chore: update docs for pre-call data fetch

api/services/pipecat/pre_call_fetch.py

@@ -15,6 +15,29 @@ from api.utils.credential_auth import build_auth_header
 PRE_CALL_FETCH_TIMEOUT_SECONDS = 10
 
 
+def _extract_initial_context(response_data: Dict[str, Any]) -> Dict[str, Any]:
+    """Pull the context variables out of a pre-call fetch response.
+
+    The canonical key is ``initial_context``. The legacy ``dynamic_variables``
+    key is still accepted for backward compatibility, so existing endpoints
+    keep working; ``initial_context`` takes precedence when both are present.
+
+    Either key may appear at the top level or nested under ``call_inbound``:
+        {"call_inbound": {"initial_context": {...}}} | {"initial_context": {...}}
+        {"call_inbound": {"dynamic_variables": {...}}} | {"dynamic_variables": {...}}
+    """
+    container = response_data.get("call_inbound")
+    if not isinstance(container, dict):
+        container = response_data
+
+    for key in ("initial_context", "dynamic_variables"):
+        value = container.get(key)
+        if isinstance(value, dict):
+            return value
+
+    return {}
+
+
 async def execute_pre_call_fetch(
     *,
     url: str,
@@ -77,24 +100,16 @@ async def execute_pre_call_fetch(
                     )
                     return {}
 
-                # Extract dynamic_variables from Retell-compatible response
-                # Supports: {call_inbound: {dynamic_variables: {...}}}
-                #       or: {dynamic_variables: {...}}
-                dynamic_vars = {}
-                call_inbound = response_data.get("call_inbound")
-                if isinstance(call_inbound, dict):
-                    dynamic_vars = call_inbound.get("dynamic_variables", {})
-                elif "dynamic_variables" in response_data:
-                    dynamic_vars = response_data["dynamic_variables"]
-
-                if not isinstance(dynamic_vars, dict):
-                    dynamic_vars = {}
+                # Extract the variables to merge into initial_context. Prefers
+                # the canonical `initial_context` key, falling back to the
+                # legacy `dynamic_variables` key for backward compatibility.
+                initial_context_vars = _extract_initial_context(response_data)
 
                 logger.info(
                     f"Pre-call fetch: success ({response.status_code}), "
-                    f"dynamic_variables keys: {list(dynamic_vars.keys())}"
+                    f"initial_context keys: {list(initial_context_vars.keys())}"
                 )
-                return dynamic_vars
+                return initial_context_vars
             else:
                 logger.warning(
                     f"Pre-call fetch: HTTP {response.status_code} - "

api/tests/test_pre_call_fetch.py

@@ -0,0 +1,66 @@
+from api.services.pipecat.pre_call_fetch import _extract_initial_context
+
+
+class TestExtractInitialContext:
+    """Tests for _extract_initial_context, the pre-call fetch response parser."""
+
+    def test_initial_context_nested_under_call_inbound(self):
+        """The canonical `initial_context` key nested under `call_inbound`."""
+        response = {"call_inbound": {"initial_context": {"customer_name": "Jane"}}}
+        assert _extract_initial_context(response) == {"customer_name": "Jane"}
+
+    def test_initial_context_at_top_level(self):
+        """The canonical `initial_context` key at the top level."""
+        response = {"initial_context": {"customer_name": "Jane"}}
+        assert _extract_initial_context(response) == {"customer_name": "Jane"}
+
+    def test_legacy_dynamic_variables_nested(self):
+        """The legacy `dynamic_variables` key still works nested under `call_inbound`."""
+        response = {"call_inbound": {"dynamic_variables": {"customer_name": "Jane"}}}
+        assert _extract_initial_context(response) == {"customer_name": "Jane"}
+
+    def test_legacy_dynamic_variables_at_top_level(self):
+        """The legacy `dynamic_variables` key still works at the top level."""
+        response = {"dynamic_variables": {"customer_name": "Jane"}}
+        assert _extract_initial_context(response) == {"customer_name": "Jane"}
+
+    def test_initial_context_takes_precedence_over_legacy(self):
+        """When both keys are present, `initial_context` wins."""
+        response = {
+            "call_inbound": {
+                "initial_context": {"source": "new"},
+                "dynamic_variables": {"source": "legacy"},
+            }
+        }
+        assert _extract_initial_context(response) == {"source": "new"}
+
+    def test_falls_back_to_legacy_when_initial_context_not_a_dict(self):
+        """A non-dict `initial_context` falls back to `dynamic_variables`."""
+        response = {
+            "initial_context": None,
+            "dynamic_variables": {"customer_name": "Jane"},
+        }
+        assert _extract_initial_context(response) == {"customer_name": "Jane"}
+
+    def test_nested_values_preserved(self):
+        """Nested objects pass through untouched for dot-notation access."""
+        response = {
+            "call_inbound": {
+                "initial_context": {"customer": {"address": {"city": "LA"}}}
+            }
+        }
+        assert _extract_initial_context(response) == {
+            "customer": {"address": {"city": "LA"}}
+        }
+
+    def test_empty_when_no_known_keys(self):
+        """A response with neither key yields an empty dict."""
+        assert _extract_initial_context({"call_inbound": {"agent_id": 1}}) == {}
+
+    def test_empty_when_call_inbound_missing(self):
+        """No `call_inbound` and no top-level keys yields an empty dict."""
+        assert _extract_initial_context({}) == {}
+
+    def test_non_dict_vars_yield_empty(self):
+        """A non-dict value under a known key yields an empty dict."""
+        assert _extract_initial_context({"initial_context": "nope"}) == {}

