> For the complete documentation index, see [llms.txt](https://docs.tolvyn.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tolvyn.io/getting-started/readme.md).

# What is TOLVYN?

TOLVYN is the financial control plane for AI infrastructure. Every AI API call — metered, attributed, governed.

***

## What you get

* **Real-time cost metering.** Every request that goes through TOLVYN is recorded with model, token counts, latency, and exact cost in microdollars. Pricing is live, not estimated.
* **Budget enforcement.** Set hard, soft, or approval budgets per team, service, agent, user, or end-customer. Hard budgets block requests at the proxy before the provider is called.
* **Tamper-evident audit ledger.** Every request appends to a SHA-256 hash-chained ledger with HMAC signatures. Verifiable at any time via `GET /v1/ledger/verify`. Designed for financial evidence, not just monitoring.
* **SDKs and a proxy.** Register your provider key with TOLVYN once, point your SDK's base URL at the proxy, and use a TOLVYN key in place of your provider key. The TOLVYN SDKs for Python, Node.js and Go wrap the official clients so the call sites stay as they are; any HTTP client works against `proxy.tolvyn.io` directly. OpenAI, Anthropic, Google and DeepSeek supported.

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## 60-second quickstart

1. Sign up at [app.tolvyn.io/signup](https://app.tolvyn.io/signup)
2. **Providers** (`/providers`) — add your OpenAI / Anthropic / Google / DeepSeek key (stored encrypted server-side)
3. **API Keys → Create** — copy the `tlv_live_...` key (shown once)
4. Use it:

   ```python
   from tolvyn import OpenAI
   client = OpenAI(tolvyn_api_key="tlv_live_...")
   client.chat.completions.create(model="gpt-4o-mini", messages=[...])
   ```
5. Open the dashboard — the request appears within seconds with cost, tokens, and latency.

Full walkthrough: [Quickstart](/getting-started/quickstart.md).

***

## Where to next

| If you want to...                             | Go to                                                                      |
| --------------------------------------------- | -------------------------------------------------------------------------- |
| Get to a working request in 5 minutes         | [Quickstart](/getting-started/quickstart.md)                               |
| Choose between SDK and proxy mode             | [Integration Modes](/getting-started/integration-modes.md)                 |
| See SDK reference for your language           | [Python](/sdks/python.md) · [Node.js](/sdks/nodejs.md) · [Go](/sdks/go.md) |
| Move from Helicone, Portkey, or direct OpenAI | [Migration guides](/migrate-to-tolvyn/index.md)                            |

***

## Need help?

Email <founder@tolvyn.io>.