autoreg-skills-max/skills/conol-automation/references/httpx-cookie-pitfall.md

httpx Concurrent Client Cookie Corruption

Symptom

All 30 parallel requests return HTTP 401, but individual tests succeed.

Root Cause

Sharing ONE httpx.AsyncClient instance across multiple concurrent asyncio tasks corrupts cookie handling. httpx reuses connection pools and cookie jars that are not thread/async-safe when multiple tasks set different cookies.

Wrong Pattern

# ❌ Creates one shared client — cookies from different accounts mix up
async def main():
    async with httpx.AsyncClient(timeout=httpx.Timeout(30)) as shared_client:
        # All 30 concurrent tasks use the SAME client
        tasks = [test_account(shared_client, acc) for acc in accounts]
        await asyncio.gather(*tasks)

async def test_account(client, acc):
    # Setting cookies on the shared client
    client.cookies = {name: value}  # Gets overwritten by other tasks!
    r = await client.post(...)

Correct Pattern

# ✅ Each concurrent task creates its OWN client
async def test_account(acc):
    cookies = load_cookies(acc['cookies_path'])
    async with httpx.AsyncClient(cookies=cookies, timeout=httpx.Timeout(30)) as client:
        r = await client.post(...)

async def main():
    tasks = [test_account(acc) for acc in accounts]
    await asyncio.gather(*tasks)

Concurrency Control

Use asyncio.Semaphore(N) to limit concurrent connections:

sem = asyncio.Semaphore(3)

async def bounded(acc):
    async with sem:
        return await test_account(acc)

results = await asyncio.gather(*[bounded(a) for a in accounts])

Detection

If you see HTTP 401 on all requests in parallel but HTTP 201 on individual sequential requests, this is almost certainly the shared client issue.