Blackbox.ai Registration & API

Registration Flow

Blackbox.ai (app.blackbox.ai) — multi-agent orchestration platform with 48+ AI models, paid API access.

Signup page: https://app.blackbox.ai/signup
NO CAPTCHA on the signup form — just email + password
Next.js server action: The form submits via POST /signup with multipart/form-data and text/x-component accept header
Response: {"type":"success","resultCode":"USER_CREATED"} (RSC format)
NO browser needed for the POST itself, but the next-action header is dynamically generated from the page — cannot be hardcoded for HTTP-only signup

The signup endpoint is POST https://app.blackbox.ai/signup with body:

------WebKitFormBoundary...
Content-Disposition: form-data; name="1_email"

email@domain.com
------WebKitFormBoundary...
Content-Disposition: form-data; name="1_password"

password
------WebKitFormBoundary...
Content-Disposition: form-data; name="0"

["$undefined","$K1"]
------WebKitFormBoundary...--

Required headers:

Content-Type: multipart/form-data; boundary=...
next-action: <40-char hex from page> — dynamically generated, not in initial HTML
Accept: text/x-component
Origin: https://app.blackbox.ai

Without a valid next-action header, the server returns a generic 400 error. The action ID is client-side generated and changes per session.

Email Verification (BLOCKER)

After signup, sent to "Verify your email" page (6-digit code)
t-online.de emails DO NOT receive verification emails from Blackbox — tested with multiple accounts (asmoky, kevinfischer05, daniel.brueck, eric.foeller)
Gmail also does not receive — tested with [REDACTED-NAME]+bb1@gmail.com (no email found in inbox)
Email may be delayed or filtered by domain. Alternative email providers (Outlook, ProtonMail) untested.
Login returns 500 Internal Server Error when account is unverified — verification is a hard requirement

Google OAuth (BLOCKED)

Google sign-in button on login/signup pages
Google blocks OAuth for Blackbox via CDP: navigates to accounts.google.com/v3/signin/rejected with "browser or app may be unsafe"
This happens even in the user's real Chrome via CDP (not just headless)
Google client_id: 985058387028-iaa60lr5e586kvhjp085qcojv3jv2p7h.apps.googleusercontent.com

API Access

Endpoint

API base: https://enterprise.blackbox.ai/chat/completions
OpenAI-compatible format
Paid tier only — requires verified account with billing

Models (48+)

Documented at https://www.blackbox.ai/models. Notable models:

z-ai/glm-5.2 ($1.40/$4.40 per MTok)
deepseek/deepseek-v4-pro ($0.44/$0.87)
anthropic/claude-opus-4.8 ($5/$25)
openai/gpt-5.5 ($5/$30)
moonshotai/kimi-k2.7-code ($0.74/$3.50)
nvidia/nemotron-3-ultra ($0.32/$0.80)
google/gemini-3.5-flash ($1.50/$9)
x-ai/grok-4.3 ($1.25/$2.50)
anthropic/claude-sonnet-5 ($3/$15)
anthropic/claude-opus-5 ($15/$75)

Integration Strategy

Working Approach

Use CDP Chrome to fill signup form (no CAPTCHA — works)
Account is created immediately (USER_CREATED)
Verification email — unsolved for t-online.de and Gmail
Alternative: use a different email provider that Blackbox accepts

# Navigate to signup
page.goto("https://app.blackbox.ai/signup")

# Fill form
page.fill('input[type="email"]', email)
page.fill('input[type="password"]', password)

# Click CREATE ACCOUNT
page.click('button:has-text("CREATE ACCOUNT")')

# Wait for verify page
page.wait_for_selector('text=Verify your email')

Pitfalls

No API-only signup: The next-action header is session-bound and dynamically generated — HTTP-only signup is not feasible
Email domain blocking: Blackbox appears to filter/block t-online.de and Gmail alias addresses for verification emails
Google OAuth blocking: Google considers Blackbox's OAuth integration "unsafe" and blocks sign-in via CDP
Verification is hard requirement: Unverified accounts cannot login (500 error on /api/auth/callback/credentials)
CSRF token: Available at /api/auth/csrf but login requires verification first

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