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

# Measure Boost traffic

> Use Boost response headers and CLI metrics to measure cache hits, forwarded requests, latency, and avoided upstream calls.

Every Boost response identifies who answered, how long Boost spent on the request, and how many request items were served without reaching your provider.

## Response headers

| Header               | Values                        | Meaning                                                                                                  |
| -------------------- | ----------------------------- | -------------------------------------------------------------------------------------------------------- |
| `x-cache`            | `HIT`, `MISS`                 | `HIT` when Boost served the single call or every item in a batch; otherwise `MISS`                       |
| `x-edge-source`      | `cache`, `static`, `endpoint` | The system that produced the response                                                                    |
| `x-edge-billable`    | Integer                       | Number of request items Boost served: `1` or `0` for a single call, or the served-item count for a batch |
| `x-edge-duration-ms` | Integer                       | Wall-clock time Boost spent serving the request                                                          |
| `x-edge-version`     | Build string                  | Boost build that handled the request                                                                     |
| `x-edge-region`      | AWS region                    | Edge region that handled the request, such as `us-west-2`                                                |

The `x-edge-billable` name predates Boost's free pricing. Treat it as a served-item count, not a monetary charge.

## Single requests

For a single JSON-RPC request:

* `x-cache: HIT` and `x-edge-billable: 1` mean Boost served the call without sending it upstream.
* `x-cache: MISS` and `x-edge-billable: 0` mean the configured endpoint answered.
* `x-edge-source: static` identifies methods answered directly by the Boost edge, such as `eth_chainId`.

## Batch requests

Read `x-edge-billable` instead of relying on `x-cache` alone. `x-cache` is `HIT` only if Boost served every item.

For a batch of 45 calls where Boost serves 44:

```text theme={"dark"}
x-cache: MISS
x-edge-billable: 44
```

The batch contains one forwarded item, so the aggregate cache header is a miss even though most calls avoided the upstream.

## Calculate an avoided-upstream rate

Count JSON-RPC items, not HTTP requests:

```text theme={"dark"}
avoided upstream rate = sum(x-edge-billable) / total JSON-RPC items
```

This rate measures calls Boost served. To estimate monetary savings, apply your provider's pricing model to those avoided calls. Providers can price methods, compute units, or plans differently, so the headers do not represent an exact dollar amount.

## CLI metrics

Fetch aggregate endpoint metrics with:

```bash theme={"dark"}
goldsky boost metrics
```

The command reports cache hits, latency, miss reasons, and provider-level statistics. See the [`goldsky boost metrics` reference](/reference/cli#boost-metrics) for its current output and options.

## What to monitor

* **Served-item rate:** The share of JSON-RPC items with `x-edge-billable` greater than zero
* **Miss reasons:** Whether calls miss because of method eligibility, block tags, unavailable data, or batch size
* **Boost duration:** `x-edge-duration-ms`, split by response source
* **Upstream errors and latency:** Requests with `x-edge-source: endpoint`, grouped by provider

If an eligible method repeatedly misses, use the [troubleshooting guide](/boost/troubleshooting#eligible-requests-keep-missing).


## Related topics

- [Set up Boost](/boost/quickstart.md)
- [Cut RPC costs with Boost](/boost.md)
- [Configure Boost upstreams](/boost/configuration.md)
- [Boost reference](/boost/reference.md)
- [Troubleshoot Boost](/boost/troubleshooting.md)