docs/core-concepts/context-and-variables.mdx

@@ -18,20 +18,10 @@ initial_context ──► Agent ──► gathered_context
 
 Data available to the agent before the call starts — the contact's name, account details, appointment information, anything the agent should know upfront. It can be set from several places:
 
-- **API trigger** — pass it in the request body when calling `POST /public/agent/{uuid}` or `POST /telephony/initiate-call`
-- **Campaign CSV** — columns beyond `phone_number` automatically become `initial_context` fields for each contact's call
-- **Dashboard** — set default template context variables on the agent, used when no external context is provided
-
-```json
-{
-  "phone_number": "+14155550100",
-  "initial_context": {
-    "customer_name": "Jane Smith",
-    "plan": "premium",
-    "renewal_date": "April 1"
-  }
-}
-```
+- **[API trigger](/voice-agent/api-trigger)** — pass it in the request body when calling `POST /public/agent/{uuid}` or `POST /telephony/initiate-call`
+- **[Campaign CSV](/core-concepts/campaigns)** — columns beyond `phone_number` automatically become `initial_context` fields for each contact's call
+- **[Pre-call data fetch](/voice-agent/pre-call-data-fetch)** — enrich the context with data from your CRM or ERP via an HTTP call as the call starts, before the agent speaks
+- **[Agent Settings](/voice-agent/template-variables#using-template-variables-for-testing)** — set template context variables on the agent for testing; they're included in test calls from the workflow editor and ignored on production calls
 
 ### Template variables
 
@@ -103,7 +93,7 @@ Data the agent collects *during* the call. You configure what to extract in the
 
 <img src="../images/extracted_variables.png" alt="Extracted variables" style={{border: "1px solid #d1d5db", borderRadius: "8px", maxWidth: "100%"}} />
 
-`gathered_context` is returned in the run record after the call completes and is available in [webhook payloads](/developer/webhooks) for downstream processing.
+`gathered_context` is returned in the run record after the call completes and is available in [webhook payloads](/developer/webhooks) for downstream processing. It is **not** available as a template variable in Agent prompts — prompts can only reference `initial_context` fields.
 
 ## Data flow example
 

docs/voice-agent/api-trigger.mdx

@@ -118,7 +118,7 @@ For example, if your request includes:
 }
 ```
 
-You can reference the user's name in your prompt as `{{initial_context.user.name}}`.
+You can reference the user's name in your agent prompt as `{{user.name}}` — in Agent prompts, `initial_context` fields are referenced directly by name (not prefixed with `initial_context.`). See [template variables](/voice-agent/template-variables) for the exact syntax in prompts versus webhook payloads.
 
 See [Context & Variables](/core-concepts/context-and-variables) for more on how data flows through a call.
 

docs/voice-agent/pre-call-data-fetch.mdx

@@ -11,7 +11,7 @@ Pre-Call Data Fetch allows you to enrich the call context with external data bef
 1. A call arrives (inbound) or is initiated (outbound).
 2. Dograh sends a **POST** request to your configured endpoint with a standardized payload.
 3. The caller hears a ring-back tone while waiting for the response.
-4. Your API responds with a JSON object containing `dynamic_variables`.
+4. Your API responds with a JSON object containing an `initial_context` object.
 5. The variables are merged into the call's initial context.
 6. The voice agent starts with full access to the fetched data via `{{variable_name}}` syntax.
 
@@ -50,12 +50,12 @@ The `Content-Type` header is set to `application/json`. If you configured a cred
 
 ## Expected Response Format
 
-Your API should return a **JSON object** with a `2xx` status code. The variables to inject into the call context should be placed inside the `dynamic_variables` key:
+Your API should return a **JSON object** with a `2xx` status code. The variables to inject into the call context should be placed inside the `initial_context` key:
 
 ```json
 {
   "call_inbound": {
-    "dynamic_variables": {
+    "initial_context": {
       "customer_name": "Jane Doe",
       "account_status": "active",
       "loyalty_tier": "gold",
@@ -65,34 +65,38 @@ Your API should return a **JSON object** with a `2xx` status code. The variables
 }
 ```
 
-You can also place `dynamic_variables` at the top level:
+You can also place `initial_context` at the top level:
 
