From 29c93eeb35655d1b88eb685f57e06c7ac2791bc6 Mon Sep 17 00:00:00 2001
From: Matthias Meister <meister.matthias86@gmail.com>
Date: Thu, 9 Apr 2026 14:28:27 +0200
Subject: [PATCH] feat(agent): implement phase 2 runtime and inline
 clarification

---
 components/canvas/node-types.ts               |   2 +
 components/canvas/nodes/agent-node.tsx        | 314 +++++-
 components/canvas/nodes/agent-output-node.tsx |  72 ++
 convex/_generated/api.d.ts                    |   2 +
 convex/agents.ts                              | 951 ++++++++++++++++++
 convex/canvasGraph.ts                         |  15 +-
 convex/openrouter.ts                          |  61 ++
 lib/agent-models.ts                           |  77 ++
 lib/agent-run-contract.ts                     |  71 ++
 lib/canvas-connection-policy.ts               |   9 +-
 lib/canvas-node-catalog.ts                    |   3 +-
 lib/canvas-utils.ts                           |  21 +-
 tests/agent-node-runtime.test.ts              | 296 ++++++
 tests/agent-output-node.test.ts               | 115 +++
 tests/canvas-connection-policy.test.ts        |  26 +
 .../openrouter-structured-output.test.ts      | 189 ++++
 tests/lib/agent-models.test.ts                |  61 ++
 tests/lib/agent-run-contract.test.ts          |  96 ++
 18 files changed, 2376 insertions(+), 5 deletions(-)
 create mode 100644 components/canvas/nodes/agent-output-node.tsx
 create mode 100644 convex/agents.ts
 create mode 100644 lib/agent-models.ts
 create mode 100644 lib/agent-run-contract.ts
 create mode 100644 tests/agent-node-runtime.test.ts
 create mode 100644 tests/agent-output-node.test.ts
 create mode 100644 tests/convex/openrouter-structured-output.test.ts
 create mode 100644 tests/lib/agent-models.test.ts
 create mode 100644 tests/lib/agent-run-contract.test.ts

diff --git a/components/canvas/node-types.ts b/components/canvas/node-types.ts
index 36e5432..e31d1f1 100644
--- a/components/canvas/node-types.ts
+++ b/components/canvas/node-types.ts
@@ -17,6 +17,7 @@ import DetailAdjustNode from "./nodes/detail-adjust-node";
 import RenderNode from "./nodes/render-node";
 import CropNode from "./nodes/crop-node";
 import AgentNode from "./nodes/agent-node";
+import AgentOutputNode from "./nodes/agent-output-node";
 
 /**
  * Node-Type-Map für React Flow.
@@ -45,4 +46,5 @@ export const nodeTypes = {
   crop: CropNode,
   render: RenderNode,
   agent: AgentNode,
+  "agent-output": AgentOutputNode,
 } as const;
diff --git a/components/canvas/nodes/agent-node.tsx b/components/canvas/nodes/agent-node.tsx
index cda0113..9ddc6ea 100644
--- a/components/canvas/nodes/agent-node.tsx
+++ b/components/canvas/nodes/agent-node.tsx
@@ -1,14 +1,44 @@
 "use client";
 
+import { useCallback, useEffect, useMemo, useState } from "react";
 import { Bot } from "lucide-react";
 import { Handle, Position, type Node, type NodeProps } from "@xyflow/react";
+import { useAction } from "convex/react";
+import type { FunctionReference } from "convex/server";
 
+import { api } from "@/convex/_generated/api";
+import type { Id } from "@/convex/_generated/dataModel";
+import { useCanvasSync } from "@/components/canvas/canvas-sync-context";
+import { useAuthQuery } from "@/hooks/use-auth-query";
+import {
+  DEFAULT_AGENT_MODEL_ID,
+  getAgentModel,
+  getAvailableAgentModels,
+  type AgentModelId,
+} from "@/lib/agent-models";
+import {
+  type AgentClarificationAnswerMap,
+  type AgentClarificationQuestion,
+} from "@/lib/agent-run-contract";
 import { getAgentTemplate } from "@/lib/agent-templates";
+import { normalizePublicTier } from "@/lib/tier-credits";
+import { toast } from "@/lib/toast";
+import { Label } from "@/components/ui/label";
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "@/components/ui/select";
 import BaseNodeWrapper from "./base-node-wrapper";
 
 type AgentNodeData = {
   templateId?: string;
   canvasId?: string;
+  modelId?: string;
+  clarificationQuestions?: AgentClarificationQuestion[];
+  clarificationAnswers?: AgentClarificationAnswerMap | Array<{ id: string; value: string }>;
   _status?: string;
   _statusMessage?: string;
 };
@@ -17,6 +47,68 @@ type AgentNodeType = Node<AgentNodeData, "agent">;
 
 const DEFAULT_AGENT_TEMPLATE_ID = "campaign-distributor";
 
+function useSafeCanvasSync() {
+  try {
+    return useCanvasSync();
+  } catch {
+    return {
+      queueNodeDataUpdate: async () => undefined,
+      status: { isOffline: false, isSyncing: false, pendingCount: 0 },
+    };
+  }
+}
+
+function useSafeSubscription() {
+  try {
+    return useAuthQuery(api.credits.getSubscription);
+  } catch {
+    return undefined;
+  }
+}
+
+function useSafeAction(reference: FunctionReference<"action", "public", any, unknown>) {
+  try {
+    return useAction(reference);
+  } catch {
+    return async (_args: any) => undefined;
+  }
+}
+
+function normalizeClarificationAnswers(raw: AgentNodeData["clarificationAnswers"]): AgentClarificationAnswerMap {
+  if (!raw) {
+    return {};
+  }
+
+  if (Array.isArray(raw)) {
+    const entries = raw
+      .filter((item) => typeof item?.id === "string" && typeof item?.value === "string")
+      .map((item) => [item.id, item.value] as const);
+    return Object.fromEntries(entries);
+  }
+
+  return raw;
+}
+
+function areAnswerMapsEqual(
+  left: AgentClarificationAnswerMap,
+  right: AgentClarificationAnswerMap,
+): boolean {
+  const leftEntries = Object.entries(left);
+  const rightEntries = Object.entries(right);
+
+  if (leftEntries.length !== rightEntries.length) {
+    return false;
+  }
+
+  for (const [key, value] of leftEntries) {
+    if (right[key] !== value) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
 function CompactList({ items }: { items: readonly string[] }) {
   return (
     <ul className="space-y-1">
@@ -29,11 +121,164 @@ function CompactList({ items }: { items: readonly string[] }) {
   );
 }
 
-export default function AgentNode({ data, selected }: NodeProps<AgentNodeType>) {
+export default function AgentNode({ id, data, selected }: NodeProps<AgentNodeType>) {
   const nodeData = data as AgentNodeData;
   const template =
     getAgentTemplate(nodeData.templateId ?? DEFAULT_AGENT_TEMPLATE_ID) ??
     getAgentTemplate(DEFAULT_AGENT_TEMPLATE_ID);
+  const { queueNodeDataUpdate, status } = useSafeCanvasSync();
+  const subscription = useSafeSubscription();
+  const userTier = normalizePublicTier(subscription?.tier ?? "free");
+
+  const availableModels = useMemo(() => getAvailableAgentModels(userTier), [userTier]);
+  const [modelId, setModelId] = useState(nodeData.modelId ?? DEFAULT_AGENT_MODEL_ID);
+  const [clarificationAnswers, setClarificationAnswers] = useState<AgentClarificationAnswerMap>(
+    normalizeClarificationAnswers(nodeData.clarificationAnswers),
+  );
+
+  const agentActionsApi = api as unknown as {
+    agents: {
+      runAgent: FunctionReference<
+        "action",
+        "public",
+        {
+          canvasId: Id<"canvases">;
+          nodeId: Id<"nodes">;
+          modelId: string;
+        },
+        unknown
+      >;
+      resumeAgent: FunctionReference<
+        "action",
+        "public",
+        {
+          canvasId: Id<"canvases">;
+          nodeId: Id<"nodes">;
+          clarificationAnswers: AgentClarificationAnswerMap;
+        },
+        unknown
+      >;
+    };
+  };
+
+  const runAgent = useSafeAction(agentActionsApi.agents.runAgent);
+  const resumeAgent = useSafeAction(agentActionsApi.agents.resumeAgent);
+
+  useEffect(() => {
+    setModelId(nodeData.modelId ?? DEFAULT_AGENT_MODEL_ID);
+  }, [nodeData.modelId]);
+
+  useEffect(() => {
+    const normalized = normalizeClarificationAnswers(nodeData.clarificationAnswers);
+    setClarificationAnswers((current) => {
+      if (areAnswerMapsEqual(current, normalized)) {
+        return current;
+      }
+      return normalized;
+    });
+  }, [nodeData.clarificationAnswers]);
+
+  useEffect(() => {
+    if (availableModels.length === 0) {
+      return;
+    }
+    if (availableModels.some((model) => model.id === modelId)) {
+      return;
+    }
+
+    const nextModelId = availableModels[0]!.id;
+    setModelId(nextModelId);
+  }, [availableModels, modelId]);
+
+  const selectedModel =
+    getAgentModel(modelId) ??
+    availableModels[0] ??
+    getAgentModel(DEFAULT_AGENT_MODEL_ID);
+  const resolvedModelId = selectedModel?.id ?? DEFAULT_AGENT_MODEL_ID;
+  const creditCost = selectedModel?.creditCost ?? 0;
+  const clarificationQuestions = nodeData.clarificationQuestions ?? [];
+
+  const persistNodeData = useCallback(
+    (patch: Partial<AgentNodeData>) => {
+      const raw = data as Record<string, unknown>;
+      const { _status, _statusMessage, ...rest } = raw;
+      void _status;
+      void _statusMessage;
+
+      return queueNodeDataUpdate({
+        nodeId: id as Id<"nodes">,
+        data: {
+          ...rest,
+          ...patch,
+        },
+      });
+    },
+    [data, id, queueNodeDataUpdate],
+  );
+
+  const handleModelChange = useCallback(
+    (value: string) => {
+      setModelId(value);
+      void persistNodeData({ modelId: value });
+    },
+    [persistNodeData],
+  );
+
+  const handleClarificationAnswerChange = useCallback(
+    (questionId: string, value: string) => {
+      setClarificationAnswers((prev) => {
+        const next = {
+          ...prev,
+          [questionId]: value,
+        };
+        void persistNodeData({ clarificationAnswers: next });
+        return next;
+      });
+    },
+    [persistNodeData],
+  );
+
+  const handleRunAgent = useCallback(async () => {
+    if (status.isOffline) {
+      toast.warning(
+        "Offline aktuell nicht unterstuetzt",
+        "Agent-Lauf benoetigt eine aktive Verbindung.",
+      );
+      return;
+    }
+
+    const canvasId = nodeData.canvasId as Id<"canvases"> | undefined;
+    if (!canvasId) {
+      return;
+    }
+
+    await runAgent({
+      canvasId,
+      nodeId: id as Id<"nodes">,
+      modelId: resolvedModelId,
+    });
+  }, [nodeData.canvasId, id, resolvedModelId, runAgent, status.isOffline]);
+
+  const handleSubmitClarification = useCallback(async () => {
+    if (status.isOffline) {
+      toast.warning(
+        "Offline aktuell nicht unterstuetzt",
+        "Agent-Lauf benoetigt eine aktive Verbindung.",
+      );
+      return;
+    }
+
+    const canvasId = nodeData.canvasId as Id<"canvases"> | undefined;
+    if (!canvasId) {
+      return;
+    }
+
+    await resumeAgent({
+      canvasId,
+      nodeId: id as Id<"nodes">,
+      clarificationAnswers,
+    });
+  }, [clarificationAnswers, nodeData.canvasId, id, resumeAgent, status.isOffline]);
 
   if (!template) {
     return null;
@@ -64,6 +309,73 @@ export default function AgentNode({ data, selected }: NodeProps<AgentNodeType>)
           <p className="line-clamp-2 text-xs text-muted-foreground">{template.description}</p>
         </header>
 
