await executeDeployCustomBlock(
+      { name: 'Enrich Lead', iconUrl: 'files/notes.pdf' },
+      context
+    )
+
+    expect(result.success).toBe(false)
+    expect(result.error).toContain('image')
+    expect(uploadFileMock).not.toHaveBeenCalled()
+  })
+
+  it('fails when the workspace has no organization', async () => {
+    getWorkspaceWithOwnerMock.mockResolvedValue({ id: 'ws-1', organizationId: null })
+
+    const result = await executeDeployCustomBlock({ name: 'Enrich Lead' }, context)
+
+    expect(result.success).toBe(false)
+    expect(result.error).toContain('organization')
+  })
+})
diff --git a/apps/sim/lib/copilot/tools/handlers/deployment/custom-block.ts b/apps/sim/lib/copilot/tools/handlers/deployment/custom-block.ts
new file mode 100644
index 00000000000..65d2bed86d6
--- /dev/null
+++ b/apps/sim/lib/copilot/tools/handlers/deployment/custom-block.ts
@@ -0,0 +1,281 @@
+import { AuditAction, AuditResourceType, recordAudit } from '@sim/audit'
+import { toError } from '@sim/utils/errors'
+import { generateShortId } from '@sim/utils/id'
+import { isOrganizationOnEnterprisePlan } from '@/lib/billing'
+import type { ExecutionContext, ToolCallResult } from '@/lib/copilot/request/types'
+import { canonicalizeVfsPath, canonicalWorkspaceFilePath } from '@/lib/copilot/vfs/path-utils'
+import { isFeatureEnabled } from '@/lib/core/config/feature-flags'
+import {
+  fetchWorkspaceFileBuffer,
+  listWorkspaceFiles,
+} from '@/lib/uploads/contexts/workspace/workspace-file-manager'
+import { uploadFile } from '@/lib/uploads/core/storage-service'
+import { isImageFileType } from '@/lib/uploads/utils/file-utils'
+import {
+  CustomBlockValidationError,
+  type CustomBlockWithInputs,
+  deleteCustomBlock,
+  getCustomBlockWithInputsByWorkflowId,
+  publishCustomBlock,
+  updateCustomBlock,
+} from '@/lib/workflows/custom-blocks/operations'
+import { getWorkspaceWithOwner } from '@/lib/workspaces/permissions/utils'
+import { ensureWorkflowAccess } from '../access'
+import type { DeployCustomBlockParams } from '../param-types'
+
+const MAX_ICON_BYTES = 5 * 1024 * 1024
+const MAX_INPUT_ENTRIES = 50
+const MAX_OUTPUT_ENTRIES = 50
+
+/**
+ * Resolve the agent-supplied icon reference to a publicly servable URL. A VFS
+ * workspace-file path (`files/...`) is ingested: the file is copied into the
+ * world-readable `workspace-logos` storage context (the same context the icon
+ * upload UI writes to), because a raw workspace-file URL is membership-gated
+ * and the block's icon must render for org members in other workspaces. Any
+ * other non-empty value (an external or already-public URL) passes through.
+ */
+async function resolveIconUrl(
+  raw: string | undefined,
+  userId: string,
+  workspaceId: string
+): Promise<string | undefined> {
+  const value = raw?.trim()
+  if (!value) return undefined
+  if (!value.startsWith('files/')) return value
+
+  const canonical = canonicalizeVfsPath(value)
+  const files = await listWorkspaceFiles(workspaceId, { hydrateFolderPaths: true })
+  const record = files.find(
+    (f) => canonicalWorkspaceFilePath({ folderPath: f.folderPath, name: f.name }) === canonical
+  )
+  if (!record) {
+    throw new CustomBlockValidationError(`Icon file not found in this workspace: ${value}`)
+  }
+  if (!isImageFileType(record.type)) {
+    throw new CustomBlockValidationError(
+      'Icon file must be an image (PNG, JPEG, GIF, WebP, or SVG)'
+    )
+  }
+  if (record.size > MAX_ICON_BYTES) {
+    throw new CustomBlockValidationError('Icon file must be 5MB or smaller')
+  }
+
+  const buffer = await fetchWorkspaceFileBuffer(record)
+  const safeFileName = record.name.replace(/[^a-zA-Z0-9.-]/g, '_')
+  const uploaded = await uploadFile({
+    file: buffer,
+    fileName: record.name,
+    contentType: record.type,
+    context: 'workspace-logos',
+    customKey: `workspace-logos/${Date.now()}-${generateShortId()}-${safeFileName}`,
+    preserveKey: true,
+    metadata: { workspaceId, userId, originalName: record.name },
+  })
+  return uploaded.path
+}
+
+function customBlockOutput(block: CustomBlockWithInputs, action: 'deploy' | 'undeploy') {
+  const isDeployed = action === 'deploy'
+  return {
+    workflowId: block.workflowId,
+    blockId: block.id,
+    blockType: block.type,
+    name: block.name,
+    action,
+    isDeployed,
+    removed: !isDeployed,
+    deploymentType: 'custom_block',
+    deploymentStatus: {
+      customBlock: {
+        isDeployed,
+        blockType: block.type,
+        name: block.name,
+        enabled: block.enabled,
+      },
+    },
+    deploymentConfig: {
+      customBlock: {
+        blockType: block.type,
+        name: block.name,
+        description: block.description,
+        iconUrl: block.iconUrl,
+        inputFields: block.inputFields,
+        exposedOutputs: block.exposedOutputs,
+        organizationId: block.organizationId,
+      },
+    },
+  }
+}
+
+export async function executeDeployCustomBlock(
+  params: DeployCustomBlockParams,
+  context: ExecutionContext
+): Promise<ToolCallResult> {
+  try {
+    const workflowId = params.workflowId || context.workflowId
+    if (!workflowId) {
+      return { success: false, error: 'workflowId is required' }
+    }
+    const action = params.action === 'undeploy' ? 'undeploy' : 'deploy'
+
+    let workflowRecord: Awaited<ReturnType<typeof ensureWorkflowAccess>>['workflow']
+    try {
+      workflowRecord = (await ensureWorkflowAccess(workflowId, context.userId, 'admin')).workflow
+    } catch (error) {
+      const message = toError(error).message
+      if (message.includes('not found')) {
+        return { success: false, error: message }
+      }
+      return {
+        success: false,
+        error: "Managing a custom block requires admin permission on the workflow's workspace",
+      }
+    }
+    const workspaceId = workflowRecord.workspaceId
+    if (!workspaceId) {
