How to pass a variable from a Power Apps canvas app into a Copilot Studio agent (Chatbot control)?

Question

How to pass a variable from a Power Apps canvas app into a Copilot Studio agent (Chatbot control)?

Palaparthi Krishna (US) 20

Title: How to pass a variable from a Power Apps canvas app into a Copilot Studio agent (Chatbot control)?

Environment / setup:

Power Apps Canvas app with an embedded Chatbot control (Chatbot@0.1.12), connected to a Copilot Studio agent via EnvironmentId + SchemaName.
Copilot Studio agent has a global variable "selectedIndustry" with "External sources can set values" turned ON. The agent is published.
The app has an industry dropdown. When the user changes it, I want the agent to use that industry.

What I want:

When the dropdown changes, the agent should use the newly selected industry value in its topics/prompts (it drives which data the agent returns).

What I have tried:

I set the Chatbot control's Endpoint property to my agent's token endpoint with a query string appended, e.g.: https://<...>.environment.api.powerplatform.com/copilotstudio/dataverse-backed/authenticated/bots/<botname>/conversations?api-version=2022-03-01-preview&selectedIndustry=Consumer%20Market Result: [describe what happened — e.g., "the agent did not pick up the value" / "Global.selectedIndustry stayed blank"].
I removed the node in ConversationStart that was setting selectedIndustry to blank, so it no longer clears the external value.

Questions:

Does the Chatbot control's Endpoint property support passing a Copilot Studio external/global variable via a query-string parameter? If yes, what is the exact expected URL format?
If not, what is the supported way to pass a variable from a canvas app into an embedded Copilot Studio agent at conversation start?
Is there a supported way to update the variable when the dropdown changes mid-session, or must the chat session be restarted?
Given the Chatbot/Copilot canvas controls are being deprecated (Feb 2, 2026), what is the recommended replacement for embedding an agent in a canvas app AND passing context into it?

Thanks in advance.

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Answer 1

Michelle-N 20,735 Microsoft External Staff Moderator

Hi @Palaparthi Krishna (US)

Based on the detailed configuration you shared, I understand that you are trying to pass a dynamic contextual variable (selectedIndustry) from a Power Apps canvas app dropdown into an embedded Copilot Studio agent. While you have correctly configured the agent's global variable to accept external values ("External sources can set values" turned ON) and removed any conflicting logic in ConversationStart, appending the variable as a query string parameter to the Chatbot control's Endpoint property is not causing the agent to pick up the value.

Here is the technical breakdown of why this approach is failing and the recommended steps to implement a supported, future-proof solution.

-I have not found Microsoft documentation indicating that appending query-string parameters to the Chatbot control Endpoint property is a supported mechanism for setting Copilot Studio global variables. While appending query strings directly to an embed URL works for standard custom website deployments, the native Power Apps Chatbot control acts as a restrictive wrapper around Web Chat. It handles authentication and endpoint routing internally, and it does not parse, forward, or expose URL query parameters into Copilot Studio global variables.

-For traditional custom web environments, Microsoft officially documents two ways to initialize external global variables:

Query Strings (For standard iframe embeds): You can append the parameter directly to the default agent web-chat URL schema: https://web.powerva.microsoft.com/webchat/bots/<botId>?selectedIndustry=Consumer%20Market
Backchannel Events (For Custom React Web Chat): For custom deployments, Microsoft recommends injecting a custom event (pvaSetContext) into the Web Chat Redux store upon connection:

const store = WebChat.createStore(
 {},
 ({ dispatch }) =>
 next =>
 action => {
 if (action.type === "DIRECT_LINE/CONNECT_FULFILLED") {
 dispatch({
 type: "WEB_CHAT/SEND_EVENT",
 payload: {
 name: "pvaSetContext",
 value: {
 selectedIndustry: "Consumer Market"
 }
 }
 });
 }
 return next(action);
 }
);

However, within a Canvas App utilizing the default Chatbot Control, you do not have access to JavaScript APIs, Web Chat middleware, or the underlying store to dispatch events directly. Therefore, you cannot natively pass variables at conversation start or update them mid-session using the built-in control.

-In a Power Apps canvas app, the built-in Chatbot control does not appear to expose the WebChat middleware/event layer needed to dynamically send context variables when a dropdown changes. Therefore, changing the dropdown mid-session is not something I would expect to work through the Endpoint property alone. The safer approach is either to restart the chat session with the new context, or move to a custom WebChat/PCF-based component where the canvas app can send a custom event to the Copilot Studio agent.

Also note that the Copilot/Copilot answer controls for canvas apps are being deprecated for new apps starting February 2, 2026. Microsoft recommends Microsoft 365 Copilot in canvas apps for natural-language app experiences. However, if the requirement is specifically to embed an existing Copilot Studio agent and pass custom app context into it, a PCF/WebChat implementation is currently the more suitable approach because it can send startup or runtime events into the agent

Please refer the following document: Add a Copilot control to a canvas app (preview)

I hope this information help.