+        <section className="space-y-1.5">
+          <Label htmlFor={`agent-model-${id}`} className="text-[10px] font-semibold uppercase tracking-wide text-muted-foreground">
+            Model
+          </Label>
+          <Select value={resolvedModelId} onValueChange={handleModelChange}>
+            <SelectTrigger id={`agent-model-${id}`} className="nodrag nowheel w-full" size="sm">
+              <SelectValue placeholder="Model" />
+            </SelectTrigger>
+            <SelectContent className="nodrag">
+              {(availableModels.length > 0 ? availableModels : [selectedModel]).filter(Boolean).map((model) => (
+                <SelectItem key={model!.id} value={model!.id}>
+                  {model!.label}
+                </SelectItem>
+              ))}
+            </SelectContent>
+          </Select>
+          <p className="text-[11px] text-muted-foreground">
+            {selectedModel?.label ?? resolvedModelId} - {creditCost} Cr
+          </p>
+        </section>
+
+        <section className="space-y-1.5">
+          <button
+            type="button"
+            onClick={() => void handleRunAgent()}
+            className="nodrag w-full rounded-md bg-amber-600 px-3 py-2 text-sm font-medium text-white hover:bg-amber-700"
+          >
+            Run agent
+          </button>
+        </section>
+
+        {clarificationQuestions.length > 0 ? (
+          <section className="space-y-2">
+            <p className="text-[10px] font-semibold uppercase tracking-wide text-muted-foreground">
+              Clarifications
+            </p>
+            {clarificationQuestions.map((question) => (
+              <div key={question.id} className="space-y-1">
+                <label
+                  htmlFor={`agent-${id}-clarification-${question.id}`}
+                  className="text-[11px] text-foreground/90"
+                >
+                  {question.prompt}
+                  {question.required ? " *" : ""}
+                </label>
+                <input
+                  id={`agent-${id}-clarification-${question.id}`}
+                  name={`clarification-${question.id}`}
+                  type="text"
+                  value={clarificationAnswers[question.id] ?? ""}
+                  onChange={(event) =>
+                    handleClarificationAnswerChange(question.id, event.target.value)
+                  }
+                  className="nodrag nowheel w-full rounded-md border border-border bg-background px-2 py-1.5 text-sm"
+                />
+              </div>
+            ))}
+            <button
+              type="button"
+              onClick={() => void handleSubmitClarification()}
+              className="nodrag w-full rounded-md border border-amber-500/50 bg-amber-500/10 px-3 py-2 text-sm font-medium text-amber-800 hover:bg-amber-500/20 dark:text-amber-200"
+            >
+              Submit clarification
+            </button>
+          </section>
+        ) : null}
+
         <section className="space-y-1">
           <p className="text-[10px] font-semibold uppercase tracking-wide text-muted-foreground">
             Channels
diff --git a/components/canvas/nodes/agent-output-node.tsx b/components/canvas/nodes/agent-output-node.tsx
new file mode 100644
index 0000000..6afbf1c
--- /dev/null
+++ b/components/canvas/nodes/agent-output-node.tsx
@@ -0,0 +1,72 @@
+"use client";
+
+import { Handle, Position, type Node, type NodeProps } from "@xyflow/react";
+
+import BaseNodeWrapper from "./base-node-wrapper";
+
+type AgentOutputNodeData = {
+  title?: string;
+  channel?: string;
+  outputType?: string;
+  body?: string;
+  _status?: string;
+  _statusMessage?: string;
+};
+
+type AgentOutputNodeType = Node<AgentOutputNodeData, "agent-output">;
+
+export default function AgentOutputNode({ data, selected }: NodeProps<AgentOutputNodeType>) {
+  const nodeData = data as AgentOutputNodeData;
+
+  return (
+    <BaseNodeWrapper
+      nodeType="agent-output"
+      selected={selected}
+      status={nodeData._status}
+      statusMessage={nodeData._statusMessage}
+      className="min-w-[300px] border-amber-500/30"
+    >
+      <Handle
+        type="target"
+        position={Position.Left}
+        id="agent-output-in"
+        className="!h-3 !w-3 !bg-amber-500 !border-2 !border-background"
+      />
+
+      <div className="flex h-full flex-col gap-3 p-3">
+        <header className="space-y-1">
+          <p className="truncate text-xs font-semibold text-foreground" title={nodeData.title}>
+            {nodeData.title ?? "Agent output"}
+          </p>
+        </header>
+
+        <section className="space-y-1">
+          <p className="text-[10px] font-semibold uppercase tracking-wide text-muted-foreground">
+            Channel
+          </p>
+          <p className="truncate text-xs text-foreground/90" title={nodeData.channel}>
+            {nodeData.channel ?? "-"}
+          </p>
+        </section>
+
+        <section className="space-y-1">
+          <p className="text-[10px] font-semibold uppercase tracking-wide text-muted-foreground">
+            Output Type
+          </p>
+          <p className="truncate text-xs text-foreground/90" title={nodeData.outputType}>
+            {nodeData.outputType ?? "-"}
+          </p>
+        </section>
+
+        <section className="space-y-1">
+          <p className="text-[10px] font-semibold uppercase tracking-wide text-muted-foreground">
+            Body
+          </p>
+          <p className="line-clamp-6 whitespace-pre-wrap text-xs text-foreground/90">
+            {nodeData.body ?? ""}
+          </p>
+        </section>
+      </div>
+    </BaseNodeWrapper>
+  );
+}
diff --git a/convex/_generated/api.d.ts b/convex/_generated/api.d.ts
index 3dec67c..6384311 100644
--- a/convex/_generated/api.d.ts
+++ b/convex/_generated/api.d.ts
@@ -8,6 +8,7 @@
  * @module
  */
 
+import type * as agents from "../agents.js";
 import type * as ai from "../ai.js";
 import type * as ai_errors from "../ai_errors.js";
 import type * as ai_node_data from "../ai_node_data.js";
@@ -41,6 +42,7 @@ import type {
 } from "convex/server";
 
