Hard spending limits that actually enforce. Intelligence that tells you exactly where tokens are wasted and what to do about it.
Deploys on your infrastructure. Your data never leaves.
Agentic workflows use 5–30x more tokens per task. A single runaway loop burns hundreds in minutes with no automatic shutoff.
Budget controls from existing tools need enterprise contracts. Series A–C teams get dashboards and alerts — not enforcement.
You know your total bill. You don't know which feature, end-user, or team caused it. Unit economics are a guess.
Monitoring shows the damage. Nobody tells you your RAG pipeline retrieves 8 chunks when 3 would do, or that half your calls should use a cheaper model.
Swap your base URL. Optionally add intelligence headers. Your existing SDK calls work unchanged.
from openai import OpenAI client = OpenAI( api_key="sk-your-key", # default: api.openai.com ) response = client.chat.completions.create( model="gpt-4o", messages=messages, )
from openai import OpenAI client = OpenAI( api_key="tw_live_your_key", base_url="https://proxy.costline.dev/v1", default_headers={ "X-TW-Feature": "checkout", "X-TW-Customer": customer_id, } ) response = client.chat.completions.create( model="gpt-4o", messages=messages, )
Hard stops keep you safe. Intelligence makes you efficient. Both run on your infrastructure.
Per-org, per-feature, per-customer, per-team. When the limit hits, traffic stops. Not a soft alert — a guarantee. Sub-10ms overhead.
Decompose your LLM bill by product feature, end-user account, and internal team. See the true cost of serving each user for unit economics.
Identifies when your pipeline retrieves more context than is useful. Recommends specific k and score threshold changes with estimated savings.
Detects when expensive models handle simple tasks. Surfaces specific opportunities to route to cheaper models without quality loss.
Every recommendation is specific, quantified, and actionable. Not "use fewer tokens" — exactly what to change and how much you'll save.
CostLine deploys on-prem or in your cloud via Helm, Docker Compose, or Terraform. Zero customer data ever leaves.
Deploy on your infrastructure. Pay once a year. Scale without surprise bills.
Early adopter pricing — locked in for your first year.
Small engineering teams
Growth-stage AI companies
Custom requirements
15-minute conversation. We'll show you what CostLine would find in your current LLM spend.