Stop AI spend before it's charged.
Prove every call after.
TOLVYN sits in front of OpenAI, Anthropic, Google and DeepSeek as one control plane for every AI call. It caps every team, service, agent and key before the provider is called, attributes every rupee or dollar to who spent it, and keeps a signed record you can verify. Hosted in India. Nothing to run. Prompts never stored.
Open-source pricing database · MIT and Apache-2.0 SDKs

- 4 providers through one proxy: OpenAI, Anthropic, Google and DeepSeek
- about 5 ms added at the median, in our own benchmark
- 14 security researchers credited
- 10,000 requests free, no credit card
The problem
Your AI bill doubled last month. You don't know why.
Cost attribution is broken
The bill arrives as one number. Which team? Which feature? Which customer? Nobody can answer the CFO's question.
AI agents have no governance
Your AI SDR, support bot, and coding agent each generate thousands of requests daily. None of them appear on one ledger.
There's no proof of what happened
When auditors ask for AI usage records, you have provider invoices and Slack screenshots. That's not a financial record.
How it works
A proxy that turns every call it meters into a financial record
Register your provider key with TOLVYN once, point your SDK's base URL at the proxy, and swap your provider key for a TOLVYN key. No SDK refactor.
What makes TOLVYN different
Control, and the evidence for it



- 01
Tamper-Evident Ledger
Every AI request TOLVYN meters is hash-chained and HMAC-signed. Cryptographic proof, not logs. Your CFO or auditor can re-verify the hash chain themselves with the script shipped in every evidence package — the HMAC is keyed on a secret TOLVYN holds, so it detects tampering by anyone without that key.
- 02
Per-End-Customer Attribution
Track AI cost per your customer. Know your AI COGS per customer. The unit economics SaaS founders are missing.
- 03
Invoice Reconciliation
Upload your OpenAI / Anthropic / Google usage export. TOLVYN shows the gap: spend on your provider bill that did not go through TOLVYN.
- 04
Agent Governance
Per-agent budgets. Cost anomaly alerts — one call over 10× the recent average. Kill switch. Every AI agent on one ledger.
- 05
Savings Analyzer
Nightly analysis identifies migration opportunities. Switch to a cheaper model where your actual usage patterns fit.
- 06
Pricing Change Alerts
When OpenAI changes prices, customers using affected models get an alert projecting the monthly impact from their last 30 days of usage.
Honest limits
What TOLVYN doesn’t do yet
- Budgets per end customer. End customers are attributed and reported, but a budget can only be set on the organization, a team, a service, an agent or an API key.
- Limits per agent run or task. Budgets and quotas are per period; there is no per-run limit yet.
- Amazon Bedrock, Azure OpenAI and Vertex AI. The providers TOLVYN proxies natively are OpenAI, Anthropic, Google's Gemini API and DeepSeek.
- Single sign-on. There is no SAML or OIDC sign-in yet; you sign in with email and password.
- A SOC 2 report. There is none yet. What an auditor gets today is the evidence package and the ledger it verifies.
- Gemini's Files API upload and Gemini's OpenAI-compatible endpoint. Both are answered with a named 501. Upload files to Google directly and pass the file reference through TOLVYN.
- A fallback in proxy mode. If TOLVYN is unreachable, a base-URL integration fails. Fail-open lives in the SDKs and needs your own provider key.
- More than one region. TOLVYN is hosted in India only.
A base-URL change, or one import
Change how you connect. Everything else identical.
# Before
from openai import OpenAI
client = OpenAI(api_key="sk-...")
# After
from tolvyn import OpenAI
client = OpenAI(
tolvyn_api_key="tlv_live_...",
openai_api_key="sk-...", # REQUIRED for fail-open; no key, no fallback
team="engineering",
service="chatbot-api"
)
# Everything else identical// Before
import OpenAI from 'openai'
const client = new OpenAI({ apiKey: 'sk-...' })
// After
import { OpenAI } from 'tolvyn'
const client = new OpenAI({
tolvynApiKey: 'tlv_live_...',
openAIApiKey: 'sk-...', // REQUIRED for fail-open; no key, no fallback
team: 'engineering',
service: 'chatbot-api'
})# Before
curl https://api.openai.com/v1/chat/completions \
-H "Authorization: Bearer sk-..."
# After (change the URL, keep everything else)
curl https://proxy.tolvyn.io/v1/proxy/openai/v1/chat/completions \
-H "Authorization: Bearer tlv_live_..." \
-H "X-Tolvyn-Team: engineering" \
-H "X-Tolvyn-Service: chatbot-api"Sample ledger
Sample rows, not customer data.| Time | Service | Model | Tokens | Cost |
|---|---|---|---|---|
| 14:23:01 | eng/chatbot-api | gpt-4o | 1,247 | $0.0089 |
| 14:23:02 | eng/search-svc | claude-opus-4-6 | 2,104 | $0.0252 |
| 14:23:03 | support/bot | gpt-4o-mini | 456 | $0.0003 |
| 14:23:05 | mktg/content | gpt-4o | 3,847 | $0.0312 |
| 14:23:07 | eng/chatbot-api | gpt-4o | 892 | $0.0071 |
| 14:23:09 | data/pipeline | claude-haiku-4-5 | 12,450 | $0.0094 |
| Total | 6 calls | 20,996 | $0.0821 |
pip install tolvyn · npm install tolvyn · go get github.com/tolvyn/tolvyn-go
Works with OpenAI, Anthropic, Google, and DeepSeek. If TOLVYN is unreachable, SDK mode automatically retries against the provider directly.
Already using another tool? Migration takes minutes.
Header-compatible. We read your existing helicone-property-* headers automatically.
Privacy floor: three organisations minimum
TOLVYN AI Cost Index
Anonymized cost benchmarks aggregated from real production AI traffic. A figure is published only when at least three organisations contribute to it, so the index shows what clears that floor — and nothing else.
Work with us
We work closely with a few early teams. Write to younus@tolvyn.io.
Start now
Start free. 10,000 requests. No credit card.
Point your base URL at TOLVYN, swap in a TOLVYN key. Cryptographic proof from request one.
Or book a 15-minute demo cal.com/tolvyn