 declare const fullApi: ApiFromModules<{
+  agents: typeof agents;
   ai: typeof ai;
   ai_errors: typeof ai_errors;
   ai_node_data: typeof ai_node_data;
diff --git a/convex/agents.ts b/convex/agents.ts
new file mode 100644
index 0000000..707aa17
--- /dev/null
+++ b/convex/agents.ts
@@ -0,0 +1,951 @@
+import { v } from "convex/values";
+import type { FunctionReference } from "convex/server";
+
+import {
+  action,
+  type ActionCtx,
+  internalAction,
+  internalMutation,
+} from "./_generated/server";
+import { api, internal } from "./_generated/api";
+import type { Doc, Id } from "./_generated/dataModel";
+import { generateStructuredObjectViaOpenRouter } from "./openrouter";
+import { getNodeDataRecord } from "./ai_node_data";
+import { formatTerminalStatusMessage } from "./ai_errors";
+import {
+  areClarificationAnswersComplete,
+  normalizeAgentOutputDraft,
+  type AgentClarificationAnswerMap,
+  type AgentClarificationQuestion,
+  type AgentOutputDraft,
+} from "../lib/agent-run-contract";
+import {
+  DEFAULT_AGENT_MODEL_ID,
+  getAgentModel,
+  isAgentModelAvailableForTier,
+  type AgentModel,
+} from "../lib/agent-models";
+import { getAgentTemplate } from "../lib/agent-templates";
+import { normalizePublicTier } from "../lib/tier-credits";
+
+const ANALYZE_SCHEMA: Record<string, unknown> = {
+  type: "object",
+  additionalProperties: false,
+  required: ["analysisSummary", "clarificationQuestions"],
+  properties: {
+    analysisSummary: { type: "string" },
+    clarificationQuestions: {
+      type: "array",
+      maxItems: 6,
+      items: {
+        type: "object",
+        additionalProperties: false,
+        required: ["id", "prompt", "required"],
+        properties: {
+          id: { type: "string" },
+          prompt: { type: "string" },
+          required: { type: "boolean" },
+        },
+      },
+    },
+  },
+};
+
+const EXECUTE_SCHEMA: Record<string, unknown> = {
+  type: "object",
+  additionalProperties: false,
+  required: ["summary", "outputs"],
+  properties: {
+    summary: { type: "string" },
+    outputs: {
+      type: "array",
+      minItems: 1,
+      maxItems: 6,
+      items: {
+        type: "object",
+        additionalProperties: false,
+        required: ["title", "channel", "outputType", "body"],
+        properties: {
+          title: { type: "string" },
+          channel: { type: "string" },
+          outputType: { type: "string" },
+          body: { type: "string" },
+        },
+      },
+    },
+  },
+};
+
+type InternalApiShape = {
+  canvasGraph: {
+    getInternal: FunctionReference<
+      "query",
+      "internal",
+      { canvasId: Id<"canvases">; userId: string },
+      {
+        canvas: Doc<"canvases">;
+        nodes: Doc<"nodes">[];
+        edges: Doc<"edges">[];
+      }
+    >;
+  };
+  agents: {
+    analyzeAgent: FunctionReference<
+      "action",
+      "internal",
+      {
+        canvasId: Id<"canvases">;
+        nodeId: Id<"nodes">;
+        modelId: string;
+        userId: string;
+        reservationId?: Id<"creditTransactions">;
+        shouldDecrementConcurrency: boolean;
+      },
+      unknown
+    >;
+    executeAgent: FunctionReference<
+      "action",
+      "internal",
+      {
+        canvasId: Id<"canvases">;
+        nodeId: Id<"nodes">;
+        modelId: string;
+        userId: string;
+        analysisSummary: string;
+        reservationId?: Id<"creditTransactions">;
+        shouldDecrementConcurrency: boolean;
+      },
+      unknown
+    >;
+    setAgentAnalyzing: FunctionReference<
+      "mutation",
+      "internal",
+      {
+        nodeId: Id<"nodes">;
+        modelId: string;
+        reservationId?: Id<"creditTransactions">;
+        shouldDecrementConcurrency: boolean;
+      },
+      unknown
+    >;
+    upsertClarificationAnswers: FunctionReference<
+      "mutation",
+      "internal",
+      {
+        nodeId: Id<"nodes">;
+        clarificationAnswers: AgentClarificationAnswerMap;
+      },
+      { answers: AgentClarificationAnswerMap; questions: AgentClarificationQuestion[] }
+    >;
+    setAgentError: FunctionReference<
+      "mutation",
+      "internal",
+      {
+        nodeId: Id<"nodes">;
+        statusMessage: string;
+      },
+      unknown
+    >;
+    setAgentClarifying: FunctionReference<
+      "mutation",
+      "internal",
+      {
+        nodeId: Id<"nodes">;
+        clarificationQuestions: AgentClarificationQuestion[];
+      },
+      unknown
+    >;
+    setAgentExecuting: FunctionReference<
+      "mutation",
+      "internal",
+      { nodeId: Id<"nodes">; statusMessage?: string },
+      unknown
+    >;
+    finalizeAgentSuccessWithOutputs: FunctionReference<
+      "mutation",
+      "internal",
+      {
+        canvasId: Id<"canvases">;
+        nodeId: Id<"nodes">;
+        outputs: AgentOutputDraft[];
+        summary: string;
+      },
+      { outputNodeIds: Id<"nodes">[] }
+    >;
+  };
+  credits: {
+    commitInternal: FunctionReference<
+      "mutation",
+      "internal",
+      { transactionId: Id<"creditTransactions">; actualCost: number; openRouterCost?: number },
+      unknown
+    >;
+    releaseInternal: FunctionReference<
+      "mutation",
+      "internal",
+      { transactionId: Id<"creditTransactions"> },
+      unknown
+    >;
+    checkAbuseLimits: FunctionReference<"mutation", "internal", {}, unknown>;
+    incrementUsage: FunctionReference<"mutation", "internal", {}, unknown>;
+    decrementConcurrency: FunctionReference<
+      "mutation",
+      "internal",
+      { userId?: string },
+      unknown
+    >;
+  };
+};
+
+const internalApi = internal as unknown as InternalApiShape;
+
+function trimText(value: unknown): string {
+  return typeof value === "string" ? value.trim() : "";
+}
+
+function normalizeAnswerMap(raw: unknown): AgentClarificationAnswerMap {
+  if (!raw || typeof raw !== "object" || Array.isArray(raw)) {
+    return {};
+  }
+
+  const normalized: AgentClarificationAnswerMap = {};
+  for (const [key, value] of Object.entries(raw)) {
+    const id = trimText(key);
+    if (!id) {
+      continue;
+    }
+    normalized[id] = trimText(value);
+  }
+  return normalized;
+}
+
+function normalizeClarificationQuestions(raw: unknown): AgentClarificationQuestion[] {
+  if (!Array.isArray(raw)) {
+    return [];
+  }
+
+  const seenIds = new Set<string>();
+  const questions: AgentClarificationQuestion[] = [];
+
+  for (let index = 0; index < raw.length; index += 1) {
+    const item = raw[index];
+    if (!item || typeof item !== "object") {
+      continue;
+    }
+
+    const itemRecord = item as Record<string, unknown>;
+    const prompt = trimText(itemRecord.prompt);
+    if (!prompt) {
+      continue;
+    }
+
+    const rawId = trimText(itemRecord.id).replace(/\s+/g, "-").toLowerCase();
+    const fallbackId = `q-${index + 1}`;
+    const id = rawId || fallbackId;
+
+    if (seenIds.has(id)) {
+      continue;
+    }
+
+    seenIds.add(id);
+    questions.push({
+      id,
+      prompt,
+      required: itemRecord.required !== false,
+    });
+  }
+
+  return questions;
+}
+
+function serializeNodeDataForPrompt(data: unknown): string {
+  if (data === undefined) {
+    return "{}";
+  }
+  try {
+    return JSON.stringify(data).slice(0, 1200);
+  } catch {
+    return "{}";
+  }
+}
+
+function collectIncomingContext(
+  graph: { nodes: Doc<"nodes">[]; edges: Doc<"edges">[] },
+  agentNodeId: Id<"nodes">,
+): string {
+  const nodeById = new Map(graph.nodes.map((node) => [node._id, node] as const));
+  const incomingEdges = graph.edges.filter((edge) => edge.targetNodeId === agentNodeId);
+
+  if (incomingEdges.length === 0) {
+    return "No incoming nodes connected to this agent.";
+  }
+
+  const lines: string[] = [];
+  for (const edge of incomingEdges) {
+    const source = nodeById.get(edge.sourceNodeId);
+    if (!source) {
+      continue;
+    }
+    lines.push(
+      `- nodeId=${source._id}, type=${source.type}, status=${source.status}, data=${serializeNodeDataForPrompt(source.data)}`,
+    );
+  }
+
+  return lines.length > 0 ? lines.join("\n") : "No incoming nodes connected to this agent.";
+}
+
+function getAgentNodeFromGraph(
+  graph: { nodes: Doc<"nodes">[] },
+  nodeId: Id<"nodes">,
+): Doc<"nodes"> {
+  const agentNode = graph.nodes.find((node) => node._id === nodeId);
+  if (!agentNode) {
+    throw new Error("Agent node not found");
+  }
+  if (agentNode.type !== "agent") {
+    throw new Error("Node must be an agent node");
+  }
+  return agentNode;
+}
+
+async function releaseInternalReservationBestEffort(
+  ctx: ActionCtx,
+  reservationId: Id<"creditTransactions"> | undefined,
+) {
+  if (!reservationId) {
+    return;
+  }
+  try {
+    await ctx.runMutation(internalApi.credits.releaseInternal, {
+      transactionId: reservationId,
+    });
+  } catch {
+    // Keep terminal node updates resilient even when cleanup fails.
+  }
+}
+
+async function releasePublicReservationBestEffort(
+  ctx: ActionCtx,
+  reservationId: Id<"creditTransactions"> | null,
+) {
+  if (!reservationId) {
+    return;
+  }
+  try {
+    await ctx.runMutation(api.credits.release, {
+      transactionId: reservationId,
+    });
+  } catch {
+    // Prefer surfacing orchestration errors over cleanup issues.
+  }
+}
+
+async function decrementConcurrencyIfNeeded(
+  ctx: ActionCtx,
+  shouldDecrementConcurrency: boolean,
+  userId: string,
+) {
+  if (!shouldDecrementConcurrency) {
+    return;
+  }
+  await ctx.runMutation(internalApi.credits.decrementConcurrency, {
+    userId,
+  });
+}
+
+function getSelectedModelOrThrow(modelId: string): AgentModel {
+  const selectedModel = getAgentModel(modelId);
+  if (!selectedModel) {
+    throw new Error(`Unknown agent model: ${modelId}`);
+  }
+  return selectedModel;
+}
+
+function assertAgentModelTier(model: AgentModel, tier: string | undefined): void {
+  const normalizedTier = normalizePublicTier(tier);
+  if (!isAgentModelAvailableForTier(normalizedTier, model.id)) {
+    throw new Error(`Model ${model.id} requires ${model.minTier} tier`);
+  }
+}
+
+export const setAgentAnalyzing = internalMutation({
+  args: {
+    nodeId: v.id("nodes"),
+    modelId: v.string(),
+    reservationId: v.optional(v.id("creditTransactions")),
+    shouldDecrementConcurrency: v.boolean(),
+  },
+  handler: async (ctx, args) => {
+    const node = await ctx.db.get(args.nodeId);
+    if (!node) {
+      throw new Error("Node not found");
+    }
+    if (node.type !== "agent") {
+      throw new Error("Node must be an agent node");
+    }
+
+    const prev = getNodeDataRecord(node.data);
+
+    await ctx.db.patch(args.nodeId, {
+      status: "analyzing",
+      statusMessage: "Step 1/2 - analyzing inputs",
+      retryCount: 0,
+      data: {
+        ...prev,
+        modelId: args.modelId,
+        reservationId: args.reservationId,
+        shouldDecrementConcurrency: args.shouldDecrementConcurrency,
+      },
+    });
+  },
+});
+
+export const setAgentClarifying = internalMutation({
+  args: {
+    nodeId: v.id("nodes"),
+    clarificationQuestions: v.array(
+      v.object({
+        id: v.string(),
+        prompt: v.string(),
+        required: v.boolean(),
+      }),
+    ),
+  },
+  handler: async (ctx, args) => {
+    const node = await ctx.db.get(args.nodeId);
+    if (!node) {
+      throw new Error("Node not found");
+    }
+
+    const prev = getNodeDataRecord(node.data);
+    const answers = normalizeAnswerMap(prev.clarificationAnswers);
+
+    await ctx.db.patch(args.nodeId, {
+      status: "clarifying",
+      statusMessage: "Clarification required before execution",
+      data: {
+        ...prev,
+        clarificationQuestions: args.clarificationQuestions,
+        clarificationAnswers: answers,
+      },
+    });
+  },
+});
+
+export const setAgentExecuting = internalMutation({
+  args: {
+    nodeId: v.id("nodes"),
+    statusMessage: v.optional(v.string()),
+  },
+  handler: async (ctx, args) => {
+    const node = await ctx.db.get(args.nodeId);
+    if (!node) {
+      throw new Error("Node not found");
+    }
+    const prev = getNodeDataRecord(node.data);
+
+    await ctx.db.patch(args.nodeId, {
+      status: "executing",
+      statusMessage: args.statusMessage ?? "Step 2/2 - generating outputs",
+      data: {
+        ...prev,
+        clarificationQuestions: [],
+      },
+    });
+  },
+});
+
+export const setAgentError = internalMutation({
+  args: {
+    nodeId: v.id("nodes"),
+    statusMessage: v.string(),
+  },
+  handler: async (ctx, args) => {
+    const node = await ctx.db.get(args.nodeId);
+    if (!node) {
+      throw new Error("Node not found");
+    }
+    const prev = getNodeDataRecord(node.data);
+
+    await ctx.db.patch(args.nodeId, {
+      status: "error",
+      statusMessage: args.statusMessage,
+      data: {
+        ...prev,
+        reservationId: undefined,
+        shouldDecrementConcurrency: undefined,
+      },
+    });
+  },
+});
+
+export const upsertClarificationAnswers = internalMutation({
+  args: {
+    nodeId: v.id("nodes"),
+    clarificationAnswers: v.record(v.string(), v.string()),
+  },
+  handler: async (ctx, args) => {
+    const node = await ctx.db.get(args.nodeId);
+    if (!node) {
+      throw new Error("Node not found");
+    }
+    if (node.type !== "agent") {
+      throw new Error("Node must be an agent node");
+    }
+
+    const prev = getNodeDataRecord(node.data);
+    const currentAnswers = normalizeAnswerMap(prev.clarificationAnswers);
+    const nextAnswers: AgentClarificationAnswerMap = {
+      ...currentAnswers,
+      ...normalizeAnswerMap(args.clarificationAnswers),
+    };
+    const questions = normalizeClarificationQuestions(prev.clarificationQuestions);
+
+    await ctx.db.patch(args.nodeId, {
+      data: {
+        ...prev,
+        clarificationAnswers: nextAnswers,
+      },
+    });
+
+    return {
+      answers: nextAnswers,
+      questions,
+    };
+  },
+});
+
+export const finalizeAgentSuccessWithOutputs = internalMutation({
+  args: {
+    canvasId: v.id("canvases"),
+    nodeId: v.id("nodes"),
+    outputs: v.array(
+      v.object({
+        title: v.optional(v.string()),
+        channel: v.optional(v.string()),
+        outputType: v.optional(v.string()),
+        body: v.optional(v.string()),
+      }),
+    ),
+    summary: v.string(),
+  },
+  handler: async (ctx, args) => {
+    const node = await ctx.db.get(args.nodeId);
+    if (!node) {
+      throw new Error("Node not found");
+    }
+    if (node.type !== "agent") {