+      return { success: false, error: 'Workflow must belong to a workspace' }
+    }
+
+    const ws = await getWorkspaceWithOwner(workspaceId)
+    const organizationId = ws?.organizationId
+    if (!organizationId) {
+      return {
+        success: false,
+        error: 'Publishing a block requires the workspace to belong to an organization',
+      }
+    }
+    if (
+      !(await isFeatureEnabled('deploy-as-block', {
+        userId: context.userId,
+        orgId: organizationId,
+      }))
+    ) {
+      return { success: false, error: 'Custom blocks are not enabled for this organization' }
+    }
+
+    const existing = await getCustomBlockWithInputsByWorkflowId(workflowId)
+
+    if (action === 'undeploy') {
+      if (!existing) {
+        return { success: false, error: 'This workflow is not published as a custom block' }
+      }
+      await deleteCustomBlock(existing.id)
+      recordAudit({
+        workspaceId,
+        actorId: context.userId,
+        action: AuditAction.CUSTOM_BLOCK_DELETED,
+        resourceType: AuditResourceType.CUSTOM_BLOCK,
+        resourceId: existing.id,
+        resourceName: existing.name,
+        description: `Unpublished custom block "${existing.name}"`,
+        metadata: { organizationId, type: existing.type, workflowId, source: 'copilot' },
+      })
+      return { success: true, output: customBlockOutput(existing, 'undeploy') }
+    }
+
+    const name = params.name?.trim()
+    const description = params.description?.trim()
+    if (name && name.length > 60) {
+      return { success: false, error: 'name must be 60 characters or fewer' }
+    }
+    if (description && description.length > 280) {
+      return { success: false, error: 'description must be 280 characters or fewer' }
+    }
+    if (params.inputs && params.inputs.length > MAX_INPUT_ENTRIES) {
+      return { success: false, error: `inputs must be ${MAX_INPUT_ENTRIES} entries or fewer` }
+    }
+    if (params.inputs?.some((entry) => !entry?.id?.trim())) {
+      return { success: false, error: 'each inputs entry requires the trigger field id' }
+    }
+    if (params.inputs?.some((entry) => (entry.placeholder?.length ?? 0) > 200)) {
+      return { success: false, error: 'input placeholders must be 200 characters or fewer' }
+    }
+    if (params.exposedOutputs && params.exposedOutputs.length > MAX_OUTPUT_ENTRIES) {
+      return {
+        success: false,
+        error: `exposedOutputs must be ${MAX_OUTPUT_ENTRIES} entries or fewer`,
+      }
+    }
+    if (
+      params.exposedOutputs?.some(
+        (entry) => !entry?.blockId?.trim() || !entry?.path?.trim() || !entry?.name?.trim()
+      )
+    ) {
+      return {
+        success: false,
+        error: 'each exposedOutputs entry requires blockId, path, and name',
+      }
+    }
+    if (params.exposedOutputs?.some((entry) => entry.name.length > 60)) {
+      return { success: false, error: 'exposed output names must be 60 characters or fewer' }
+    }
+    const iconUrl = await resolveIconUrl(params.iconUrl, context.userId, workspaceId)
+
+    if (existing) {
+      await updateCustomBlock(existing.id, {
+        name: name || undefined,
+        description,
+        iconUrl,
+        inputs: params.inputs,
+        exposedOutputs: params.exposedOutputs,
+      })
+      const updated = await getCustomBlockWithInputsByWorkflowId(workflowId)
+      if (!updated) {
+        return { success: false, error: 'Custom block not found after update' }
+      }
+      recordAudit({
+        workspaceId,
+        actorId: context.userId,
+        action: AuditAction.CUSTOM_BLOCK_UPDATED,
+        resourceType: AuditResourceType.CUSTOM_BLOCK,
+        resourceId: updated.id,
+        resourceName: updated.name,
+        description: `Updated custom block "${updated.name}"`,
+        metadata: { organizationId, type: updated.type, workflowId, source: 'copilot' },
+      })
+      return { success: true, output: { ...customBlockOutput(updated, 'deploy'), updated: true } }
+    }
+
+    if (!(await isOrganizationOnEnterprisePlan(organizationId))) {
+      return { success: false, error: 'Custom blocks require an enterprise plan' }
+    }
+    if (!name) {
+      return { success: false, error: 'name is required when publishing a new custom block' }
+    }
+    if (!workflowRecord.isDeployed) {
+      return {
+        success: false,
+        error:
+          'Workflow must be deployed before publishing as a custom block. Use deploy_api first.',
+      }
+    }
+    const block = await publishCustomBlock({
+      organizationId,
+      workspaceId,
+      workflowId,
+      userId: context.userId,
+      name,
+      description: description ?? '',
+      iconUrl,
+      inputs: params.inputs,
+      exposedOutputs: params.exposedOutputs,
+    })
+    recordAudit({
+      workspaceId,
+      actorId: context.userId,
+      action: AuditAction.CUSTOM_BLOCK_PUBLISHED,
+      resourceType: AuditResourceType.CUSTOM_BLOCK,
+      resourceId: block.id,
+      resourceName: block.name,
+      description: `Published custom block "${block.name}"`,
+      metadata: { organizationId, type: block.type, workflowId, source: 'copilot' },
+    })
+    return { success: true, output: { ...customBlockOutput(block, 'deploy'), updated: false } }
+  } catch (error) {
+    if (error instanceof CustomBlockValidationError) {
+      return { success: false, error: error.message }
+    }
+    return { success: false, error: toError(error).message }
+  }
+}
diff --git a/apps/sim/lib/copilot/tools/handlers/param-types.ts b/apps/sim/lib/copilot/tools/handlers/param-types.ts
index da437b4993a..19eae663ba8 100644
--- a/apps/sim/lib/copilot/tools/handlers/param-types.ts
+++ b/apps/sim/lib/copilot/tools/handlers/param-types.ts
@@ -173,6 +173,24 @@ export interface DeployMcpParams {
   parameterDescriptions?: Array<{ name: string; description: string }>
 }
 
