Add ERC-8021 builder codes, fix LLM JSON parsing, context truncation

- base-chain.ts: new module for Base chain ERC-8021 builder code
  attribution — records paper authors on Base transactions
- content-generator.ts: robust JSON extraction handling think tags,
  code fences, and bracket scanning; truncate paper context to 24K
  chars to prevent 413 payload errors
- lesson-watcher.ts: integrate Base chain attribution after publishing
- server.ts: optional BaseChain init from BASE_RPC_URL env var
- Add ethers dependency for Base chain transactions

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: 2 people

cogito/.env.example

@@ -1,16 +1,20 @@
-# Required: Anthropic API key for Claude Code
-ANTHROPIC_API_KEY=sk-ant-...
-
-# AIN blockchain node (inside docker network)
+# AIN blockchain node
 AIN_PROVIDER_URL=http://ain-blockchain:8080
 
-# AIN wallet private key (same key as the node)
+# AIN wallet private key
 AIN_PRIVATE_KEY=b22c95ffc4a5c096f7d7d0487ba963ce6ac945bdc91c79b64ce209de289bec96
 
-# Base chain (for ERC-8004/8021 transactions)
-BASE_RPC_URL=https://mainnet.base.org
-BASE_PRIVATE_KEY=${AIN_PRIVATE_KEY}
+# vLLM endpoint (local LLM for content generation)
+VLLM_URL=http://vllm:8000
+VLLM_MODEL=Qwen/Qwen3-32B-AWQ
+
+# Lesson watcher
+POLL_INTERVAL_MS=30000
+CONTENT_PRICE=0.005
+
+# x402 server port
+X402_PORT=3402
 
-# Exploration settings
-THINK_INTERVAL_MS=120000
-MAX_PAPERS_PER_CYCLE=5
+# Base chain — optional, enables ERC-8021 builder code attribution
+# BASE_RPC_URL=https://mainnet.base.org
+# BASE_PRIVATE_KEY=your_base_private_key

cogito/package-lock.json

@@ -11,11 +11,12 @@
   },
   "dependencies": {
     "@ainblockchain/ain-js": "^1.14.0",
-    "dotenv": "^16.4.0"
+    "dotenv": "^16.4.0",
+    "ethers": "^6.16.0"
   },
   "devDependencies": {
-    "typescript": "^5.4.0",
     "@types/node": "^22.0.0",
-    "tsx": "^4.7.0"
+    "tsx": "^4.7.0",
+    "typescript": "^5.4.0"
   }
 }

cogito/package.json

@@ -0,0 +1,120 @@
+/**
+ * Base chain integration for the Cogito container.
+ * ERC-8021 builder codes attribute paper authors on Base transactions.
+ *
+ * Only active when BASE_RPC_URL and BASE_PRIVATE_KEY are set.
+ */
+
+import { ethers } from 'ethers';
+import { Paper } from './paper-discovery.js';
+
+// ERC-8021 constants
+const ERC_MARKER = '80218021802180218021802180218021';
+const SCHEMA_ID = '00';
+const COGITO_BUILDER_CODE = 'cogito_node';
+
+interface AuthorAttribution {
+  type: 'arxiv' | 'github' | 'doi' | 'custom';
+  identifier: string;
+}
+
+/**
+ * Encode builder codes into an ERC-8021 hex suffix.
+ */
+function encodeBuilderCodes(codes: string[]): string {
+  if (codes.length === 0) throw new Error('At least one builder code is required');
+
+  const codesString = codes.join(',');
+  const codesBytes = Buffer.from(codesString, 'ascii');
+
+  if (codesBytes.length > 255) {
+    throw new Error(`Builder codes total length ${codesBytes.length} exceeds 255 bytes`);
+  }
+
+  const codesLengthHex = codesBytes.length.toString(16).padStart(2, '0');
+  const codesHex = codesBytes.toString('hex');
+
+  return codesLengthHex + codesHex + SCHEMA_ID + ERC_MARKER;
+}
+
+/**
+ * Build author attributions from paper metadata.
+ */
+function buildAuthorCodes(paper: Paper): AuthorAttribution[] {
+  const attributions: AuthorAttribution[] = [];
+
+  if (paper.arxivId) {
+    attributions.push({ type: 'arxiv', identifier: paper.arxivId });
+  }
+
+  if (paper.codeUrl) {
+    // Extract owner/repo from GitHub URL
+    const match = paper.codeUrl.match(/github\.com\/([^/]+\/[^/]+)/);
+    if (match) {
+      attributions.push({ type: 'github', identifier: match[1] });
+    }
+  }
+
+  // First author's last name
+  if (paper.authors.length > 0) {
+    const lastName = paper.authors[0].split(' ').pop()?.toLowerCase();
+    if (lastName) {
+      attributions.push({ type: 'custom', identifier: lastName });
+    }
+  }
+
+  return attributions;
+}
+
+export class BaseChain {
+  private provider: ethers.JsonRpcProvider;
+  private signer: ethers.Wallet;
+
+  constructor(rpcUrl: string, privateKey: string) {
+    this.provider = new ethers.JsonRpcProvider(rpcUrl);
+    this.signer = new ethers.Wallet(privateKey, this.provider);
+  }
+
+  /**
+   * Record a Base chain transaction with ERC-8021 builder codes
+   * attributing the original paper authors whose work informed the content.
+   */
+  async recordAttribution(
+    topicPath: string,
+    papers: Paper[],
+  ): Promise<string | null> {
+    try {
+      // Build codes: agent + paper authors
+      const codes = [COGITO_BUILDER_CODE];
+      for (const paper of papers.slice(0, 3)) {
+        const authorCodes = buildAuthorCodes(paper);
+        for (const ac of authorCodes) {
+          codes.push(`${ac.type}_${ac.identifier}`);
+        }
+      }
+
+      // Encode topic as data payload
+      const topicHex = Buffer.from(`cogito:enrich:${topicPath}`).toString('hex');
+      const suffix = encodeBuilderCodes(codes);
+      const data = `0x${topicHex}${suffix}`;
+
+      // Self-transfer with builder code attribution
+      const tx = await this.signer.sendTransaction({
+        to: this.signer.address,
+        value: 0,
+        data,
+      });
+
+      const authorCount = codes.length - 1;
+      console.log(`[Base] Tx recorded: ${tx.hash} (topic: ${topicPath}, codes: ${COGITO_BUILDER_CODE}+${authorCount} authors)`);
+      return tx.hash;
+    } catch (err: any) {
+      console.error(`[Base] Failed to record attribution: ${err.message}`);
+      return null;
+    }
+  }
+
+  getAddress(): string {
+    return this.signer.address;
+  }
+}