+      throw new Error("Node must be an agent node");
+    }
+    if (node.canvasId !== args.canvasId) {
+      throw new Error("Agent node does not belong to canvas");
+    }
+
+    const prev = getNodeDataRecord(node.data);
+    const existingOutputNodeIds = Array.isArray(prev.outputNodeIds)
+      ? prev.outputNodeIds.filter((value): value is Id<"nodes"> => typeof value === "string")
+      : [];
+
+    const baseX = node.positionX + node.width + 120;
+    const baseY = node.positionY;
+    const outputNodeIds: Id<"nodes">[] = [];
+
+    for (let index = 0; index < args.outputs.length; index += 1) {
+      const normalized = normalizeAgentOutputDraft(args.outputs[index] ?? {});
+      const outputNodeId = await ctx.db.insert("nodes", {
+        canvasId: args.canvasId,
+        type: "agent-output",
+        positionX: baseX,
+        positionY: baseY + index * 220,
+        width: 360,
+        height: 260,
+        status: "done",
+        retryCount: 0,
+        data: {
+          title: normalized.title,
+          channel: normalized.channel,
+          outputType: normalized.outputType,
+          body: normalized.body,
+        },
+      });
+      outputNodeIds.push(outputNodeId);
+
+      await ctx.db.insert("edges", {
+        canvasId: args.canvasId,
+        sourceNodeId: args.nodeId,
+        targetNodeId: outputNodeId,
+        sourceHandle: undefined,
+        targetHandle: "agent-output-in",
+      });
+    }
+
+    await ctx.db.patch(args.nodeId, {
+      status: "done",
+      statusMessage: undefined,
+      retryCount: 0,
+      data: {
+        ...prev,
+        clarificationQuestions: [],
+        outputNodeIds: [...existingOutputNodeIds, ...outputNodeIds],
+        lastRunSummary: trimText(args.summary),
+        reservationId: undefined,
+        shouldDecrementConcurrency: undefined,
+      },
+    });
+
+    await ctx.db.patch(args.canvasId, {
+      updatedAt: Date.now(),
+    });
+
+    return {
+      outputNodeIds,
+    };
+  },
+});
+
+export const analyzeAgent = internalAction({
+  args: {
+    canvasId: v.id("canvases"),
+    nodeId: v.id("nodes"),
+    modelId: v.string(),
+    userId: v.string(),
+    reservationId: v.optional(v.id("creditTransactions")),
+    shouldDecrementConcurrency: v.boolean(),
+  },
+  handler: async (ctx, args) => {
+    try {
+      const apiKey = process.env.OPENROUTER_API_KEY;
+      if (!apiKey) {
+        throw new Error("OPENROUTER_API_KEY is not set");
+      }
+
+      const graph = await ctx.runQuery(internalApi.canvasGraph.getInternal, {
+        canvasId: args.canvasId,
+        userId: args.userId,
+      });
+      const agentNode = getAgentNodeFromGraph(graph, args.nodeId);
+      const agentData = getNodeDataRecord(agentNode.data);
+      const template = getAgentTemplate(trimText(agentData.templateId) || "campaign-distributor");
+      const existingAnswers = normalizeAnswerMap(agentData.clarificationAnswers);
+      const incomingContext = collectIncomingContext(graph, args.nodeId);
+
+      const analysis = await generateStructuredObjectViaOpenRouter<{
+        analysisSummary: string;
+        clarificationQuestions: AgentClarificationQuestion[];
+      }>(apiKey, {
+        model: args.modelId,
+        schemaName: "agent_analyze_result",
+        schema: ANALYZE_SCHEMA,
+        messages: [
+          {
+            role: "system",
+            content:
+              "You are the LemonSpace Agent Analyzer. Inspect incoming canvas context and decide if clarification is required before execution. Ask only necessary short questions.",
+          },
+          {
+            role: "user",
+            content: [
+              `Template: ${template?.name ?? "Unknown template"}`,
+              `Template description: ${template?.description ?? ""}`,
+              "Incoming node context:",
+              incomingContext,
+              `Current clarification answers: ${JSON.stringify(existingAnswers)}`,
+              "Return structured JSON matching the schema.",
+            ].join("\n\n"),
+          },
+        ],
+      });
+
+      const clarificationQuestions = normalizeClarificationQuestions(
+        analysis.clarificationQuestions,
+      );
+      const hasRequiredGaps = !areClarificationAnswersComplete(
+        clarificationQuestions,
+        existingAnswers,
+      );
+
+      if (clarificationQuestions.length > 0 && hasRequiredGaps) {
+        await ctx.runMutation(internalApi.agents.setAgentClarifying, {
+          nodeId: args.nodeId,
+          clarificationQuestions,
+        });
+        return;
+      }
+
+      await ctx.runMutation(internalApi.agents.setAgentExecuting, {
+        nodeId: args.nodeId,
+      });
+
+      await ctx.scheduler.runAfter(0, internalApi.agents.executeAgent, {
+        canvasId: args.canvasId,
+        nodeId: args.nodeId,
+        modelId: args.modelId,
+        userId: args.userId,
+        analysisSummary: trimText(analysis.analysisSummary),
+        reservationId: args.reservationId,
+        shouldDecrementConcurrency: args.shouldDecrementConcurrency,
+      });
+    } catch (error) {
+      await releaseInternalReservationBestEffort(ctx, args.reservationId);
+      await ctx.runMutation(internalApi.agents.setAgentError, {
+        nodeId: args.nodeId,
+        statusMessage: formatTerminalStatusMessage(error),
+      });
+      await decrementConcurrencyIfNeeded(ctx, args.shouldDecrementConcurrency, args.userId);
+    }
+  },
+});
+
+export const executeAgent = internalAction({
+  args: {
+    canvasId: v.id("canvases"),
+    nodeId: v.id("nodes"),
+    modelId: v.string(),
+    userId: v.string(),
+    analysisSummary: v.string(),
+    reservationId: v.optional(v.id("creditTransactions")),
+    shouldDecrementConcurrency: v.boolean(),
+  },
+  handler: async (ctx, args) => {
+    try {
+      const apiKey = process.env.OPENROUTER_API_KEY;
+      if (!apiKey) {
+        throw new Error("OPENROUTER_API_KEY is not set");
+      }
+
+      const selectedModel = getSelectedModelOrThrow(args.modelId);
+      const graph = await ctx.runQuery(internalApi.canvasGraph.getInternal, {
+        canvasId: args.canvasId,
+        userId: args.userId,
+      });
+      const agentNode = getAgentNodeFromGraph(graph, args.nodeId);
+      const agentData = getNodeDataRecord(agentNode.data);
+      const template = getAgentTemplate(trimText(agentData.templateId) || "campaign-distributor");
+      const clarificationAnswers = normalizeAnswerMap(agentData.clarificationAnswers);
+      const incomingContext = collectIncomingContext(graph, args.nodeId);
+
+      const execution = await generateStructuredObjectViaOpenRouter<{
+        summary: string;
+        outputs: AgentOutputDraft[];
+      }>(apiKey, {
+        model: args.modelId,
+        schemaName: "agent_execute_result",
+        schema: EXECUTE_SCHEMA,
+        messages: [
+          {
+            role: "system",
+            content:
+              "You are the LemonSpace Agent Executor. Produce concrete channel outputs from context and clarification answers. Output concise, actionable drafts.",
+          },
+          {
+            role: "user",
+            content: [
+              `Template: ${template?.name ?? "Unknown template"}`,
+              `Template description: ${template?.description ?? ""}`,
+              `Analyze summary: ${trimText(args.analysisSummary)}`,
+              `Clarification answers: ${JSON.stringify(clarificationAnswers)}`,
+              "Incoming node context:",
+              incomingContext,
+              "Return structured JSON matching the schema.",
+            ].join("\n\n"),
+          },
+        ],
+      });
+
+      const outputs = Array.isArray(execution.outputs) ? execution.outputs : [];
+      if (outputs.length === 0) {
+        throw new Error("Agent execution returned no outputs");
+      }
+
+      await ctx.runMutation(internalApi.agents.finalizeAgentSuccessWithOutputs, {
+        canvasId: args.canvasId,
+        nodeId: args.nodeId,
+        outputs,
+        summary: execution.summary,
+      });
+
+      if (args.reservationId) {
+        await ctx.runMutation(internalApi.credits.commitInternal, {
+          transactionId: args.reservationId,
+          actualCost: selectedModel.creditCost,
+        });
+      }
+
+      await decrementConcurrencyIfNeeded(ctx, args.shouldDecrementConcurrency, args.userId);
+    } catch (error) {
+      await releaseInternalReservationBestEffort(ctx, args.reservationId);
+      await ctx.runMutation(internalApi.agents.setAgentError, {
+        nodeId: args.nodeId,
+        statusMessage: formatTerminalStatusMessage(error),
+      });
+      await decrementConcurrencyIfNeeded(ctx, args.shouldDecrementConcurrency, args.userId);
+    }
+  },
+});
+
+export const runAgent = action({
+  args: {
+    canvasId: v.id("canvases"),
+    nodeId: v.id("nodes"),
+    modelId: v.string(),
+  },
+  handler: async (ctx, args): Promise<{ queued: true; nodeId: Id<"nodes"> }> => {
+    const canvas = await ctx.runQuery(api.canvases.get, {
+      canvasId: args.canvasId,
+    });
+    if (!canvas) {
+      throw new Error("Canvas not found");
+    }
+
+    const node = await ctx.runQuery(api.nodes.get, {
+      nodeId: args.nodeId,
+      includeStorageUrl: false,
+    });
+    if (!node) {
+      throw new Error("Node not found");
+    }
+    if (node.canvasId !== args.canvasId) {
+      throw new Error("Node does not belong to canvas");
+    }
+    if (node.type !== "agent") {
+      throw new Error("Node must be an agent node");
+    }
+
+    const selectedModel = getSelectedModelOrThrow(args.modelId);
+    const subscription = await ctx.runQuery(api.credits.getSubscription, {});
+    assertAgentModelTier(selectedModel, subscription?.tier);
+
+    await ctx.runMutation(internalApi.credits.checkAbuseLimits, {});
+
+    const internalCreditsEnabled = process.env.INTERNAL_CREDITS_ENABLED === "true";
+    let usageIncremented = false;
+    const reservationId: Id<"creditTransactions"> | null = internalCreditsEnabled
+      ? await ctx.runMutation(api.credits.reserve, {
+          estimatedCost: selectedModel.creditCost,
+          description: `Agent-Lauf - ${selectedModel.label}`,
+          nodeId: args.nodeId,
+          canvasId: args.canvasId,
+          model: selectedModel.id,
+          provider: "openrouter",
+        })
+      : null;
+
+    if (!internalCreditsEnabled) {
+      await ctx.runMutation(internalApi.credits.incrementUsage, {});
+      usageIncremented = true;
+    }
+
+    let scheduled = false;
+    try {
+      await ctx.runMutation(internalApi.agents.setAgentAnalyzing, {
+        nodeId: args.nodeId,
+        modelId: selectedModel.id,
+        reservationId: reservationId ?? undefined,
+        shouldDecrementConcurrency: usageIncremented,
+      });
+
+      await ctx.scheduler.runAfter(0, internalApi.agents.analyzeAgent, {
+        canvasId: args.canvasId,
+        nodeId: args.nodeId,
+        modelId: selectedModel.id,
+        userId: canvas.ownerId,
+        reservationId: reservationId ?? undefined,
+        shouldDecrementConcurrency: usageIncremented,
+      });
+      scheduled = true;
+      return { queued: true, nodeId: args.nodeId };
+    } catch (error) {
+      await releasePublicReservationBestEffort(ctx, reservationId);
+      await ctx.runMutation(internalApi.agents.setAgentError, {
+        nodeId: args.nodeId,
+        statusMessage: formatTerminalStatusMessage(error),
+      });
+
+      throw error;
+    } finally {
+      if (usageIncremented && !scheduled) {
+        await ctx.runMutation(internalApi.credits.decrementConcurrency, {
+          userId: canvas.ownerId,
+        });
+      }
+    }
+  },
+});
+
+export const resumeAgent = action({
+  args: {
+    canvasId: v.id("canvases"),
+    nodeId: v.id("nodes"),
+    clarificationAnswers: v.record(v.string(), v.string()),
+  },
+  handler: async (ctx, args): Promise<{ queued: true; nodeId: Id<"nodes"> }> => {
+    const canvas = await ctx.runQuery(api.canvases.get, {
+      canvasId: args.canvasId,
+    });
+    if (!canvas) {
+      throw new Error("Canvas not found");
+    }
+
+    const node = await ctx.runQuery(api.nodes.get, {
+      nodeId: args.nodeId,
+      includeStorageUrl: false,
+    });
+    if (!node) {
+      throw new Error("Node not found");
+    }
+    if (node.canvasId !== args.canvasId) {
+      throw new Error("Node does not belong to canvas");
+    }
+    if (node.type !== "agent") {
+      throw new Error("Node must be an agent node");
+    }
+
+    const upserted = await ctx.runMutation(internalApi.agents.upsertClarificationAnswers, {
+      nodeId: args.nodeId,
+      clarificationAnswers: args.clarificationAnswers,
+    });
+
+    if (!areClarificationAnswersComplete(upserted.questions, upserted.answers)) {
+      throw new Error("Please answer all required clarification questions before resuming");
+    }
+
+    const nodeData = getNodeDataRecord(node.data);
+    const modelId = trimText(nodeData.modelId) || DEFAULT_AGENT_MODEL_ID;
+    const selectedModel = getSelectedModelOrThrow(modelId);
+    const reservationId =
+      typeof nodeData.reservationId === "string"
+        ? (nodeData.reservationId as Id<"creditTransactions">)
+        : undefined;
+    const shouldDecrementConcurrency = nodeData.shouldDecrementConcurrency === true;
+
+    const subscription = await ctx.runQuery(api.credits.getSubscription, {});
+    assertAgentModelTier(selectedModel, subscription?.tier);
+
+    try {
+      await ctx.runMutation(internalApi.agents.setAgentAnalyzing, {
+        nodeId: args.nodeId,
+        modelId,
+        reservationId,
+        shouldDecrementConcurrency,
+      });
+
+      await ctx.scheduler.runAfter(0, internalApi.agents.analyzeAgent, {
+        canvasId: args.canvasId,
+        nodeId: args.nodeId,
+        modelId,
+        userId: canvas.ownerId,
+        reservationId,
+        shouldDecrementConcurrency,
+      });
+
+      return { queued: true, nodeId: args.nodeId };
+    } catch (error) {
+      await releasePublicReservationBestEffort(ctx, reservationId ?? null);
+      await ctx.runMutation(internalApi.agents.setAgentError, {
+        nodeId: args.nodeId,
+        statusMessage: formatTerminalStatusMessage(error),
+      });
+      throw error;
+    }
+  },
+});
diff --git a/convex/canvasGraph.ts b/convex/canvasGraph.ts
index 8a603d6..78f15b4 100644
--- a/convex/canvasGraph.ts
+++ b/convex/canvasGraph.ts
@@ -1,7 +1,7 @@
 import { v } from "convex/values";
 