+export interface DeployCustomBlockParams {
+  workflowId?: string
+  action?: 'deploy' | 'undeploy'
+  /** Block display name (max 60 chars). Required on first publish. */
+  name?: string
+  /** Block-picker description (max 280 chars). */
+  description?: string
+  /** Icon image URL; omit for the organization's default icon. */
+  iconUrl?: string
+  /**
+   * Per-input placeholder overrides keyed by the input trigger field's stable id.
+   * The field set itself is always derived from the workflow's deployment.
+   */
+  inputs?: Array<{ id: string; placeholder?: string }>
+  /** Curated outputs; omit to expose the terminal block's whole result. */
+  exposedOutputs?: Array<{ blockId: string; path: string; name: string }>
+}
+
 export interface CheckDeploymentStatusParams {
   workflowId?: string
 }
diff --git a/apps/sim/lib/mothership/inbox/executor.ts b/apps/sim/lib/mothership/inbox/executor.ts
index 86ac2312b2d..903018024d6 100644
--- a/apps/sim/lib/mothership/inbox/executor.ts
+++ b/apps/sim/lib/mothership/inbox/executor.ts
@@ -13,6 +13,7 @@ import {
 } from '@/lib/copilot/chat/persisted-message'
 import { generateWorkspaceContext } from '@/lib/copilot/chat/workspace-context'
 import { chatPubSub } from '@/lib/copilot/chat-status'
+import { computeWorkspaceEntitlements } from '@/lib/copilot/entitlements'
 import { runHeadlessCopilotLifecycle } from '@/lib/copilot/request/lifecycle/headless'
 import { requestChatTitle } from '@/lib/copilot/request/lifecycle/start'
 import type { OrchestratorResult } from '@/lib/copilot/request/types'
@@ -208,14 +209,21 @@ export async function executeInboxTask(taskId: string): Promise<void> {
       return { attachments, ...downloaded }
     }
 
