OAuth3 Demo: Constrained Claude Query (template-based delegation)

constrained-claude-query.ts

// @skill Constrained Claude Query
// @description Template-based Anthropic API delegation - Agent provides word (≤20 chars) for character counting
// @secrets ANTHROPIC_API_KEY
// @network api.anthropic.com
// @timeout 30

const WORD = Deno.env.get("WORD");
const ANTHROPIC_API_KEY = Deno.env.get("ANTHROPIC_API_KEY");

if (!WORD) {
  console.error("Error: WORD parameter required");
  Deno.exit(1);
}

if (!ANTHROPIC_API_KEY) {
  console.error("Error: ANTHROPIC_API_KEY secret required");
  Deno.exit(1);
}

// Sanitizer: Enforce 20 character limit
if (WORD.length > 20) {
  console.error(`Error: WORD must be ≤20 characters (got ${WORD.length})`);
  Deno.exit(1);
}

// Sanitizer: Only allow alphanumeric + basic punctuation (no newlines, control chars)
if (!/^[a-zA-Z0-9\s\-_.,!?]+$/.test(WORD)) {
  console.error("Error: WORD contains invalid characters");
  Deno.exit(1);
}

// Template: Agent can only fill in the suffix
const TEMPLATE = "Count the characters in the following word: ";
const fullPrompt = TEMPLATE + WORD;

console.log(`📝 Prompt: "${fullPrompt}"`);
console.log(`🔒 Word length: ${WORD.length}/20 chars`);
console.log(`\n🤖 Calling Anthropic API...\n`);

try {
  const response = await fetch("https://api.anthropic.com/v1/messages", {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "x-api-key": ANTHROPIC_API_KEY,
      "anthropic-version": "2023-06-01",
    },
    body: JSON.stringify({
      model: "claude-3-5-haiku-20241022",
      max_tokens: 100,
      messages: [
        {
          role: "user",
          content: fullPrompt,
        },
      ],
    }),
  });

  if (!response.ok) {
    const error = await response.text();
    console.error(`API Error ${response.status}: ${error}`);
    Deno.exit(1);
  }

  const data = await response.json();
  const content = data.content[0]?.text || "(no response)";

  console.log(`✅ Claude's response:\n${content}`);
  console.log(`\n📊 Tokens used: ${data.usage.input_tokens} in, ${data.usage.output_tokens} out`);
} catch (error) {
  console.error(`Network error: ${error.message}`);
  Deno.exit(1);
}