I built a crypto research agent in ~150 lines of Python. Here's the code (runs free, no signup)

"""A crypto research agent: reads market APIs and web pages through a proxy. pip install anthropic requests beautifulsoup4 export ANTHROPIC_API_KEY=... python crypto_agent.py "Which of today's top 5 CoinGecko gainers trade on DexScreener with >$1M liquidity?" Proxy (PROXY_URL): default http://ws.solproxy.net:8501 free pool, no signup (1 GB/day per IP) free acct http://free:TOKEN@ws.solproxy.net:8501 free account, 25 GB/month paid http://USERNAME:TOKEN@ws.solproxy.net:8500 rotating residential """ import json import os import sys import time from urllib.parse import urljoin import anthropic import requests from bs4 import BeautifulSoup PROXY_URL = os.getenv("PROXY_URL", "http://ws.solproxy.net:8501") # "" = no proxy PROXIES = {"http": PROXY_URL, "https": PROXY_URL} if PROXY_URL else None HEADERS = {"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 " "(KHTML, like Gecko) Chrome/130.0 Safari/537.36", "Accept-Language": "en-US,en;q=0.9"} BLOCKED = {403, 429, 503} def _get(url: str): """GET with retries on blocks/rate limits. Each retry goes out through the proxy again (a new exit IP on a rotating pool) after a short back-off.""" last = None for attempt in range(3): try: r = requests.get(url, headers=HEADERS, proxies=PROXIES, timeout=30) except requests.RequestException as e: last = f"network error: {e}" else: if r.status_code not in BLOCKED: return r, None last = f"HTTP {r.status_code} (blocked/rate-limited)" time.sleep(1.5 * (attempt + 1)) return None, last def fetch_json(url: str, max_chars: int = 12000) -> dict: """Call a public JSON API (CoinGecko, DexScreener, an exchange's REST API).""" r, err = _get(url) if err: return {"url": url, "error": err} if r.status_code >= 400: return {"url": url, "error": f"HTTP {r.status_code}"} try: data = r.json() except ValueError: return {"url": url, "error": "response is not JSON"} return {"url": url, "json": json.dumps(data)[:max_chars]} def fetch_page(url: str, max_chars: int = 8000) -> dict: """Download a page and return its title, readable text and links.""" r, err = _get(url) if err: return {"url": url, "error": err} if r.status_code >= 400: return {"url": url, "error": f"HTTP {r.status_code}"} soup = BeautifulSoup(r.text, "html.parser") for tag in soup(["script", "style", "noscript", "svg", "nav", "footer"]): tag.decompose() text = " ".join(soup.get_text(" ").split()) links = [] for a in soup.find_all("a", href=True): href = urljoin(url, a["href"]) if href.startswith("http") and href not in links: links.append(href) return {"url": url, "title": soup.title.string.strip() if soup.title and soup.title.string else "", "text": text[:max_chars], "links": links[:40]} TOOLS = [{ "name": "fetch_page", "description": "Fetch a web page and return its title, main text (truncated) and up to " "40 absolute links found on it. Use the links to go deeper.", "input_schema": { "type": "object", "properties": {"url": {"type": "string", "description": "Absolute http(s) URL"}}, "required": ["url"], "additionalProperties": False, }, "strict": True, }, { "name": "fetch_json", "description": "Call a public JSON API and return the body (truncated). Useful endpoints: " "https://api.coingecko.com/api/v3/search/trending, " "https://api.coingecko.com/api/v3/coins/markets?vs_currency=usd&order=market_cap_desc&per_page=50, " "https://api.coingecko.com/api/v3/simple/price?ids=bitcoin,ethereum&vs_currencies=usd&include_24hr_change=true, " "https://api.dexscreener.com/latest/dex/search?q=<token symbol or address>.", "input_schema": { "type": "object", "properties": {"url": {"type": "string", "description": "Absolute https URL of the API call"}}, "required": ["url"], "additionalProperties": False, }, "strict": True, }] TOOL_FUNCS = {"fetch_page": fetch_page, "fetch_json": fetch_json} SYSTEM = ("You are a crypto market research agent. Prefer fetch_json on public APIs for " "numbers (prices, volume, liquidity) and fetch_page for announcements, docs and " "news. Make as few calls as you need, stop as soon as you can answer, give the " "numbers with the time you read them, and cite every URL you used. " "This is research, not financial advice: say so if asked what to buy.") def run(question: str, max_steps: int = 12) -> str: client = anthropic.Anthropic() messages = [{"role": "user", "content": question}] for _ in range(max_steps): response = client.beta.messages.create( model="claude-opus-5-5", max_tokens=16000, system=SYSTEM, tools=TOOLS, messages=messages, betas=["server-side-fallback-2026-07-01"], fallbacks="default", ) if response.stop_reason in ("end_turn", "refusal", "max_tokens"): return "".join(b.text for b in response.content if b.type == "text") messages.append({"role": "assistant", "content": response.content}) if response.stop_reason == "pause_turn": continue results = [] for block in response.content: if block.type == "tool_use": print(f" -> {block.name} {block.input['url']}", file=sys.stderr) page = TOOL_FUNCS[block.name](block.input["url"]) results.append({"type": "tool_result", "tool_use_id": block.id, "content": json.dumps(page), "is_error": "error" in page}) messages.append({"role": "user", "content": results}) return "Stopped: step limit reached." if __name__ == "__main__": print(run(" ".join(sys.argv[1:]) or "What is trending on CoinGecko right now, and what are " "the price and 24h change of the top 3 trending coins?")) 

pip install anthropic requests beautifulsoup4 export ANTHROPIC_API_KEY=sk-ant-... python crypto_agent.py "What is trending on CoinGecko right now? Price and 24h change of the top 3, and their DexScreener liquidity." 

 -> fetch_json https://api.coingecko.com/api/v3/search/trending -> fetch_json https://api.coingecko.com/api/v3/simple/price?ids=...&vs_currencies=usd&include_24hr_change=true -> fetch_json https://api.dexscreener.com/latest/dex/search?q=...