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Michelle-N 20,735 Reputation points Microsoft External Staff Moderator

2026-07-10T13:49:33.26+00:00

Hi @Palaparthi Krishna (US)

Is there any update from you?

If yes, please feel free to let me know.
Palaparthi Krishna (US) 20 Reputation points

2026-07-10T14:46:34.8033333+00:00
Hi @Michelle-N ,

Thank you for the detailed explanation — that clarifies why the query-string approach on the Chatbot control Endpoint wasn't working, and confirms the built-in control doesn't expose the WebChat/event layer.

For this project we'd prefer to stay entirely within the canvas app screen and avoid a WebChat/PCF custom component for now. Given that constraint, I'd like to confirm whether the following pattern is supported:

On the industry dropdown's OnChange in the canvas app, write the selected industry to a small Dataverse table (one row per user, keyed to the current user), e.g. using Patch().

In the Copilot Studio agent, read that value from Dataverse (a "List rows" / Dataverse action) at Conversation Start — and/or inside each industry topic — filtering on the current user (System.User.PrincipalName), and set Global.selectedIndustry from it.

This keeps all app-side work inside the canvas screen (no WebChat, no PCF) and lets the agent pull the latest selected industry itself.

Could you confirm:

Is this Dataverse-pull pattern a supported way to give the agent the app's selected context without a custom component?

If we read the value inside each topic (not just at Conversation Start), will the agent reflect a dropdown change within the same open session, or does the chat still need to be restarted?

Is there any other fully canvas-native option we may have missed?

Thanks again for your help.
Michelle-N 20,735 Reputation points Microsoft External Staff Moderator

2026-07-13T13:12:28.6466667+00:00
Hi @Palaparthi Krishna (US)

Based on my research, it is not the same as passing context directly into the embedded Chatbot control. Instead, it uses supported platform capabilities on both sides:

-In the canvas app, Patch() is supported for creating or modifying records in a data source, including scenarios where you update specific fields without using a form.

-In Copilot Studio, variables can be used across topics, and variables can also be passed to, and returned from, other topics and Power Automate flows.

-Copilot Studio can call a Power Automate flow to authenticate/connect to an external system, run a query, format results, and return those results to the agent. Microsoft’s example uses Dataverse as the data source for returning records to Copilot Studio.

So the pattern would be:

The canvas app writes the selected industry to a Dataverse table, keyed by the current user.

The Copilot Studio agent reads that value from Dataverse through a Dataverse action or a Power Automate flow.

The agent sets Global.selectedIndustry from the returned value before using it in the topic logic.

Reference: Work with variables

For your second question: if the agent only reads the value at Conversation Start, then it will only have the value available at that point in the conversation. If the dropdown changes after the chat has already started, the agent will not automatically know that the Dataverse row changed unless you explicitly make the agent read the row again. If you read the Dataverse value inside each topic, or at least before each place where the selected industry matters, then the agent can use the latest value returned by that read operation. In that design, the chat session does not necessarily need to be restarted, because the topic is actively re-querying Dataverse and then setting the variable again. However, avoid configuring the variable only as “get value from this node if empty” if your goal is to refresh the value, because that pattern is specifically for retrieving the value when the variable is empty.

Reference: Configure context variables for AI Agents

For the third question, I am not find of another fully canvas-native way to push an arbitrary variable directly into the embedded Chatbot control at runtime. The documented direct context-passing patterns are for supported web chat or custom canvas/WebChat approaches, including query-string variables on the web chat URL or sending a pvaSetContext event through WebChat. The built-in Power Apps Copilot/custom Copilot canvas experiences are also preview capabilities, and Microsoft documentation states that adding these controls/features to new canvas apps is discontinued starting February 2, 2026, with Microsoft 365 Copilot in canvas apps being the recommended direction as it becomes available.

So under your constraint of staying entirely inside the canvas app screen and avoiding WebChat/PCF, the Dataverse-pull pattern is likely the cleanest option:

Canvas app owns and updates the selected context in Dataverse.

Copilot Studio reads the current value when it needs it.

Read once at Conversation Start if the context should be fixed for the session.

Read inside each relevant topic if the context should reflect dropdown changes during the same open session.

Reference: Work with global variables

Thank you.
Michelle-N 20,735 Reputation points Microsoft External Staff Moderator

2026-07-14T14:05:00.9566667+00:00

Hi @Palaparthi Krishna (US)

Is there any update from you?

If yes, please feel free to let me know.
Palaparthi Krishna (US) 20 Reputation points

2026-07-14T14:07:43.3333333+00:00

Hi @Michelle-N ,
Currently I am working on it
i will update once i got the results

Thank you for response .
Michelle-N 20,735 Reputation points Microsoft External Staff Moderator

2026-07-14T14:19:56.7066667+00:00

Hi @Palaparthi Krishna (US)

Thank you. Once you've finished, please let me know.