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

# Serverless Metrics API

> Query per-account Serverless performance metrics for pass.wafer.ai.

Get per-account Serverless SLA metrics for traffic served through `pass.wafer.ai`. The response includes summary latency, TTFT, tokens-per-second, token counts, error counts, and a time series over the requested lookback window.

Serverless metrics are scoped to the account that owns the Serverless API key. They do not expose fleet-wide backend identities, live backend gauges, or other customers' traffic.

## Run

```bash theme={null}
curl -s "https://api.wafer.ai/v1/endpoints/metrics?endpoint=pass.wafer.ai&range_minutes=60&model=<MODEL_ID>" \
  -H "Authorization: Bearer <SERVERLESS_API_KEY>"
```

## Parameters

* `endpoint` (required): `pass.wafer.ai`
* `range_minutes` (optional): `5`, `15`, `30`, `60`, `360`, `1440`, `10080`, `43200`
* `model` (optional): filter to one resolved model, such as `Qwen/Qwen3-Coder-480B-A35B-Instruct-FP8`
* default `range_minutes`: `60`

## Response Shape

```json theme={null}
{
  "endpoint": "pass.wafer.ai",
  "range_minutes": 60,
  "queried_at": "2026-05-22T19:55:19+00:00",
  "summary": {
    "total_requests": 42,
    "rps": 0.01,
    "ttft_p50_ms": 410.0,
    "ttft_p90_ms": 1250.0,
    "ttft_p95_ms": 2100.0,
    "ttft_p99_ms": 3200.0,
    "tps_p10": 52.0,
    "tps_p50": 92.0,
    "tps_p90": 155.0,
    "tps_p99": 180.0,
    "latency_p50_ms": 2100.0,
    "latency_p90_ms": 6400.0,
    "latency_p99_ms": 12000.0,
    "cache_hit_pct": 72.5,
    "total_input_tokens": 480000,
    "total_output_tokens": 42000,
    "total_cache_read_tokens": 348000,
    "count_2xx": 41,
    "count_4xx": 1,
    "count_5xx": 0,
    "error_rate_pct": 2.4,
    "concurrent_requests": 2,
    "active_accounts": null,
    "engine_running_requests": null,
    "engine_queue_depth": null,
    "engine_kv_cache_hit_rate_pct": null,
    "engine_kv_cache_usage_pct": null,
    "engine_preemptions_in_range": null
  },
  "backends": [],
  "timeseries": [
    {
      "time": "2026-05-22T18:55:00Z",
      "requests": 12,
      "tps_p10": 50.0,
      "tps_p50": 92.0,
      "tps_p90": 150.0,
      "tps_p99": 175.0,
      "ttft_p50_ms": 410.0,
      "ttft_p90_ms": 1200.0,
      "ttft_p95_ms": 1850.0,
      "ttft_p99_ms": 3000.0,
      "latency_p50_ms": 2100.0,
      "latency_p90_ms": 6400.0,
      "latency_p99_ms": 12000.0,
      "input_tokens": 48000,
      "cache_read_tokens": 34800,
      "error_count": 1
    }
  ]
}
```

## Key Fields

* `rps`: average requests per second across the full window
* `ttft_p50_ms`, `ttft_p90_ms`, `ttft_p95_ms`, `ttft_p99_ms`: streaming time-to-first-token percentiles (`null` on non-streaming windows)
* `tps_p10`, `tps_p50`, `tps_p90`, `tps_p99`: output tokens-per-second percentiles
* `latency_p50_ms`, `latency_p90_ms`, `latency_p99_ms`: end-to-end latency percentiles
* `cache_hit_pct`: cache-read prompt tokens divided by total input tokens
* `count_2xx`, `count_4xx`, `count_5xx`: request count by status class
* `error_rate_pct`: `4xx + 5xx` divided by total requests
* `concurrent_requests`: recent activity count for the scoped account
* `timeseries[*]`: per-bucket `requests`, the full TPS / TTFT / latency percentile set, plus `input_tokens`, `cache_read_tokens`, and `error_count`. The two token sums let you render a "cached vs total input" overlay without a second query. Bin size is derived from `range_minutes`.

## Serverless Scoping

* Only Serverless API keys can query `endpoint=pass.wafer.ai`.
* Results are scoped to the owning Serverless account for the bearer key.
* `model` filters the resolved model that served the request.
* `backends` is empty for Serverless because backend identities are fleet-level data.
* Engine gauge fields and `active_accounts` are `null` for Serverless because they are fleet-level metrics.

## Timeseries Bin Sizes

The `timeseries` bin width is derived from `range_minutes`:

| `range_minutes` | Bin size   |
| --------------- | ---------- |
| `5`, `15`       | 1 minute   |
| `30`            | 2 minutes  |
| `60`            | 5 minutes  |
| `360` (6h)      | 15 minutes |
| `1440` (24h)    | 30 minutes |
| `10080` (7d)    | 3 hours    |
| `43200` (30d)   | 12 hours   |

## Errors

* `401`: missing or invalid API key
* `403`: the API key is not a Serverless key for `pass.wafer.ai`
* `422`: invalid `range_minutes`, `endpoint`, or `model`
* `502`: upstream metrics query failed