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

# mpp_fetch — Fetch an MPP-Gated URL via Active Session

> Commit an off-chain micropayment and fetch an MPP-gated URL in one call. Requires an active session opened with mpp_open_session. No on-chain tx per call.

`mpp_fetch` fetches an MPP-gated URL by committing a payment against your active payment channel. Unlike `x402_fetch`, this does not broadcast a Stellar transaction on every call — instead, the Hub advances the channel state off-chain. All committed amounts are settled in a single on-chain transaction when you call `mpp_close_session`.

This makes `mpp_fetch` ideal for high-frequency, low-cost API calls where submitting a Stellar transaction per request would be impractical.

## Prerequisites

You must have an active MPP session before calling `mpp_fetch`. Open one with `mpp_open_session`. If no session is open when you call `mpp_fetch`, the tool returns an error immediately without making any network request.

## Parameters

<ParamField path="url" type="string" required>
  The MPP-gated URL to fetch. Must be a valid HTTP or HTTPS URL. The server at this URL must support the MPP payment protocol and accept channel payment proofs from the Hub.
</ParamField>

## Response

### Success

```json title="Success response" theme={null}
{
  "status": "ok",
  "data": {
    "response_body": "<content returned by the server>",
    "amount_committed_usdc": 0.001,
    "channel_remaining_usdc": 0.987,
    "channel_id": "ch_4f8a2b1e"
  }
}
```

<ResponseField name="status" type="string">
  Always `"ok"` on success.
</ResponseField>

<ResponseField name="data.response_body" type="string">
  The response body returned by the MPP-gated server.
</ResponseField>

<ResponseField name="data.amount_committed_usdc" type="number">
  The USDC amount committed to the channel for this specific call.
</ResponseField>

<ResponseField name="data.channel_remaining_usdc" type="number">
  How much USDC remains in the channel budget after this commitment.
</ResponseField>

<ResponseField name="data.channel_id" type="string">
  The ID of the active channel used for this request.
</ResponseField>

### Error — no active session

```json title="No active session" theme={null}
{
  "status": "error",
  "reason": "No active MPP session. Call mpp_open_session first."
}
```

### Error — budget exhausted

```json title="Budget exhausted" theme={null}
{
  "status": "error",
  "reason": "Channel budget exhausted: 0.00 USDC remaining"
}
```

## Example

```json title="Tool call" theme={null}
{
  "tool": "mpp_fetch",
  "input": {
    "url": "https://api.example.com/stream/tick"
  }
}
```

```json title="Response" theme={null}
{
  "status": "ok",
  "data": {
    "response_body": "{\"price\": 0.9821, \"asset\": \"XLM/USDC\"}",
    "amount_committed_usdc": 0.001,
    "channel_remaining_usdc": 0.987,
    "channel_id": "ch_4f8a2b1e"
  }
}
```

<Tip>
  Use the `demo_url` returned by `mpp_open_session` to test `mpp_fetch` without a live merchant server. Call `mpp_status` periodically to confirm your remaining budget before making a large batch of requests.
</Tip>