-    const [attachmentResult, workspaceContext, integrationTools, userSkillTool, userPermission] =
-      await Promise.all([
-        fetchAttachments(),
-        generateWorkspaceContext(ws.id, userId),
-        buildIntegrationToolSchemas(userId, undefined, undefined, ws.id),
-        buildUserSkillTool(ws.id),
-        getUserEntityPermissions(userId, 'workspace', ws.id).catch(() => null),
-      ])
+    const [
+      attachmentResult,
+      workspaceContext,
+      integrationTools,
+      userSkillTool,
+      userPermission,
+      entitlements,
+    ] = await Promise.all([
+      fetchAttachments(),
+      generateWorkspaceContext(ws.id, userId),
+      buildIntegrationToolSchemas(userId, undefined, undefined, ws.id),
+      buildUserSkillTool(ws.id),
+      getUserEntityPermissions(userId, 'workspace', ws.id).catch(() => null),
+      computeWorkspaceEntitlements(ws.id, userId),
+    ])
     const { attachments, fileAttachments, storedAttachments } = attachmentResult
 
     const truncatedTask = {
@@ -237,6 +245,7 @@ export async function executeInboxTask(taskId: string): Promise<void> {
       ...(integrationTools.length > 0 ? { integrationTools } : {}),
       ...(userSkillTool ? { mothershipTools: [userSkillTool] } : {}),
       ...(userPermission ? { userPermission } : {}),
+      ...(entitlements.length > 0 ? { entitlements } : {}),
       ...(fileAttachments.length > 0 ? { fileAttachments } : {}),
     }
 