 import type { Id } from "./_generated/dataModel";
-import { query, type QueryCtx } from "./_generated/server";
+import { internalQuery, query, type QueryCtx } from "./_generated/server";
 import { requireAuth } from "./helpers";
 
 const PERFORMANCE_LOG_THRESHOLD_MS = 250;
@@ -64,3 +64,16 @@ export const get = query({
     return { nodes, edges };
   },
 });
+
+export const getInternal = internalQuery({
+  args: {
+    canvasId: v.id("canvases"),
+    userId: v.string(),
+  },
+  handler: async (ctx, { canvasId, userId }) => {
+    return loadCanvasGraph(ctx, {
+      canvasId,
+      userId,
+    });
+  },
+});
diff --git a/convex/openrouter.ts b/convex/openrouter.ts
index 7dfa320..2e0e245 100644
--- a/convex/openrouter.ts
+++ b/convex/openrouter.ts
@@ -2,6 +2,67 @@ import { ConvexError } from "convex/values";
 
 export const OPENROUTER_BASE_URL = "https://openrouter.ai/api/v1";
 
+export async function generateStructuredObjectViaOpenRouter<T>(
+  apiKey: string,
+  args: {
+    model: string;
+    messages: Array<{
+      role: "system" | "user" | "assistant";
+      content: string;
+    }>;
+    schemaName: string;
+    schema: Record<string, unknown>;
+  },
+): Promise<T> {
+  const response = await fetch(`${OPENROUTER_BASE_URL}/chat/completions`, {
+    method: "POST",
+    headers: {
+      Authorization: `Bearer ${apiKey}`,
+      "Content-Type": "application/json",
+      "HTTP-Referer": "https://app.lemonspace.io",
+      "X-Title": "LemonSpace",
+    },
+    body: JSON.stringify({
+      model: args.model,
+      messages: args.messages,
+      response_format: {
+        type: "json_schema",
+        json_schema: {
+          name: args.schemaName,
+          strict: true,
+          schema: args.schema,
+        },
+      },
+    }),
+  });
+
+  if (!response.ok) {
+    const errorText = await response.text();
+    throw new ConvexError({
+      code: "OPENROUTER_STRUCTURED_OUTPUT_HTTP_ERROR",
+      status: response.status,
+      message: errorText,
+    });
+  }
+
+  const data = await response.json();
+  const content = data?.choices?.[0]?.message?.content;
+
+  if (typeof content !== "string" || content.trim() === "") {
+    throw new ConvexError({
+      code: "OPENROUTER_STRUCTURED_OUTPUT_MISSING_CONTENT",
+    });
+  }
+
+  try {
+    return JSON.parse(content) as T;
+  } catch {
+    throw new ConvexError({
+      code: "OPENROUTER_STRUCTURED_OUTPUT_INVALID_JSON",
+    });
+  }
+}
+
 export interface OpenRouterModel {
   id: string;
   name: string;
diff --git a/lib/agent-models.ts b/lib/agent-models.ts
new file mode 100644
index 0000000..158bae2
--- /dev/null
+++ b/lib/agent-models.ts
@@ -0,0 +1,77 @@
+export type AgentModelId =
+  | "openai/gpt-5.4-nano"
+  | "openai/gpt-5.4-mini"
+  | "openai/gpt-5.4"
+  | "openai/gpt-5.4-pro";
+
+export type AgentModelMinTier = "starter" | "max";
+export type AgentModelAccessTier = "free" | "starter" | "pro" | "max" | "business";
+
+export interface AgentModel {
+  id: AgentModelId;
+  label: string;
+  minTier: AgentModelMinTier;
+  creditCost: number;
+  description: string;
+}
+
+export const AGENT_MODELS = {
+  "openai/gpt-5.4-nano": {
+    id: "openai/gpt-5.4-nano",
+    label: "GPT-5.4 Nano",
+    minTier: "starter",
+    creditCost: 6,
+    description: "Fastest option for lightweight agent runs",
+  },
+  "openai/gpt-5.4-mini": {
+    id: "openai/gpt-5.4-mini",
+    label: "GPT-5.4 Mini",
+    minTier: "starter",
+    creditCost: 15,
+    description: "Balanced quality and latency for default use",
+  },
+  "openai/gpt-5.4": {
+    id: "openai/gpt-5.4",
+    label: "GPT-5.4",
+    minTier: "starter",
+    creditCost: 38,
+    description: "Higher reasoning quality for complex tasks",
+  },
+  "openai/gpt-5.4-pro": {
+    id: "openai/gpt-5.4-pro",
+    label: "GPT-5.4 Pro",
+    minTier: "max",
+    creditCost: 180,
+    description: "Top-tier capability for hardest workflows",
+  },
+} as const satisfies Record<AgentModelId, AgentModel>;
+
+export const DEFAULT_AGENT_MODEL_ID: AgentModelId = "openai/gpt-5.4-mini";
+
+const AGENT_MODEL_IDS = Object.keys(AGENT_MODELS) as AgentModelId[];
+
+const AGENT_MODEL_TIER_ORDER: Record<AgentModelAccessTier, number> = {
+  free: 0,
+  starter: 1,
+  pro: 2,
+  max: 3,
+  business: 4,
+};
+
+export function getAgentModel(id: string): AgentModel | undefined {
+  return AGENT_MODELS[id as AgentModelId];
+}
+
+export function isAgentModelAvailableForTier(
+  tier: AgentModelAccessTier,
+  modelId: AgentModelId,
+): boolean {
+  const model = AGENT_MODELS[modelId];
+  return AGENT_MODEL_TIER_ORDER[model.minTier] <= AGENT_MODEL_TIER_ORDER[tier];
+}
+
+export function getAvailableAgentModels(tier: AgentModelAccessTier): AgentModel[] {
+  return AGENT_MODEL_IDS.map((id) => AGENT_MODELS[id]).filter((model) =>
+    isAgentModelAvailableForTier(tier, model.id),
+  );
+}
diff --git a/lib/agent-run-contract.ts b/lib/agent-run-contract.ts
new file mode 100644
index 0000000..c2a3f0a
--- /dev/null
+++ b/lib/agent-run-contract.ts
@@ -0,0 +1,71 @@
+export type AgentClarificationQuestion = {
+  id: string;
+  prompt: string;
+  required: boolean;
+};
+
+export type AgentClarificationAnswerMap = Partial<Record<string, string>>;
+
+export type AgentOutputDraft = {
+  title?: string;
+  channel?: string;
+  outputType?: string;
+  body?: string;
+};
+
+export type AgentExecutionPlan = {
+  steps: string[];
+  outputs: AgentOutputDraft[];
+};
+
+export type AgentAnalyzeResult = {
+  clarificationQuestions: AgentClarificationQuestion[];
+  executionPlan: AgentExecutionPlan | null;
+  outputDrafts: AgentOutputDraft[];
+};
+
+const SAFE_FALLBACK_TITLE = "Untitled";
+const SAFE_FALLBACK_CHANNEL = "general";
+const SAFE_FALLBACK_OUTPUT_TYPE = "text";
+
+function trimString(value: unknown): string {
+  return typeof value === "string" ? value.trim() : "";
+}
+
+export function areClarificationAnswersComplete(
+  questions: AgentClarificationQuestion[],
+  answers: AgentClarificationAnswerMap,
+): boolean {
+  for (const question of questions) {
+    if (!question.required) {
+      continue;
+    }
+
+    if (trimString(answers[question.id]) === "") {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+export function normalizeAgentOutputDraft(
+  draft: AgentOutputDraft,
+): AgentOutputDraft & {
+  title: string;
+  channel: string;
+  outputType: string;
+  body: string;
+} {
+  const title = trimString(draft.title) || SAFE_FALLBACK_TITLE;
+  const channel = trimString(draft.channel) || SAFE_FALLBACK_CHANNEL;
+  const outputType = trimString(draft.outputType) || SAFE_FALLBACK_OUTPUT_TYPE;
+
+  return {
+    ...draft,
+    title,
+    channel,
+    outputType,
+    body: trimString(draft.body),
+  };
+}
diff --git a/lib/canvas-connection-policy.ts b/lib/canvas-connection-policy.ts
index 4cb51bb..54cb629 100644
--- a/lib/canvas-connection-policy.ts
+++ b/lib/canvas-connection-policy.ts
@@ -65,7 +65,8 @@ export type CanvasConnectionValidationReason =
   | "compare-incoming-limit"
   | "adjustment-target-forbidden"
   | "render-source-invalid"
-  | "agent-source-invalid";
+  | "agent-source-invalid"
+  | "agent-output-source-invalid";
 
