> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mrdn.finance/llms.txt
> Use this file to discover all available pages before exploring further.

# Suppliers

> Who serves the models behind the router, how routing works, and what a request costs

A **supplier** is an upstream network that actually serves inference. Meridian
routes to them, prices from their catalogs, and settles their payment
challenges. Suppliers are registry entries, not hardcoded clients. The catalog
tells you which ones are live, what they charge, and how they expect to be paid.

<div className="mrdn-providers">
  <a className="mrdn-provider mrdn-provider--emerald" href="https://chat.dphn.ai" target="_blank" rel="noopener noreferrer">
    <header className="mrdn-provider__head">
      <h3>Dolphin</h3>
      <span className="mrdn-provider__status">Free</span>
    </header>

    <figure className="mrdn-provider__art">
      <img src="https://mintcdn.com/meridian-11ea0994/UDEgPsLdERbrDhOM/images/dolphin-logo.png?fit=max&auto=format&n=UDEgPsLdERbrDhOM&q=85&s=b06512669823251d3c8562131935d5fe" alt="" width="180" height="180" data-path="images/dolphin-logo.png" />
    </figure>

    <p className="mrdn-provider__meta">payment: none</p>
    <span className="mrdn-provider__link">chat.dphn.ai →</span>
  </a>

  <a className="mrdn-provider mrdn-provider--blue" href="https://www.surplusintelligence.ai" target="_blank" rel="noopener noreferrer">
    <header className="mrdn-provider__head">
      <h3>Surplus</h3>
      <span className="mrdn-provider__status">topup balance</span>
    </header>

    <figure className="mrdn-provider__art">
      <img src="https://mintcdn.com/meridian-11ea0994/UDEgPsLdERbrDhOM/images/surplus-logo.png?fit=max&auto=format&n=UDEgPsLdERbrDhOM&q=85&s=f039390a7a3d6c77580134961d3b3ed6" alt="" width="809" height="809" data-path="images/surplus-logo.png" />
    </figure>

    <p className="mrdn-provider__meta">payment: x402</p>
    <span className="mrdn-provider__link">surplusintelligence.ai →</span>
  </a>

  <a className="mrdn-provider mrdn-provider--split" href="https://network.antseed.com" target="_blank" rel="noopener noreferrer">
    <header className="mrdn-provider__head">
      <h3>AntSeed</h3>
      <span className="mrdn-provider__status">topup balance</span>
    </header>

    <figure className="mrdn-provider__art">
      <img src="https://mintcdn.com/meridian-11ea0994/UDEgPsLdERbrDhOM/images/antseed-logo.svg?fit=max&auto=format&n=UDEgPsLdERbrDhOM&q=85&s=309b523c5251e9826b16cc0e9b9e61a0" alt="" width="80" height="80" data-path="images/antseed-logo.svg" />
    </figure>

    <p className="mrdn-provider__meta">payment: x402</p>
    <span className="mrdn-provider__link">network.antseed.com →</span>
  </a>
</div>

## The registry

`GET /v1/inference/providers` returns each supplier with its capabilities,
settlement details, and top-up metadata. Treat it as the source of truth rather
than shipping constants in your client.

| Supplier | Site                                                         | Payment kind       | Chat        | Top-up | Templates | Balance                        |
| -------- | ------------------------------------------------------------ | ------------------ | ----------- | ------ | --------- | ------------------------------ |
| Dolphin  | [chat.dphn.ai](https://chat.dphn.ai)                         | `none`             | Live        | -      | Yes       | -                              |
| Surplus  | [surplusintelligence.ai](https://www.surplusintelligence.ai) | `prepaid` + `x402` | Flagged     | Yes    | No        | USDC on Base at your buyer key |
| AntSeed  | [network.antseed.com](https://network.antseed.com)           | `prepaid`          | Coming soon | Yes    | No        | Merchant contract balance      |

Payment kinds are additive and clients should skip values they do not recognise:

* `none`: call immediately. Dolphin is the current free supplier.
* `x402`: call once for a validated `402` offer, sign it, retry with
  `PAYMENT-SIGNATURE`.
* `prepaid`: fund the supplier balance using its registry `topup` block.

## Namespaced model ids

Every model is addressed as `supplier/upstream-model-id`:

```text theme={"system"}
dolphinserver:24B              # unprefixed ids stay Dolphin, for compatibility
surplus/zai-org/glm-4.5
```

That naming is the whole portability story. When a supplier is added, removed, or
reprices, the catalog changes and your request shape does not.

## Dolphin

The free tier at [chat.dphn.ai](https://chat.dphn.ai). Chat runs without a
wallet and without a payment challenge, and it is the only supplier that exposes
**templates**: named styles such as `logical` (the default) or creative
variants, fetched from `/v1/inference/templates`. Sending a template to any
other supplier is rejected.

## Surplus

The first paid supplier and an OpenAI-compatible marketplace at
[surplusintelligence.ai](https://www.surplusintelligence.ai). Hundreds of
models, each carrying its own per-token input and output price in the catalog.

Meridian does not choose a seller. Surplus routes each request to its cheapest
healthy seller internally, so you get marketplace pricing without running the
matching yourself.

Settlement is USDC on Base. Your prepaid balance is literally the USDC balance of
your derived buyer key, so it is verifiable onchain and withdrawable at any time.

### Cost of a request

| Component            | Source                               | Paid to |
| -------------------- | ------------------------------------ | ------- |
| Per-token price      | Surplus catalog, shown in the picker | Surplus |
| Per-request x402 fee | Flat, currently \$0.003              | Surplus |
| Meridian margin      | None on chat                         | -       |

You sign Surplus's own x402 challenge and Surplus is the only payee. Meridian
takes no margin on chat. The app caps any single paid message so a malformed
challenge cannot drain a balance, and the facilitator validates every challenge
server-side before relaying it.

### Failure behaviour

If Surplus is unavailable, paid chat is unavailable; free Dolphin chat is
unaffected. There is no automatic cross-supplier failover today because pricing
and model identity differ per supplier, so switching is a catalog choice you make,
not a silent substitution.

## AntSeed

A peer-to-peer inference network at [network.antseed.com](https://network.antseed.com)
where independent sellers run nodes. Its catalog is live peer data: models
appear while sellers are online, priced from the cheapest available peer.

Funding works today: the [top-up gateway](/inference/topup-gateway) credits an
`AntseedDeposits` balance on Base, and the balance shows in the finance panel.
Chat is deferred until the per-request node bridge ships, so AntSeed models
render in the marketplace as **coming soon**.

<Note>
  Availability, pricing, modality, and payment mechanics are registry data.
  Always read the current `/v1/inference/models` and `/v1/inference/providers`
  responses instead of caching them as client constants.
</Note>

<Columns cols={2}>
  <Card title="Inference API" icon="terminal" href="/api-reference/inference/overview">
    Endpoint reference for the catalog and chat surfaces.
  </Card>

  <Card title="Funding" icon="wallet" href="/inference/topup-gateway">
    How prepaid supplier balances get credited.
  </Card>
</Columns>