diff --git a/apps/sim/lib/workflows/custom-blocks/operations.ts b/apps/sim/lib/workflows/custom-blocks/operations.ts
index 28d7dc5af35..5e5786d68bb 100644
--- a/apps/sim/lib/workflows/custom-blocks/operations.ts
+++ b/apps/sim/lib/workflows/custom-blocks/operations.ts
@@ -19,15 +19,36 @@ const logger = createLogger('CustomBlocksOperations')
  * enterprise plan). Applying it in every org-scoped resolver keeps execution, the
  * copilot VFS, and workspace context from surfacing blocks the API withholds (e.g.
  * after an org drops off the enterprise plan). Returns `null` when ineligible.
+ *
+ * Pass `userId` when the caller acts for a specific user so per-user flag
+ * targeting matches the REST routes; workspace-scoped resolvers (VFS, context,
+ * executor overlay) omit it and evaluate at org level.
  */
-async function eligibleOrgForWorkspace(workspaceId: string): Promise<string | null> {
+async function eligibleOrgForWorkspace(
+  workspaceId: string,
+  userId?: string
+): Promise<string | null> {
   const ws = await getWorkspaceWithOwner(workspaceId, { includeArchived: true })
   if (!ws?.organizationId) return null
-  if (!(await isFeatureEnabled('deploy-as-block', { orgId: ws.organizationId }))) return null
+  if (!(await isFeatureEnabled('deploy-as-block', { userId, orgId: ws.organizationId }))) {
+    return null
+  }
   if (!(await isOrganizationOnEnterprisePlan(ws.organizationId))) return null
   return ws.organizationId
 }
 
+/**
+ * Whether the workspace's org may use custom blocks (`deploy-as-block` flag +
+ * enterprise plan). Feeds the 'custom-blocks' entitlement in
+ * `@/lib/copilot/entitlements` and matches the REST route gates.
+ */
+export async function isCustomBlocksEligible(
+  workspaceId: string,
+  userId?: string
+): Promise<boolean> {
+  return (await eligibleOrgForWorkspace(workspaceId, userId)) !== null
+}
+
 /** A persisted custom block plus its live-derived Start input fields. */
 export interface CustomBlockWithInputs {
   id: string
@@ -159,6 +180,37 @@ export async function listCustomBlockSummariesForWorkspace(
     .where(and(eq(customBlock.organizationId, organizationId), eq(customBlock.enabled, true)))
 }
 
+/**
+ * Hydrate a joined custom-block row into the wire shape. Field set derived live
+ * from the deployed Start; stored placeholders merged in. Derive even for a
+ * disabled block — the source workflow's deployment is independent of the block's
+ * enabled flag, and the edit form needs the real fields so a save doesn't
+ * overwrite the block's stored placeholders.
+ */
+async function hydrateCustomBlockRow(joined: {
+  block: typeof customBlock.$inferSelect
+  workflowName: string
+  workspaceId: string | null
+  workspaceName: string | null
+}): Promise<CustomBlockWithInputs> {
+  const { block: row, workflowName, workspaceId, workspaceName } = joined
+  return {
+    id: row.id,
+    organizationId: row.organizationId,
+    workflowId: row.workflowId,
+    workflowName,
+    workspaceId,
+    workspaceName,
+    type: row.type,
+    name: row.name,
+    description: row.description,
+    iconUrl: row.iconUrl,
+    enabled: row.enabled,
+    inputFields: applyInputPlaceholders(row.inputs, await deriveInputFields(row.workflowId)),
+    exposedOutputs: row.outputs ?? [],
+  }
+}
+
 /** The org's custom blocks with live-derived input fields (client overlay + list API). */
 export async function listCustomBlocksWithInputs(
   organizationId: string
@@ -175,27 +227,30 @@ export async function listCustomBlocksWithInputs(
     .leftJoin(workspace, eq(workspace.id, workflow.workspaceId))
     .where(eq(customBlock.organizationId, organizationId))
 