 export function validateCanvasConnectionPolicy(args: {
   sourceType: string;
@@ -74,6 +75,10 @@ export function validateCanvasConnectionPolicy(args: {
 }): CanvasConnectionValidationReason | null {
   const { sourceType, targetType, targetIncomingCount } = args;
 
+  if (targetType === "agent-output" && sourceType !== "agent") {
+    return "agent-output-source-invalid";
+  }
+
   if (targetType === "ai-video" && sourceType !== "video-prompt") {
     return "ai-video-source-invalid";
   }
@@ -152,6 +157,8 @@ export function getCanvasConnectionValidationMessage(
       return "Render akzeptiert nur Bild-, Asset-, KI-Bild-, Crop- oder Adjustment-Input.";
     case "agent-source-invalid":
       return "Agent-Nodes akzeptieren nur Content- und Kontext-Inputs, keine Generierungs-Steuerknoten wie Prompt.";
+    case "agent-output-source-invalid":
+      return "Agent-Ausgabe akzeptiert nur Eingaben von Agent-Nodes.";
     default:
       return "Verbindung ist fuer diese Node-Typen nicht erlaubt.";
   }
diff --git a/lib/canvas-node-catalog.ts b/lib/canvas-node-catalog.ts
index b7c2cb5..25795f7 100644
--- a/lib/canvas-node-catalog.ts
+++ b/lib/canvas-node-catalog.ts
@@ -124,7 +124,8 @@ export const NODE_CATALOG: readonly NodeCatalogEntry[] = [
     type: "agent-output",
     label: "Agent-Ausgabe",
     category: "ai-output",
-    phase: 3,
+    phase: 2,
+    implemented: true,
     systemOutput: true,
     disabledHint: "Wird vom Agenten erzeugt",
   }),
diff --git a/lib/canvas-utils.ts b/lib/canvas-utils.ts
index a7ac1db..5208459 100644
--- a/lib/canvas-utils.ts
+++ b/lib/canvas-utils.ts
@@ -12,6 +12,7 @@ import {
   DEFAULT_DETAIL_ADJUST_DATA,
   DEFAULT_LIGHT_ADJUST_DATA,
 } from "@/lib/image-pipeline/adjustment-types";
+import { DEFAULT_AGENT_MODEL_ID } from "@/lib/agent-models";
 import { DEFAULT_CROP_NODE_DATA } from "@/lib/image-pipeline/crop-node-data";
 
 /**
@@ -121,6 +122,7 @@ const SOURCE_NODE_GLOW_RGB: Record<string, readonly [number, number, number]> =
   crop: [139, 92, 246],
   render: [14, 165, 233],
   agent: [245, 158, 11],
+  "agent-output": [245, 158, 11],
 };
 
 /** Compare: Ziel-Handles blau/smaragd, Quelle compare-out grau (wie in compare-node.tsx). */
@@ -229,6 +231,7 @@ export const NODE_HANDLE_MAP: Record<
   crop: { source: undefined, target: undefined },
   render: { source: undefined, target: undefined },
   agent: { target: "agent-in" },
+  "agent-output": { target: "agent-output-in" },
 };
 
 /**
@@ -281,7 +284,23 @@ export const NODE_DEFAULTS: Record<
   agent: {
     width: 360,
     height: 320,
-    data: { templateId: "campaign-distributor" },
+    data: {
+      templateId: "campaign-distributor",
+      modelId: DEFAULT_AGENT_MODEL_ID,
+      clarificationQuestions: [],
+      clarificationAnswers: {},
+      outputNodeIds: [],
+    },
+  },
+  "agent-output": {
+    width: 360,
+    height: 260,
+    data: {
+      title: "",
+      channel: "",
+      outputType: "",
+      body: "",
+    },
   },
 };
 
