---
title: Consumption
summary: How a consuming application references, constructs, calls, and disposes the proxy.
status: draft
owner: SAIF.Core documentation
last_reviewed: 2026-09-24
---

# Consumption

A consumer obtains fax delivery by constructing `FaxServiceProxy` per call from `SAIF.Services.WCF.Services.FaxService`, which is in turn part of `SAIF.Services.Web.Proxies` and documented as a consuming library at [`SAIF.Services.Web.Proxies` overview](../../libraries/saif-services-web-proxies/overview.md).

## Reference style

| Field | Value |
| --- | --- |
| Mechanism | Service Reference (svcutil) |
| Declared in | `Services/SAIF.Services.Web.Proxies/Service References/Fax/Reference.svcmap` |
| Generated artifacts | `Services/SAIF.Services.Web.Proxies/Service References/Fax/Reference.cs` |
| Target framework | .NET Framework 4.6.2 |
| Regeneration command | Visual Studio "Update Service Reference" |

## Construction

```csharp
public FaxServiceProxy(string serviceUrl)
{
    Enforce.ArgumentNotNullOrWhiteSpace(serviceUrl, nameof(serviceUrl));
    var binding = new BasicHttpBinding(BasicHttpSecurityMode.TransportCredentialOnly)
    {
        MaxReceivedMessageSize = int.MaxValue,
        MaxBufferSize = int.MaxValue,
        ReaderQuotas = { MaxArrayLength = int.MaxValue }
    };
    binding.Security.Transport.ClientCredentialType = HttpClientCredentialType.Windows;
    webService = new FaxServiceSoapClient(binding, new EndpointAddress(serviceUrl));
}
```

| Step | Requirement |
| --- | --- |
| Endpoint address | Constructor argument, resolved by `FaxService` from `WcfEnvironmentService.GetConfigSetting(EnvironmentConfigKeys.FaxSoapServiceUrl)` |
| Binding | Constructed in code — `BasicHttpBinding(TransportCredentialOnly)` with Windows client credentials |
| Credentials | Ambient Windows identity of the process, or the impersonated identity if the WCF host impersonates* |
| Initialization | Single-constructor |

## Endpoint configuration

| Setting | Value | Source | Changeable without a rebuild |
| --- | --- | --- | --- |
| Endpoint address | `http://websvcprod/webservices/SAIFFaxService/faxservice.asmx` | `Services/SAIF.Services.WebApi/EnvironmentApi/App_Data/environments.xml:16,35,54,73,91,109` | Yes |
| Binding configuration | Constructed in code | `Services/SAIF.Services.Web.Proxies/FaxServiceProxy.cs:18-28` | No |
| Security mode | `TransportCredentialOnly` | `FaxServiceProxy.cs:18` | No |

The `app.config` `<client><endpoint name="FaxServiceSoap">` entry (`Services/SAIF.Services.Web.Proxies/app.config:60`, address `api.saif.com`) is present but is not used at runtime, because the wrapper supplies an explicit `Binding` and `EndpointAddress` to the generated constructor.

## Resilience

| Concern | Finding | Configurable by consumer | Source | Tech debt |
| --- | --- | --- | --- | --- |
| Timeout | None configured — binding defaults apply | No | `FaxServiceProxy.cs:18-28` | Yes |
| Retry | None configured | No | — | Yes |
| Circuit breaking | None configured | No | — | Yes |
| Thread safety | Not determined from source | — | — | No |
| Cancellation | Not supported — no cancellation on any call site | — | `FaxServiceProxy.cs:43` | Yes |
| Message size limits | `MaxReceivedMessageSize`/`MaxBufferSize`/`MaxArrayLength` all set to `int.MaxValue` | Yes | `FaxServiceProxy.cs:20-22` | Yes |

The unbounded quotas are copied boilerplate rather than a deliberate choice — the response is empty, so the practical exposure is small, but the setting removes a real safeguard against an oversized response — see [Tech debt](tech-debt.md).

## Disposal

| Aspect | Finding |
| --- | --- |
| Disposal performed | `Close()` |
| Faulted channel handled | No — a faulted channel throws from disposal and masks the original failure* |
| Wrapper responsibility | `FaxServiceProxy` disposes the generated proxy; `FaxService.Dispose()` disposes the wrapper |
| Source | `Services/SAIF.Services.Web.Proxies/FaxServiceProxy.cs:57-65`; `Services/SAIF.Services.WCF/Services/FaxService.cs:59-67` |

```csharp
public void Dispose()
{
    webService.Close();
}
```

## Error handling for consumers

| Failure | Surfaces as | Consumer action |
| --- | --- | --- |
| Service unreachable | `EndpointNotFoundException`† | None — propagates through `FaxService.SendFax` to WCF |
| SOAP fault returned | `FaultException`† | None — propagates unchanged |
| Timeout exceeded | `TimeoutException`† | None — propagates unchanged |
| Response larger than the message size limit | Not applicable — the response is empty | — |
| Empty or absent output message | Not applicable — `Send` is one-way | — |

With multiple recipients, a mid-loop failure at `FaxService.SendFax` leaves earlier recipients faxed and later ones not, and the caller receives no indication of which; the temp file write to `fullFilePath` is also not cleaned up when a `Send` call throws, because the delete happens only after the loop completes.

## Usage examples

```csharp
// Send a fax to each recipient in the request, using a temp copy of the document
foreach (var recipient in config.Recipients)
{
    proxy.SendFax(recipient, fullFilePath);
}
```

| Scenario | Operations used | Notes |
| --- | --- | --- |
| Send one document to multiple fax recipients | `Send` | Called once per recipient from `FaxService.SendFax` |

## Lifecycle guidance

| Question | Answer |
| --- | --- |
| Construct once or per call | Per service instance* — constructed from `OperationContext.Current` in the `FaxService` constructor |
| Disposable | Yes (`IDisposable`) |
| Safe to share across threads | Not determined from source |

## Related documentation
- [Client index](index.md)
- [Overview](overview.md)
- [Architecture](architecture.md)
- [Contract](contract.md)
- [Operation map](operation-map.md)
- [Client reference](reference.md)
- [Dependencies](dependencies.md)
- [Tech debt](tech-debt.md)

> **Note:** Statements marked with `†` are derived from dependency library
> documentation via the Legends CLI. Statements marked with `*` were inferred
> from code structure or contextual evidence.

## Sources
- `Services/SAIF.Services.Web.Proxies/FaxServiceProxy.cs`
- `Services/SAIF.Services.WCF/Services/FaxService.cs`
- `Services/SAIF.Services.Web.Proxies/app.config`