Rename customer-facing name from CYOT to External Phone Provider

CYOT remains the internal code name and is unchanged in wire-level identifiers (type names, CYOT_JWE_PRIVATE_KEY_PEM, SAS User-Agent); CONTRACT.md now notes this explicitly.

Author: Hou Chi Chan

README.md

@@ -1,4 +1,4 @@
-# CYOT Azure Function Sample
+# External Phone Provider — Azure Function Sample
 
 A provider-agnostic **OTP-delivery Azure Function** sample, implemented across multiple languages.
 Each language folder is a self-contained implementation of the **same design and the same

docs/CONTRACT.md

@@ -1,8 +1,12 @@
-# CYOT Function — Language-Agnostic Contract
+# External Phone Provider Function — Language-Agnostic Contract
 
 This is the **source of truth** every language implementation (`javascript/`, `dotnet/`, `python/`)
 must conform to. If an implementation disagrees with this document, the implementation is wrong.
 
+> **Naming.** "CYOT" (Choose Your Own Telecom) is the internal code name for this feature. It still
+> appears in wire-level identifiers that must not change — type names (`SendCyotOtpRequest`,
+> `CyotDeliveryContext`), the `CYOT_JWE_PRIVATE_KEY_PEM` app setting, and the caller's `User-Agent`.
+
 The design is intentionally simple: **one dispatch engine + drop-in provider adapters**. Adding a
 provider is adding one adapter file; adding a language is re-implementing this contract.
 

docs/ONBOARDING.md

@@ -1,9 +1,9 @@
 # Customer Onboarding
 
-A high-level guide to setting up, securing, and deploying the CYOT OTP Function. The steps are the same
-for every language (`javascript/`, `dotnet/`, `python/`); only the build/run commands differ (see each
-language's README). All config keys, Key Vault secret names, and behaviors are defined once in
-[CONTRACT.md](CONTRACT.md).
+A high-level guide to setting up, securing, and deploying the External Phone Provider OTP Function. The
+steps are the same for every language (`javascript/`, `dotnet/`, `python/`); only the build/run commands
+differ (see each language's README). All config keys, Key Vault secret names, and behaviors are defined
+once in [CONTRACT.md](CONTRACT.md).
 
 ## 1. Pick a language and a provider
 

dotnet/README.md

@@ -1,6 +1,6 @@
-# CYOT Function — C# (.NET isolated worker)
+# External Phone Provider Function — C# (.NET isolated worker)
 
-A C# implementation of the CYOT OTP-delivery Function, conforming to the shared
+A C# implementation of the External Phone Provider OTP-delivery Function, conforming to the shared
 [contract](../docs/CONTRACT.md). Same design as the [`javascript/`](../javascript/) version:
 one dispatch engine + drop-in provider adapters, env-provisioned config, secrets in Key Vault.
 

javascript/README.md

@@ -1,4 +1,4 @@
-# CYOT — Azure Function (delivery endpoint)
+# External Phone Provider — Azure Function (delivery endpoint)
 
 An Azure Function (Node.js) that receives an OTP dispatch request and forwards it to a telephony
 provider (**Infobip**, **Telesign**, **Sinch**, or **Soprano**).
@@ -29,7 +29,7 @@ func azure functionapp publish <your-function-app-name>
 
 ## Configuration
 
-CYOT is **plug-and-play by provider**. The **shared infrastructure** — token validation, dispatch,
+The endpoint is **plug-and-play by provider**. The **shared infrastructure** — token validation, dispatch,
 response normalization, message templating, and
 logging — is identical for every provider and needs no per-provider code. You **choose one provider**;
 the only provider-specific parts are its **adapter** (the outbound API call) and the **few settings** below.
@@ -155,7 +155,7 @@ The engine handles the rest — provider resolution, Key Vault credential fetch
 
 ## Request contract
 
-`POST /api/SendOtp` — the SAS → CYOT delivery endpoint. The cleartext body is a routing envelope; the
+`POST /api/SendOtp` — the SAS → External Phone Provider delivery endpoint. The cleartext body is a routing envelope; the
 PII (phone + rendered message, which contains the passcode) is encrypted in a JWE. See
 [../docs/CONTRACT.md](../docs/CONTRACT.md) for the full contract.
 

python/README.md

@@ -1,6 +1,6 @@
-# CYOT Function — Python (v2 model)
+# External Phone Provider Function — Python (v2 model)
 
-A Python implementation of the CYOT OTP-delivery Function, conforming to the shared
+A Python implementation of the External Phone Provider OTP-delivery Function, conforming to the shared
 [contract](../docs/CONTRACT.md). Same design as the [`javascript/`](../javascript/) and
 [`dotnet/`](../dotnet/) versions: one dispatch engine + drop-in provider adapters, env-provisioned
 config, secrets in Key Vault.