-  return Promise.all(
-    rows.map(async ({ block: row, workflowName, workspaceId, workspaceName }) => ({
-      id: row.id,
-      organizationId: row.organizationId,
-      workflowId: row.workflowId,
-      workflowName,
-      workspaceId,
-      workspaceName,
-      type: row.type,
-      name: row.name,
-      description: row.description,
-      iconUrl: row.iconUrl,
-      enabled: row.enabled,
-      // Field set derived live from the deployed Start; stored placeholders merged
-      // in. Derive even for a disabled block — the source workflow's deployment is
-      // independent of the block's enabled flag, and the edit form needs the real
-      // fields so a save doesn't overwrite the block's stored placeholders.
-      inputFields: applyInputPlaceholders(row.inputs, await deriveInputFields(row.workflowId)),
-      exposedOutputs: row.outputs ?? [],
-    }))
-  )
+  return Promise.all(rows.map(hydrateCustomBlockRow))
+}
+
+/**
+ * The custom block bound to a workflow (with live-derived input fields), or `null`
+ * when the workflow isn't published as a block. One block per workflow is enforced
+ * at publish time. Used by the copilot deploy_custom_block tool.
+ */
+export async function getCustomBlockWithInputsByWorkflowId(
+  workflowId: string
+): Promise<CustomBlockWithInputs | null> {
+  const [row] = await db
+    .select({
+      block: customBlock,
+      workflowName: workflow.name,
+      workspaceId: workflow.workspaceId,
+      workspaceName: workspace.name,
+    })
+    .from(customBlock)
+    .innerJoin(workflow, eq(workflow.id, customBlock.workflowId))
+    .leftJoin(workspace, eq(workspace.id, workflow.workspaceId))
+    .where(eq(customBlock.workflowId, workflowId))
+    .limit(1)
+  return row ? hydrateCustomBlockRow(row) : null
 }
 
 /** Fetch a single custom block row by id. */
diff --git a/apps/sim/package.json b/apps/sim/package.json
index f58c8e61b80..d3c8e6b473b 100644
--- a/apps/sim/package.json
+++ b/apps/sim/package.json
@@ -213,7 +213,7 @@
     "twilio": "5.9.0",
     "undici": "7.28.0",
     "unpdf": "1.4.0",
-    "xlsx": "https://cdn.sheetjs.com/xlsx-0.20.3/xlsx-0.20.3.tgz",
+    "xlsx": "npm:@e965/xlsx@0.20.3",
     "zod": "4.3.6",
     "zustand": "^5.0.13"
   },
diff --git a/bun.lock b/bun.lock
index 0f9ba9efcf1..ebd17dbdbfc 100644
--- a/bun.lock
+++ b/bun.lock
@@ -282,7 +282,7 @@
         "twilio": "5.9.0",
         "undici": "7.28.0",
         "unpdf": "1.4.0",
-        "xlsx": "https://cdn.sheetjs.com/xlsx-0.20.3/xlsx-0.20.3.tgz",
+        "xlsx": "npm:@e965/xlsx@0.20.3",
         "zod": "4.3.6",
         "zustand": "^5.0.13",
       },
@@ -4068,7 +4068,7 @@
 
     "ws": ["ws@8.21.0", "", { "peerDependencies": { "bufferutil": "^4.0.1", "utf-8-validate": ">=5.0.2" }, "optionalPeers": ["bufferutil", "utf-8-validate"] }, "sha512-Vsp28b7DRcimFQvrqu2Wek3z1iYxDCWqHYB8Qsnk/S4RfaCQzPGPyBNuVjJV3cd6UiKtUtp6sNM77gWvzcCH+g=="],
 
-    "xlsx": ["xlsx@https://cdn.sheetjs.com/xlsx-0.20.3/xlsx-0.20.3.tgz", { "bin": { "xlsx": "./bin/xlsx.njs" } }],
+    "xlsx": ["@e965/xlsx@0.20.3", "", { "bin": { "xlsx": "bin/xlsx.njs" } }, "sha512-703RN/3OdsRD5mtse2HBX7Um7xwaP9tlswEG6svOtjqokXoX7rJdQj7DyabD2I+xk22RgaIIU+R6BHgkpZGB/w=="],
 
     "xml": ["xml@1.0.1", "", {}, "sha512-huCv9IH9Tcf95zuYCsQraZtWnJvBtLVE0QHMOs8bWyZAFZNDcYjsPq1nEx8jKA9y+Beo9v+7OBPRisQTjinQMw=="],