# Real-time Pricing

MechCloud displays cost information directly in the plan output before any infrastructure changes are applied. This enables cost-aware infrastructure decisions during development rather than discovering costs after deployment.

### Overview

When generating an execution plan, MechCloud calculates and displays comprehensive cost information for GCP resources that have associated costs.

### Supported Billing Models

| Model                | How it appears in the plan                  | Examples                       |
| -------------------- | ------------------------------------------- | ------------------------------ |
| Usage-based (hourly) | Hourly rate + max monthly total (730 hours) | Compute Engine VM, GKE Cluster |
| Storage (GB-month)   | Rate + total when size is known             | Persistent Disk                |

#### Usage-Based Charges (Price + Cost)

For resources with **predictable usage patterns**, MechCloud shows both price rates and calculated costs:

* Compute Engine instance hours
* Persistent Disk storage (GB-Mo)
* GKE Cluster management fee

Example: A Compute Engine `e2-micro` instance shows `price: $0.00835/Hrs, monthly: $6.10`

### Cost Change Tracking

MechCloud displays cost change percentages for all resource actions, helping you understand the financial impact of infrastructure changes.

#### Create Actions

When creating new resources, the cost change is **+100%** (from $0 to the new cost):

```
vm1 (action: create, price: $0.00835/Hrs, monthly: $6.10, change: +100%)
```

#### Update Actions

When modifying existing resources, the change percentage reflects the actual cost difference.

#### Delete Actions

When deleting resources, the cost change is **-100%** (from current cost to $0):

```
vm1 (action: delete, price: $0.00/Hrs, monthly: $0.00, change: -100%)
```

### Plan Output Examples

#### Compute Engine Instance (Usage-Based Charges)

Compute Engine instances have predictable usage patterns, so MechCloud calculates and displays actual hourly and monthly costs.

**Creating a Compute Engine instance:**

```yaml
defaults:
  zone: us-central1-a

resources:
  - type: compute.v1.instance
    name: vm1
    props:
      machine_type: machineTypes/e2-micro
      disks:
        - boot: true
          auto_delete: true
          initialize_params:
            disk_size_gb: 30
            disk_type: diskTypes/pd-standard
            source_image: projects/ubuntu-os-cloud/global/images/family/ubuntu-2404-lts
      network_interfaces:
        - subnetwork: subnetworks/subnet1
          access_configs:
            - type: ONE_TO_ONE_NAT
              name: External NAT
```

**Plan output:**

```
vm1 (action: create)
=> Price (vCPU) - price: $0.02289/Hrs, quantity: 2, monthly: $33.42, change: +100%
=> Price (RAM) - price: $0.00308/GB-Hrs, quantity: 1, monthly: $2.25, change: +100%
=> Price (Boot Disk) - price: $0.04/GB-Mo, quantity: 30, monthly: $1.20, change: +100%
```

The plan shows:

* **vCPU price**: Calculated hourly cost for vCPUs.
* **RAM price**: Calculated hourly cost for Memory (GB).
* **Boot Disk**: Calculated monthly cost for the specified Persistent Disk.
* **Monthly**: Estimated monthly cost (hourly × 730 hours).
* **Change**: `+100%` - new resource.

### Supported Resources

MechCloud provides real-time pricing for the following GCP resource types:

| Offering        | Resource Type                              |
| --------------- | ------------------------------------------ |
| Compute Engine  | Instance (VM)                              |
|                 | Disk (Persistent Disk)                     |
|                 | Address (Static External IP)               |
|                 | Forwarding Rule (Load Balancer)            |
| GKE             | Cluster                                    |
|                 | Node Pool                                  |
| Cloud SQL       | Instance (MySQL / PostgreSQL / SQL Server) |
| Memorystore     | Redis Instance                             |
| Cloud Storage   | Bucket                                     |
| Cloud DNS       | Managed Zone                               |
| Cloud Run       | Service                                    |
| Cloud Functions | Function                                   |
| Pub/Sub         | Topic                                      |
| Cloud Spanner   | Instance                                   |
| Cloud NAT       | Gateway (Router)                           |
| VPN             | Tunnel                                     |

For detailed pricing examples, see [Examples (Resources With Cost)](https://docs.mechcloud.io/cloud-computing/stateless-iac/gcp/examples-resources-with-cost).

### Regional Pricing

Costs vary by GCP region. MechCloud automatically applies region-specific pricing.

### Using Pricing Data

#### Track Environment Costs

When generating plans for different Resource Contexts:

```
Development environment (context: app-dev)
Monthly cost: $125.43

Production environment (context: app-prod)
Monthly cost: $892.15
```

### Best Practices

**Include cost justification in code comments** - Document why specific instance types or sizes were chosen.

**Compare costs during code review** - Review cost deltas alongside configuration changes.

**Track cost trends over time** - Save plan outputs to monitor infrastructure cost evolution.

**Use Resource Context for cost isolation** - Separate cost tracking by environment (dev, staging, prod).

**Monitor actual vs estimated costs** - Compare MechCloud estimates against actual cloud bills to refine understanding.

### Integration with Stateless IaC

Real-time pricing works seamlessly with MechCloud's stateless architecture:

**Fresh pricing every plan** - No stale data from state files

**Accurate cost deltas** - Costs compared against actual current state

**Environment isolation** - Resource Context enables per-environment cost tracking

### Next Steps

* [Examples (Resources With Cost)](https://docs.mechcloud.io/cloud-computing/stateless-iac/gcp/examples-resources-with-cost)
* [Authoring Desired State](https://docs.mechcloud.io/cloud-computing/stateless-iac/gcp/authoring-desired-state)