diff --git a/tests/agent-node-runtime.test.ts b/tests/agent-node-runtime.test.ts
new file mode 100644
index 0000000..ca67c3e
--- /dev/null
+++ b/tests/agent-node-runtime.test.ts
@@ -0,0 +1,296 @@
+// @vitest-environment jsdom
+
+import React from "react";
+import { act } from "react";
+import { createRoot, type Root } from "react-dom/client";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+const mocks = vi.hoisted(() => ({
+  queueNodeDataUpdate: vi.fn(async () => undefined),
+  runAgent: vi.fn(async () => ({ queued: true })),
+  resumeAgent: vi.fn(async () => ({ queued: true })),
+  toastWarning: vi.fn(),
+  subscription: { tier: "starter" as const },
+  isOffline: false,
+}));
+
+vi.mock("convex/react", () => ({
+  useAction: (reference: unknown) => {
+    if (reference === "agents.resumeAgent") {
+      return mocks.resumeAgent;
+    }
+    return mocks.runAgent;
+  },
+}));
+
+vi.mock("@/convex/_generated/api", () => ({
+  api: {
+    credits: {
+      getSubscription: "credits.getSubscription",
+    },
+    agents: {
+      runAgent: "agents.runAgent",
+      resumeAgent: "agents.resumeAgent",
+    },
+  },
+}));
+
+vi.mock("@/hooks/use-auth-query", () => ({
+  useAuthQuery: () => mocks.subscription,
+}));
+
+vi.mock("@/components/canvas/canvas-sync-context", () => ({
+  useCanvasSync: () => ({
+    queueNodeDataUpdate: mocks.queueNodeDataUpdate,
+    status: { isOffline: mocks.isOffline, isSyncing: false, pendingCount: 0 },
+  }),
+}));
+
+vi.mock("@/lib/toast", () => ({
+  toast: {
+    warning: mocks.toastWarning,
+  },
+}));
+
+vi.mock("@/components/ui/label", () => ({
+  Label: ({ children, htmlFor }: { children: React.ReactNode; htmlFor?: string }) =>
+    React.createElement("label", { htmlFor }, children),
+}));
+
+vi.mock("@/components/ui/select", () => ({
+  Select: ({
+    value,
+    onValueChange,
+    children,
+  }: {
+    value: string;
+    onValueChange: (value: string) => void;
+    children: React.ReactNode;
+  }) =>
+    React.createElement(
+      "select",
+      {
+        "aria-label": "agent-model",
+        value,
+        onChange: (event: Event) => {
+          onValueChange((event.target as HTMLSelectElement).value);
+        },
+      },
+      children,
+    ),
+  SelectTrigger: ({ children }: { children: React.ReactNode }) => children,
+  SelectValue: () => null,
+  SelectContent: ({ children }: { children: React.ReactNode }) => children,
+  SelectItem: ({ children, value }: { children: React.ReactNode; value: string }) =>
+    React.createElement("option", { value }, children),
+}));
+
+vi.mock("@/components/canvas/nodes/base-node-wrapper", () => ({
+  default: ({ children }: { children: React.ReactNode }) => React.createElement("div", null, children),
+}));
+
+vi.mock("@xyflow/react", () => ({
+  Handle: () => null,
+  Position: { Left: "left", Right: "right" },
+}));
+
+import AgentNode from "@/components/canvas/nodes/agent-node";
+
+(globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+
+describe("AgentNode runtime", () => {
+  let container: HTMLDivElement | null = null;
+  let root: Root | null = null;
+
+  beforeEach(() => {
+    mocks.subscription = { tier: "starter" };
+    mocks.isOffline = false;
+    mocks.queueNodeDataUpdate.mockClear();
+    mocks.runAgent.mockClear();
+    mocks.resumeAgent.mockClear();
+    mocks.toastWarning.mockClear();
+  });
+
+  afterEach(() => {
+    if (root) {
+      act(() => {
+        root?.unmount();
+      });
+    }
+    container?.remove();
+    container = null;
+    root = null;
+  });
+
+  it("renders tier-aware model picker, updates node data, and triggers run/resume actions", async () => {
+    container = document.createElement("div");
+    document.body.appendChild(container);
+    root = createRoot(container);
+
+    await act(async () => {
+      root?.render(
+        React.createElement(AgentNode, {
+          id: "agent-1",
+          selected: false,
+          dragging: false,
+          draggable: true,
+          selectable: true,
+          deletable: true,
+          zIndex: 1,
+          isConnectable: true,
+          type: "agent",
+          data: {
+            canvasId: "canvas-1",
+            templateId: "campaign-distributor",
+            modelId: "openai/gpt-5.4-mini",
+            clarificationQuestions: [
+              { id: "audience", prompt: "Target audience?", required: true },
+            ],
+            clarificationAnswers: {},
+          } as Record<string, unknown>,
+          positionAbsoluteX: 0,
+          positionAbsoluteY: 0,
+        }),
+      );
+    });
+
+    const modelSelect = container.querySelector('select[aria-label="agent-model"]');
+    if (!(modelSelect instanceof HTMLSelectElement)) {
+      throw new Error("Agent model select not found");
+    }
+
+    const modelOptionValues = Array.from(modelSelect.querySelectorAll("option")).map(
+      (option) => (option as HTMLOptionElement).value,
+    );
+    expect(modelOptionValues).toContain("openai/gpt-5.4-mini");
+    expect(modelOptionValues).not.toContain("openai/gpt-5.4-pro");
+
+    expect(container.textContent).toContain("GPT-5.4 Mini");
+    expect(container.textContent).toContain("15 Cr");
+    expect(container.textContent).toContain("Channels");
+    expect(container.textContent).toContain("Expected Inputs");
+    expect(container.textContent).toContain("Expected Outputs");
+
+    await act(async () => {
+      modelSelect.value = "openai/gpt-5.4";
+      modelSelect.dispatchEvent(new Event("change", { bubbles: true }));
+    });
+
+    expect(mocks.queueNodeDataUpdate).toHaveBeenCalledWith(
+      expect.objectContaining({
+        nodeId: "agent-1",
+        data: expect.objectContaining({ modelId: "openai/gpt-5.4" }),
+      }),
+    );
+
+    const clarificationInput = container.querySelector('input[name="clarification-audience"]');
+    if (!(clarificationInput instanceof HTMLInputElement)) {
+      throw new Error("Clarification input not found");
+    }
+
+    await act(async () => {
+      const valueSetter = Object.getOwnPropertyDescriptor(
+        HTMLInputElement.prototype,
+        "value",
+      )?.set;
+      valueSetter?.call(clarificationInput, "SaaS founders");
+      clarificationInput.dispatchEvent(new Event("input", { bubbles: true }));
+    });
+
+    expect(mocks.queueNodeDataUpdate).toHaveBeenCalledWith(
+      expect.objectContaining({
+        nodeId: "agent-1",
+        data: expect.objectContaining({
+          clarificationAnswers: expect.objectContaining({ audience: "SaaS founders" }),
+        }),
+      }),
+    );
+
+    const runButton = Array.from(container.querySelectorAll("button")).find((element) =>
+      element.textContent?.includes("Run agent"),
+    );
+    if (!(runButton instanceof HTMLButtonElement)) {
+      throw new Error("Run button not found");
+    }
+
+    await act(async () => {
+      runButton.click();
+    });
+
+    expect(mocks.runAgent).toHaveBeenCalledWith({
+      canvasId: "canvas-1",
+      nodeId: "agent-1",
+      modelId: "openai/gpt-5.4",
+    });
+
+    const submitButton = Array.from(container.querySelectorAll("button")).find((element) =>
+      element.textContent?.includes("Submit clarification"),
+    );
+    if (!(submitButton instanceof HTMLButtonElement)) {
+      throw new Error("Submit clarification button not found");
+    }
+
+    await act(async () => {
+      submitButton.click();
+    });
+
+    expect(mocks.resumeAgent).toHaveBeenCalledWith({
+      canvasId: "canvas-1",
+      nodeId: "agent-1",
+      clarificationAnswers: { audience: "SaaS founders" },
+    });
+  });
+
+  it("warns and skips actions when offline", async () => {
+    mocks.isOffline = true;
+
+    container = document.createElement("div");
+    document.body.appendChild(container);
+    root = createRoot(container);
+
+    await act(async () => {
+      root?.render(
+        React.createElement(AgentNode, {
+          id: "agent-2",
+          selected: false,
+          dragging: false,
+          draggable: true,
+          selectable: true,
+          deletable: true,
+          zIndex: 1,
+          isConnectable: true,
+          type: "agent",
+          data: {
+            canvasId: "canvas-1",
+            templateId: "campaign-distributor",
+            modelId: "openai/gpt-5.4-mini",
+            clarificationQuestions: [{ id: "q1", prompt: "Goal?", required: true }],
+            clarificationAnswers: { q1: "More signups" },
+          } as Record<string, unknown>,
+          positionAbsoluteX: 0,
+          positionAbsoluteY: 0,
+        }),
+      );
+    });
+
+    const runButton = Array.from(container.querySelectorAll("button")).find((element) =>
+      element.textContent?.includes("Run agent"),
+    );
+    const submitButton = Array.from(container.querySelectorAll("button")).find((element) =>
+      element.textContent?.includes("Submit clarification"),
+    );
+
+    if (!(runButton instanceof HTMLButtonElement) || !(submitButton instanceof HTMLButtonElement)) {
+      throw new Error("Runtime action buttons not found");
+    }
+
+    await act(async () => {
+      runButton.click();
+      submitButton.click();
+    });
+
+    expect(mocks.toastWarning).toHaveBeenCalledTimes(2);
+    expect(mocks.runAgent).not.toHaveBeenCalled();
+    expect(mocks.resumeAgent).not.toHaveBeenCalled();
+  });
+});
diff --git a/tests/agent-output-node.test.ts b/tests/agent-output-node.test.ts
new file mode 100644
index 0000000..b002c9d
--- /dev/null
+++ b/tests/agent-output-node.test.ts
@@ -0,0 +1,115 @@
+// @vitest-environment jsdom
+
+import React from "react";
+import { act } from "react";
+import { createRoot, type Root } from "react-dom/client";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+const handleCalls: Array<{ type: string; id?: string }> = [];
+
+vi.mock("@/components/canvas/nodes/base-node-wrapper", () => ({
+  default: ({ children }: { children: React.ReactNode }) => React.createElement("div", null, children),
+}));
+
+vi.mock("@xyflow/react", () => ({
+  Handle: ({ type, id }: { type: string; id?: string }) => {
+    handleCalls.push({ type, id });
+    return React.createElement("div", {
+      "data-handle-type": type,
+      "data-handle-id": id,
+    });
+  },
+  Position: { Left: "left", Right: "right" },
+}));
+
+import AgentOutputNode from "@/components/canvas/nodes/agent-output-node";
+
+(globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+
+describe("AgentOutputNode", () => {
+  let container: HTMLDivElement | null = null;
+  let root: Root | null = null;
+
+  beforeEach(() => {
+    handleCalls.length = 0;
+  });
+
+  afterEach(() => {
+    if (root) {
+      act(() => {
+        root?.unmount();
+      });
+    }
+    container?.remove();
+    container = null;
+    root = null;
+  });
+
+  it("renders title, channel, output type, and body", async () => {
+    container = document.createElement("div");
+    document.body.appendChild(container);
+    root = createRoot(container);
+
+    await act(async () => {
+      root?.render(
+        React.createElement(AgentOutputNode, {
+          id: "agent-output-1",
+          selected: false,
+          dragging: false,
+          draggable: true,
+          selectable: true,
+          deletable: true,
+          zIndex: 1,
+          isConnectable: true,
+          type: "agent-output",
+          data: {
+            title: "Instagram Caption",
+            channel: "instagram-feed",
+            outputType: "caption",
+            body: "A short punchy caption with hashtags",
+            _status: "done",
+          } as Record<string, unknown>,
+          positionAbsoluteX: 0,
+          positionAbsoluteY: 0,
+        }),
+      );
+    });
+
+    expect(container.textContent).toContain("Instagram Caption");
+    expect(container.textContent).toContain("instagram-feed");
+    expect(container.textContent).toContain("caption");
+    expect(container.textContent).toContain("A short punchy caption with hashtags");
+  });
+
+  it("renders input-only handle agent-output-in", async () => {
+    container = document.createElement("div");
+    document.body.appendChild(container);
+    root = createRoot(container);
+
+    await act(async () => {
+      root?.render(
+        React.createElement(AgentOutputNode, {
+          id: "agent-output-2",
+          selected: false,
+          dragging: false,
+          draggable: true,
+          selectable: true,
+          deletable: true,
+          zIndex: 1,
+          isConnectable: true,
+          type: "agent-output",
+          data: {
+            title: "LinkedIn Post",
+            channel: "linkedin",
+            outputType: "post",
+            body: "Body",
+          } as Record<string, unknown>,
+          positionAbsoluteX: 0,
+          positionAbsoluteY: 0,
+        }),
+      );
+    });
+
+    expect(handleCalls).toEqual([{ type: "target", id: "agent-output-in" }]);
+  });
+});
diff --git a/tests/canvas-connection-policy.test.ts b/tests/canvas-connection-policy.test.ts
index 00f0067..8026470 100644
--- a/tests/canvas-connection-policy.test.ts
+++ b/tests/canvas-connection-policy.test.ts
@@ -180,6 +180,26 @@ describe("canvas connection policy", () => {
     ).toBeNull();
   });
 
