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

# Cost & latency

> Per-step cost and time — spot where the money and milliseconds go.

Every Trace has a **cost & latency** rollup at the top, and per-step breakdowns beside every timeline entry.

## The rollup

At the top of every Trace:

* **Total cost** — dollar amount, plus token counts by model.
* **Total latency** — wall clock start to answer sent.
* **Compute** — sum of all model + tool time (excludes waiting).
* **Wait** — time spent waiting on external services (APIs, databases, humans in approval queues).

Wall clock = compute + wait + small overhead.

## Per-step breakdown

Each step in the timeline shows its individual cost and duration. Sorted view: click the cost column header to see the most expensive steps first.

Common offenders when cost is high:

* **Long prompts** — retrieval returning too many chunks. Reduce top-K in the preset.
* **Expensive model** — using a top-tier model when a mid-tier would do. Consider a fallback or a router.
* **Repeated tool calls** — Agent looping on the same tool. Fix the tool description or the Agent's role.
* **Enrichment on the fly** — should be pre-computed via a Foundry pipeline, not per-run.

## Latency waterfall

The waterfall view (click **Timing** in the top bar) shows latency as parallel bars. Anything not on the critical path can safely be optimized last.

Compute-bound steps show as solid bars; wait-bound show as hatched. Wait bars in the middle of the run usually mean serial API calls that could be parallelized in the Agent's tool config.

## Comparing runs

Click **Compare with...** on any Trace and pick another Trace (same Flow, different run). Side-by-side latency and cost view. Useful when:

* Latency spiked and you want to know which step changed.
* A new version increased costs — see where.
* A/B testing two Agents.

## Cost alerts

Per-Flow cost alerts fire when:

* A single run exceeds a threshold (e.g., "any run over \$1").
* Rolling average cost per run exceeds a threshold over N runs.
* Total daily/weekly/monthly spend exceeds a budget.

Configure in Flow settings → **Alerts**. Route to Slack, email, or a webhook.

## Cost per user / per tenant

If your runs carry scope keys, the **Insights** page can group cost by scope:

* Cost by user\_id — who costs the most.
* Cost by tenant — which customer is expensive.
* Cost by feature (via tags on Traces).

Great for pricing decisions, cost attribution, or spotting a runaway integration.

## Latency budgets

Set a **latency budget** per Flow. Runs exceeding the budget are flagged in the runs list. Common budgets:

* Chat: 3 seconds.
* Background: 30 seconds.
* Batch: 5 minutes.

Runs over budget aren't stopped — you're notified and can decide.

## Where the money actually goes

Model calls: usually 60-80% of cost. Embeddings and small helper models: 10-25%. Third-party tools with paid APIs: variable. Storage: negligible for most workloads.

If you're surprised where cost lives, the per-step view is where to look.