# `Daraja.C2B`
[🔗](https://github.com/okothkongo/daraja/blob/v0.1.1/lib/daraja/c2b.ex#L1)

Customer to Business (C2B) — receive payment notifications for Paybill or Till numbers.

## Register URLs

Register your confirmation and (optional) validation callback URLs:

    client = Daraja.Client.new()

    Daraja.C2B.register_url(client, %{
      short_code: "600984",
      response_type: "Completed",
      confirmation_url: "https://example.com/c2b/confirmation",
      validation_url: "https://example.com/c2b/validation"
    })

`response_type` controls what M-PESA does when your validation URL is unreachable:
- `"Completed"` — M-PESA completes the transaction automatically.
- `"Cancelled"` — M-PESA cancels the transaction automatically.

## Simulate (sandbox only)

Simulate a C2B payment in the sandbox environment:

    Daraja.C2B.simulate(client, %{
      short_code: "600984",
      command_id: "CustomerPayBillOnline",
      amount: 100,
      msisdn: "254708374149",
      bill_ref_number: "INV-001"
    })

## Handle Callbacks

Parse inbound validation and confirmation payloads posted by M-PESA to your registered URLs.
See `Daraja.C2B.Callback` for details.

# `result`

```elixir
@type result() ::
  {:ok, Daraja.C2B.Response.Success.t()}
  | {:error, :invalid_request, list()}
  | {:error, :auth_failed, Daraja.APIError.t()}
  | {:error, :http_error, Daraja.APIError.t() | term()}
  | {:error, :request_failed,
     Daraja.C2B.Response.Error.t() | Daraja.APIError.t()}
```

# `register_url`

```elixir
@spec register_url(Daraja.Client.t(), map() | Daraja.C2B.RegisterUrlRequest.t()) ::
  result()
```

Registers callback URLs for C2B payment notifications.

Required params: `short_code`, `response_type`, `confirmation_url`, `validation_url`.

`response_type` must be `"Completed"` or `"Cancelled"` (sentence case).

Note: In production this is a one-time registration. To change URLs, delete
them via the M-PESA Org portal and re-register.

# `simulate`

```elixir
@spec simulate(Daraja.Client.t(), map() | Daraja.C2B.SimulateRequest.t()) :: result()
```

Simulates a C2B payment transaction. Sandbox only — not supported in production.

Required params: `short_code`, `command_id`, `amount`, `msisdn`.
Optional params: `bill_ref_number`.

`command_id` must be `"CustomerPayBillOnline"` or `"CustomerBuyGoodsOnline"`.

---

*Consult [api-reference.md](api-reference.md) for complete listing*