 ```json
 {
-  "dynamic_variables": {
+  "initial_context": {
     "customer_name": "Jane Doe",
     "account_status": "active"
   }
 }
 ```
 
+<Note>
+The legacy `dynamic_variables` key is still accepted as a drop-in alias for `initial_context`, so existing integrations keep working without any changes. Use `initial_context` for new integrations. If a response contains both keys, `initial_context` takes precedence.
+</Note>
+
 After the response is received, you can reference these values anywhere template variables are supported:
 
 - **Greeting**: `Hello {{customer_name}}, thank you for calling!`
 - **Prompt**: `The customer is a {{loyalty_tier}} member with {{open_tickets}} open support tickets.`
 
 <Note>
-If the response is not a valid JSON object, does not contain `dynamic_variables`, or the request fails or times out, the call proceeds normally without the additional context. The pre-call fetch never blocks or fails a call.
+If the response is not a valid JSON object, does not contain `initial_context` (or the legacy `dynamic_variables`), or the request fails or times out, the call proceeds normally without the additional context. The pre-call fetch never blocks or fails a call.
 </Note>
 
 ## Nested Variables
 
-If your `dynamic_variables` contain nested objects, you can access them using dot notation:
+If your `initial_context` contains nested objects, you can access them using dot notation:
 
 ```json
 {
   "call_inbound": {
-    "dynamic_variables": {
+    "initial_context": {
       "customer": {
         "name": "Jane Doe",
         "address": {
@@ -153,7 +157,7 @@ app.post("/dograh/pre-call", async (req, res) => {
 
   res.json({
     call_inbound: {
-      dynamic_variables: {
+      initial_context: {
         customer_name: customer.name,
         account_status: customer.status,
         loyalty_tier: customer.tier,

docs/voice-agent/template-variables.mdx

@@ -4,13 +4,23 @@ description: "You can use Template Variables in your prompts for your Agent node
 ---
 
 ### Template Rendering
-You can reference template variables which is passed as [`initial_context`](/core-concepts/context-and-variables#initial_context) either using the [API Trigger](/voice-agent/api-trigger) or when uploading a Sheet for a [campaign](/core-concepts/campaigns). You can also use any extracted variable as [`gathered_context`](/core-concepts/context-and-variables#gathered_context)
 
-The template rendering can take nested values. 
+You reference template variables with `{{double_brace}}` syntax. The data comes from [`initial_context`](/core-concepts/context-and-variables#initial_context) — set via the [API Trigger](/voice-agent/api-trigger), a [campaign](/core-concepts/campaigns) sheet, or a [Pre-Call Data Fetch](/voice-agent/pre-call-data-fetch) that enriches the context when the call starts — and, in Webhook payloads only, from [`gathered_context`](/core-concepts/context-and-variables#gathered_context) (variables extracted during the call).
 
-Example: If the initial context is
+**The syntax depends on where you use it:**
 
-```
+| Where | `initial_context` | `gathered_context` |
+| --- | --- | --- |
+| Agent node prompts | `{{field_name}}` (referenced directly) | Not available |
+| Webhook Node payloads | `{{initial_context.field_name}}` | `{{gathered_context.field_name}}` |
+
+#### Agent node prompts
+
+In an Agent node prompt, reference each `initial_context` field **directly by name**. Nested values are supported with dot notation.
+
+Example: if the initial context is
+
+```json
 {
     "initial_context": {
         "user": {
@@ -20,14 +30,26 @@ Example: If the initial context is
 }
 ```
 
-You can write your prompt to access the user's name as below
+write your prompt to access the user's name as below:
 
-Prompt: `You are Alice, who is talking to {{initial_context.user.name}}.`
+Prompt: `You are Alice, who is talking to {{user.name}}.`
+
+<Note>
+Variables extracted during the call (`gathered_context`) are **not** available in Agent prompts — a prompt can only reference `initial_context` fields. To act on extracted data, send it to a [Webhook Node](/voice-agent/webhook).
+</Note>
+
+#### Webhook Node payloads
+
+When constructing a [Webhook Node](/voice-agent/webhook) payload, the context objects are nested under their names, so reference them with the `initial_context.` and `gathered_context.` prefixes:
+
+Payload value: `{{initial_context.user.name}}` or `{{gathered_context.call_disposition}}`
 
 ### Using Template Variables for Testing
 
 Template variables defined in your workflow **Settings > Context Variables** are included in test calls (both web and phone) made from the workflow editor. This is useful for simulating data that would normally come from telephony or an API trigger.
 
+<img src="../images/template-variables.png" alt="Template Variables panel in workflow Settings, showing a customer_name variable and fields to add new key/value pairs" style={{border: "1px solid #d1d5db", borderRadius: "8px", maxWidth: "100%"}} />
+
 For example, you can set `caller_number` and `called_number` as context variables to test [Pre-Call Data Fetch](/voice-agent/pre-call-data-fetch#testing-with-test-calls) without needing a real inbound call.
 
 <Note>