[Bug]: Docker API JSON serialization fails for ProxyConfig

[SohamKukreti]

crawl4ai version

0.7.7

Expected Behavior

When using proxy_config with BrowserConfig, the configuration should be serializable to JSON for use with the Docker API server's crawler pool.

The BrowserConfig.to_dict() methods should properly serialize ProxyConfig and GeolocationConfig objects by calling their respective to_dict() methods.

Current Behavior

When passing proxy_config to BrowserConfig, the Docker API server crashes with:

TypeError: Object of type ProxyConfig is not JSON serializable

This occurs in crawler_pool.py when trying to generate a configuration signature:

payload = json.dumps(cfg.to_dict(), sort_keys=True, separators=(",",":"))

The issue is that BrowserConfig.to_dict() directly assign ProxyConfig and GeolocationConfig objects instead of converting them to dictionaries first.

Is this reproducible?

Yes

Inputs Causing the Bug

URL: https://example.com/
Request to the docker server:
{
        "urls": ["https://example.com"],
        "browser_config": {
            "headless": True,
            "proxy_config": {
                "server": "http://proxy.example.com:8080",
                "username": "user",
                "password": "pass"
            }
        }
    }

Steps to Reproduce

Send request to docker server with proxy_config in browser_config

Code snippets

# Reproduction code
import requests

response = requests.post(
    "http://localhost:11235/crawl",
    json={
        "urls": ["https://example.com"],
        "browser_config": {
            "headless": True,
            "proxy_config": {
                "server": "http://proxy.example.com:8080",
                "username": "user",
                "password": "pass"
            }
        }
    }
)

OS

Linux

Python version

3.10

Browser

No response

Browser version

No response

Error logs & Screenshots (if applicable)

[INIT].... → Crawl4AI 0.7.7
INFO: Application startup complete.
INFO: Uvicorn running on http://0.0.0.0:11235 (Press CTRL+C to quit)
2025-11-21 20:15:19,049 - api - ERROR - Crawl error: Object of type ProxyConfig is not JSON serializable
Traceback (most recent call last):
File "/home/soham/Documents/crawl4ai/crawl4ai/deploy/docker/api.py", line 550, in handle_crawl_request
crawler = await get_crawler(browser_config)
File "/home/soham/Documents/crawl4ai/crawl4ai/deploy/docker/crawler_pool.py", line 36, in get_crawler
sig = _sig(cfg)
File "/home/soham/Documents/crawl4ai/crawl4ai/deploy/docker/crawler_pool.py", line 27, in _sig
payload = json.dumps(cfg.to_dict(), sort_keys=True, separators=(",",":"))
File "/usr/lib64/python3.10/json/init.py", line 238, in dumps
**kw).encode(obj)
File "/usr/lib64/python3.10/json/encoder.py", line 199, in encode
chunks = self.iterencode(o, _one_shot=True)
File "/usr/lib64/python3.10/json/encoder.py", line 257, in iterencode
return _iterencode(o, 0)
File "/usr/lib64/python3.10/json/encoder.py", line 179, in default
raise TypeError(f'Object of type {o.class.name} '
TypeError: Object of type ProxyConfig is not JSON serializable

[SohamKukreti]

Potential Fix

The fix requires modifying crawl4ai/async_configs.py to properly serialize ProxyConfig and GeolocationConfig objects in the to_dict() methods.
Changes Required:

1. In BrowserConfig.to_dict() method (around line 601):

# BEFORE (line 601)
"proxy_config": self.proxy_config,

# AFTER
"proxy_config": self.proxy_config.to_dict() if self.proxy_config else None,