Authentication

API Key Authentication

All requests to the 50c API must include your API key in the Authorization header:

curl -X POST https://api.50c.ai/tools/genius \
  -H "Authorization: Bearer cv_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"problem": "Your question"}'

Key Types

Prefix	Type	Description
cv_	Production	Main API key for production use
cv_sub_	Sub-key	Enterprise delegable keys with limits
cv_test_	Sandbox	Testing without charges
cv_agent_	Agent	Developer-registered agent keys
titan_vip_	VIP	Elite plan only

x402 Payment Authentication

For autonomous agents, use x402 payments instead of API keys:

# First call returns 402 with payment instructions
curl -X POST https://api.50c.ai/tools/genius \
  -H "Content-Type: application/json" \
  -d '{"problem": "Your question"}'

# Response includes payment headers:
# X-Payment-Required: true
# X-Payment-Amount: 50
# X-Payment-Currency: USDC
# X-Payment-Network: base

# Retry with payment token
curl -X POST https://api.50c.ai/tools/genius \
  -H "X-Payment: <signed_payment_token>" \
  -H "Content-Type: application/json" \
  -d '{"problem": "Your question"}'

See x402 Payments for details.

Cloudflare tools (cf_*)

For Cloudflare suite tools, the 50c API key authorizes the call; your Cloudflare permission is a separate token.

• Prefer header: X-Cloudflare-Token: <cloudflare_api_token>
• Alternatively, JSON body field: cloudflare_token (e.g. MCP tools/call when headers are not available)

50c does not persist Cloudflare tokens. Create tokens in the Cloudflare dashboard with least privilege for the zones you automate.

Errors

Status	Error	Solution
401	invalid_api_key	Check your key format
401	key_not_found	Key doesn’t exist or was revoked
402	insufficient_credits	Top up at 50c.ai/subscribe
403	rate_limited	Wait and retry