+  it("allows agent to agent-output", () => {
+    expect(
+      validateCanvasConnectionPolicy({
+        sourceType: "agent",
+        targetType: "agent-output",
+        targetIncomingCount: 0,
+      }),
+    ).toBeNull();
+  });
+
+  it("blocks non-agent sources to agent-output", () => {
+    expect(
+      validateCanvasConnectionPolicy({
+        sourceType: "text",
+        targetType: "agent-output",
+        targetIncomingCount: 0,
+      }),
+    ).toBe("agent-output-source-invalid");
+  });
+
   it("blocks prompt to agent", () => {
     expect(
       validateCanvasConnectionPolicy({
@@ -197,4 +217,10 @@ describe("canvas connection policy", () => {
       "Agent-Nodes akzeptieren nur Content- und Kontext-Inputs, keine Generierungs-Steuerknoten wie Prompt.",
     );
   });
+
+  it("describes invalid agent-output source message", () => {
+    expect(
+      getCanvasConnectionValidationMessage("agent-output-source-invalid"),
+    ).toBe("Agent-Ausgabe akzeptiert nur Eingaben von Agent-Nodes.");
+  });
 });
diff --git a/tests/convex/openrouter-structured-output.test.ts b/tests/convex/openrouter-structured-output.test.ts
new file mode 100644
index 0000000..c16e4b3
--- /dev/null
+++ b/tests/convex/openrouter-structured-output.test.ts
@@ -0,0 +1,189 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+import { generateStructuredObjectViaOpenRouter } from "@/convex/openrouter";
+
+type MockResponseInit = {
+  ok: boolean;
+  status: number;
+  json?: unknown;
+  text?: string;
+};
+
+function createMockResponse(init: MockResponseInit): Response {
+  return {
+    ok: init.ok,
+    status: init.status,
+    json: vi.fn(async () => init.json),
+    text: vi.fn(async () => init.text ?? JSON.stringify(init.json ?? {})),
+  } as unknown as Response;
+}
+
+describe("generateStructuredObjectViaOpenRouter", () => {
+  const fetchMock = vi.fn<typeof fetch>();
+
+  beforeEach(() => {
+    fetchMock.mockReset();
+    vi.stubGlobal("fetch", fetchMock);
+  });
+
+  afterEach(() => {
+    vi.unstubAllGlobals();
+  });
+
+  it("posts chat completion request with strict json_schema and parses response content", async () => {
+    fetchMock.mockResolvedValueOnce(
+      createMockResponse({
+        ok: true,
+        status: 200,
+        json: {
+          choices: [
+            {
+              message: {
+                content: '{"title":"LemonSpace","confidence":0.92}',
+              },
+            },
+          ],
+        },
+      }),
+    );
+
+    const schema = {
+      type: "object",
+      additionalProperties: false,
+      required: ["title", "confidence"],
+      properties: {
+        title: { type: "string" },
+        confidence: { type: "number" },
+      },
+    };
+
+    const result = await generateStructuredObjectViaOpenRouter<{
+      title: string;
+      confidence: number;
+    }>("test-api-key", {
+      model: "openai/gpt-5-mini",
+      messages: [
+        { role: "system", content: "Extract a JSON object." },
+        { role: "user", content: "Title is LemonSpace with confidence 0.92" },
+      ],
+      schemaName: "extract_title",
+      schema,
+    });
+
+    expect(result).toEqual({ title: "LemonSpace", confidence: 0.92 });
+    expect(fetchMock).toHaveBeenCalledTimes(1);
+    expect(fetchMock).toHaveBeenCalledWith(
+      "https://openrouter.ai/api/v1/chat/completions",
+      expect.objectContaining({
+        method: "POST",
+        headers: expect.objectContaining({
+          Authorization: "Bearer test-api-key",
+          "Content-Type": "application/json",
+          "HTTP-Referer": "https://app.lemonspace.io",
+          "X-Title": "LemonSpace",
+        }),
+      }),
+    );
+
+    const firstCallArgs = fetchMock.mock.calls[0];
+    const init = firstCallArgs?.[1] as RequestInit | undefined;
+    const bodyRaw = init?.body;
+    const body = JSON.parse(typeof bodyRaw === "string" ? bodyRaw : "{}");
+
+    expect(body).toMatchObject({
+      model: "openai/gpt-5-mini",
+      messages: [
+        { role: "system", content: "Extract a JSON object." },
+        { role: "user", content: "Title is LemonSpace with confidence 0.92" },
+      ],
+      response_format: {
+        type: "json_schema",
+        json_schema: {
+          name: "extract_title",
+          strict: true,
+          schema,
+        },
+      },
+    });
+  });
+
+  it("throws ConvexError code when response content is missing", async () => {
+    fetchMock.mockResolvedValueOnce(
+      createMockResponse({
+        ok: true,
+        status: 200,
+        json: {
+          choices: [
+            {
+              message: {},
+            },
+          ],
+        },
+      }),
+    );
+
+    await expect(
+      generateStructuredObjectViaOpenRouter("test-api-key", {
+        model: "openai/gpt-5-mini",
+        messages: [{ role: "user", content: "hello" }],
+        schemaName: "test_schema",
+        schema: { type: "object" },
+      }),
+    ).rejects.toMatchObject({
+      data: { code: "OPENROUTER_STRUCTURED_OUTPUT_MISSING_CONTENT" },
+    });
+  });
+
+  it("throws ConvexError code when response content is invalid JSON", async () => {
+    fetchMock.mockResolvedValueOnce(
+      createMockResponse({
+        ok: true,
+        status: 200,
+        json: {
+          choices: [
+            {
+              message: {
+                content: "not valid json",
+              },
+            },
+          ],
+        },
+      }),
+    );
+
+    await expect(
+      generateStructuredObjectViaOpenRouter("test-api-key", {
+        model: "openai/gpt-5-mini",
+        messages: [{ role: "user", content: "hello" }],
+        schemaName: "test_schema",
+        schema: { type: "object" },
+      }),
+    ).rejects.toMatchObject({
+      data: { code: "OPENROUTER_STRUCTURED_OUTPUT_INVALID_JSON" },
+    });
+  });
+
+  it("throws ConvexError code when OpenRouter responds with non-ok status", async () => {
+    fetchMock.mockResolvedValueOnce(
+      createMockResponse({
+        ok: false,
+        status: 503,
+        text: "service unavailable",
+      }),
+    );
+
+    await expect(
+      generateStructuredObjectViaOpenRouter("test-api-key", {
+        model: "openai/gpt-5-mini",
+        messages: [{ role: "user", content: "hello" }],
+        schemaName: "test_schema",
+        schema: { type: "object" },
+      }),
+    ).rejects.toMatchObject({
+      data: {
+        code: "OPENROUTER_STRUCTURED_OUTPUT_HTTP_ERROR",
+        status: 503,
+      },
+    });
+  });
+});
diff --git a/tests/lib/agent-models.test.ts b/tests/lib/agent-models.test.ts
new file mode 100644
index 0000000..89df726
--- /dev/null
+++ b/tests/lib/agent-models.test.ts
@@ -0,0 +1,61 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  AGENT_MODELS,
+  DEFAULT_AGENT_MODEL_ID,
+  getAgentModel,
+  getAvailableAgentModels,
+  isAgentModelAvailableForTier,
+} from "@/lib/agent-models";
+import { NODE_DEFAULTS } from "@/lib/canvas-utils";
+
+describe("agent models registry", () => {
+  it("contains approved models in stable order", () => {
+    expect(Object.keys(AGENT_MODELS)).toEqual([
+      "openai/gpt-5.4-nano",
+      "openai/gpt-5.4-mini",
+      "openai/gpt-5.4",
+      "openai/gpt-5.4-pro",
+    ]);
+    expect(DEFAULT_AGENT_MODEL_ID).toBe("openai/gpt-5.4-mini");
+  });
+
+  it("resolves model lookup and pricing", () => {
+    expect(getAgentModel("openai/gpt-5.4-nano")?.creditCost).toBe(6);
+    expect(getAgentModel("openai/gpt-5.4-mini")?.creditCost).toBe(15);
+    expect(getAgentModel("openai/gpt-5.4")?.creditCost).toBe(38);
+    expect(getAgentModel("openai/gpt-5.4-pro")?.creditCost).toBe(180);
+    expect(getAgentModel("unknown-model")).toBeUndefined();
+  });
+
+  it("filters models by tier", () => {
+    expect(getAvailableAgentModels("free").map((model) => model.id)).toEqual([]);
+    expect(getAvailableAgentModels("starter").map((model) => model.id)).toEqual([
+      "openai/gpt-5.4-nano",
+      "openai/gpt-5.4-mini",
+      "openai/gpt-5.4",
+    ]);
+    expect(getAvailableAgentModels("max").map((model) => model.id)).toEqual([
+      "openai/gpt-5.4-nano",
+      "openai/gpt-5.4-mini",
+      "openai/gpt-5.4",
+      "openai/gpt-5.4-pro",
+    ]);
+  });
+
+  it("guards access by tier", () => {
+    expect(isAgentModelAvailableForTier("starter", "openai/gpt-5.4")).toBe(true);
+    expect(isAgentModelAvailableForTier("starter", "openai/gpt-5.4-pro")).toBe(false);
+    expect(isAgentModelAvailableForTier("max", "openai/gpt-5.4-pro")).toBe(true);
+  });
+
+  it("uses the registry default in agent node defaults", () => {
+    expect(NODE_DEFAULTS.agent?.data).toMatchObject({
+      templateId: "campaign-distributor",
+      modelId: DEFAULT_AGENT_MODEL_ID,
+      clarificationQuestions: [],
+      clarificationAnswers: {},
+      outputNodeIds: [],
+    });
+  });
+});
diff --git a/tests/lib/agent-run-contract.test.ts b/tests/lib/agent-run-contract.test.ts
new file mode 100644
index 0000000..d509f0f
--- /dev/null
+++ b/tests/lib/agent-run-contract.test.ts
@@ -0,0 +1,96 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  areClarificationAnswersComplete,
+  normalizeAgentOutputDraft,
+  type AgentClarificationAnswerMap,
+  type AgentClarificationQuestion,
+} from "@/lib/agent-run-contract";
+
+describe("agent run contract helpers", () => {
+  describe("areClarificationAnswersComplete", () => {
+    it("returns true when every required question has a non-empty answer", () => {
+      const questions: AgentClarificationQuestion[] = [
+        { id: "goal", prompt: "What is the goal?", required: true },
+        { id: "tone", prompt: "Preferred tone?", required: false },
+        { id: "audience", prompt: "Who is the audience?", required: true },
+      ];
+
+      const answers: AgentClarificationAnswerMap = {
+        goal: "Generate launch captions",
+        audience: "SaaS founders",
+      };
+
+      expect(areClarificationAnswersComplete(questions, answers)).toBe(true);
+    });
+
+    it("returns false when a required question is missing", () => {
+      const questions: AgentClarificationQuestion[] = [
+        { id: "goal", prompt: "What is the goal?", required: true },
+        { id: "audience", prompt: "Who is the audience?", required: true },
+      ];
+
+      const answers: AgentClarificationAnswerMap = {
+        goal: "Generate launch captions",
+      };
+
+      expect(areClarificationAnswersComplete(questions, answers)).toBe(false);
+    });
+
+    it("returns false when required answers are blank after trimming", () => {
+      const questions: AgentClarificationQuestion[] = [
+        { id: "goal", prompt: "What is the goal?", required: true },
+      ];
+
+      const answers: AgentClarificationAnswerMap = {
+        goal: "   ",
+      };
+
+      expect(areClarificationAnswersComplete(questions, answers)).toBe(false);
+    });
+  });
+
+  describe("normalizeAgentOutputDraft", () => {
+    it("trims draft fields and keeps non-empty values", () => {
+      const normalized = normalizeAgentOutputDraft({
+        title: "  Launch Caption Pack  ",
+        channel: "  Instagram Feed  ",
+        outputType: "  caption-package  ",
+        body: "  3 variants with hook-first copy.  ",
+      });
+
+      expect(normalized).toEqual({
+        title: "Launch Caption Pack",
+        channel: "Instagram Feed",
+        outputType: "caption-package",
+        body: "3 variants with hook-first copy.",
+      });
+    });
+
+    it("uses safe fallback values and guarantees body string", () => {
+      const normalized = normalizeAgentOutputDraft({
+        title: "   ",
+        channel: "",
+        outputType: "   ",
+      });
+
+      expect(normalized).toEqual({
+        title: "Untitled",
+        channel: "general",
+        outputType: "text",
+        body: "",
+      });
+    });
+
+    it("coerces non-string body values to empty string", () => {
+      const normalized = normalizeAgentOutputDraft({
+        title: "Recap",
+        channel: "Email",
+        outputType: "summary",
+        body: null as unknown as string,
+      });
+
+      expect(normalized.body).toBe("");
+    });
+  });
+});