1// OpenAI node: Generate execution plan
2const planPrompt = `
3You are a task planning agent. Break down this task into executable steps.
4
5Task: "${$json.task}"
6
7Available tools:
8- web_search: Search the internet for information
9- calculator: Perform calculations
10- database_query: Query a database
11- send_email: Send an email
12- create_document: Create a document
13- http_request: Call any API
14
15Create a step-by-step plan:
161. Each step should use exactly one tool
172. Steps should be in correct order
183. Include expected output for each step
194. Include fallback if a step fails
20
21Return JSON:
22{
23  "task": "original task",
24  "steps": [
25    {
26      "step": 1,
27      "action": "tool_name",
28      "description": "what this step does",
29      "input": "what to send to the tool",
30      "expectedOutput": "what to expect back",
31      "fallback": "what to do if this fails"
32    }
33  ],
34  "estimatedTime": "total time estimate"
35}`;

1// Code node: Step executor (inside Loop)
2const step = $json.currentStep;
3const previousResults = $json.previousResults || [];
4
5// Build context from previous steps
6const context = previousResults.map(r => 
7  `Step ${r.step}: ${r.result}`
8).join('\n');
9
10// Route to appropriate tool
11let toolConfig;
12switch (step.action) {
13  case "web_search":
14    toolConfig = {
15      route: "http_request",
16      url: `https://api.search.com/search?q=${encodeURIComponent(step.input)}`,
17      method: "GET"
18    };
19    break;
20  case "database_query":
21    toolConfig = {
22      route: "database",
23      query: step.input
24    };
25    break;
26  case "send_email":
27    toolConfig = {
28      route: "email",
29      to: step.input.to,
30      subject: step.input.subject,
31      body: step.input.body
32    };
33    break;
34  default:
35    toolConfig = { route: "code", input: step.input };
36}
37
38return { json: { ...step, toolConfig, context } };

1// When a step fails, re-plan remaining steps
2const replanPrompt = `
3Original plan:
4${JSON.stringify($json.originalPlan, null, 2)}
5
6Completed steps:
7${$json.completedSteps.map(s => `Step ${s.step}: ${s.status} - ${s.result}`).join('\n')}
8
9Failed step:
10Step ${$json.failedStep.step}: ${$json.failedStep.error}
11
12Create a revised plan for the remaining work.
13Consider what was already done and the failure reason.
14
15Return JSON with revised remaining steps.`;

1// ReAct: Agent reasons about what to do, acts, observes, repeats
2
3const reactPrompt = `
4You are a ReAct agent. For each step:
51. Thought: Reason about what to do
62. Action: Choose a tool and input
73. Observation: Process the result
84. Repeat until task is complete
9
10Task: ${$json.task}
11
12Available Actions: search, calculate, lookup, respond
13
14Format:
15Thought: [reasoning]
16Action: [tool_name] [input]
17Observation: [result after execution]
18... repeat ...
19Thought: I now have enough information
20Action: respond [final answer]
21`;
22
23// n8n implements this via Agent node loops
24// Agent node with Tools = ReAct pattern

1// Research Agent implementation
2// Step 1: Plan search queries
3const planPrompt = `
4For the research question: "${$json.question}"
5Generate 3-5 specific search queries that would help answer this.
6Return as JSON array: ["query1", "query2", ...]`;
7
8// Step 2: Execute searches (Loop)
9// Step 3: Analyze each result (AI)
10// Step 4: Synthesize into report (AI with all context)

1// Code node: Agent error handler
2const maxRetries = 3;
3const currentRetry = $json.retryCount || 0;
4
5if ($json.stepResult.error) {
6  if (currentRetry < maxRetries) {
7    // Retry with modified approach
8    return {
9      json: {
10        action: "retry",
11        retryCount: currentRetry + 1,
12        modifiedInput: `Previous attempt failed: ${$json.stepResult.error}. Try a different approach.`
13      }
14    };
15  } else {
16    // Skip and continue with fallback
17    return {
18      json: {
19        action: "skip",
20        result: $json.currentStep.fallback || "Step skipped due to errors"
21      }
22    };
23  }
24}
25
26// Success
27return { json: { action: "continue", result: $json.stepResult.data } };