Process mining API extract fails with Model Context Protocol

BPM Microsoft Power Platform
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1

We upgraded our process mining environment to use the dynamic MCP server last week, and now API-based data extraction is completely broken. Getting permission denied errors when trying to pull analytics data through our automated pipeline.

The API calls worked perfectly before the upgrade. We’re using service principal authentication with the same credentials, but now every request fails with 403 Forbidden. The error mentions something about missing context headers, but the documentation doesn’t explain what’s changed.


HTTP/1.1 403 Forbidden
{"error": "MCP_CONTEXT_REQUIRED",
 "message": "Request missing required MCP context header"}

Our analytics dashboard hasn’t updated in 5 days and business teams are escalating. Has anyone dealt with MCP context requirements after upgrading? What permissions need to be adjusted for service principals?

2

We had to completely refactor our API integration after this change. The old direct API approach doesn’t work anymore. You need to establish an MCP session first, then use that session context for subsequent calls. It’s more secure but definitely breaks existing automation scripts.

3

Thanks for the pointers. I found the new role assignment section, but I’m still confused about the context header format. What exactly needs to be included in the MCP context header? Is it just an environment ID or does it need authentication tokens as well?

4

I went through the entire migration process last month and documented everything. Here’s what you need to do to fix the permission denied errors:

1. MCP Context Header Requirement The new MCP server requires explicit context propagation in all API requests. You must include the X-MCP-Context header with both environment ID and session token:


X-MCP-Context: env=prod-analytics-01;session={token}
Authorization: Bearer {service_principal_token}

Get the session token by calling the MCP handshake endpoint first: POST /api/mcp/v1/sessions with your service principal credentials. The session token is valid for 8 hours.

2. Service Principal Role Assignment The permission model changed completely in Wave 2. Your service principal needs THREE specific roles:

  • “Process Mining Data Reader” (environment-level, for data access)
  • “MCP Session Manager” (tenant-level, for context establishment)
  • “Dataverse API User” (environment-level, for underlying data queries)

Assign these in Azure AD > App Registrations > your app > API Permissions. Don’t forget to grant admin consent after adding them.

3. API Permission Model Changes The legacy “Analytics Reader” role is deprecated and no longer works with MCP-enabled environments. All API calls now flow through the MCP gateway which enforces:

  • Mandatory context headers on every request
  • Environment-scoped sessions (can’t query across environments with one session)
  • Token refresh requirements (sessions expire, can’t be extended)

Update your API client code to handle the session lifecycle. Establish session at start, refresh every 7 hours, and include context headers on all data extraction calls.

Additional Configuration In the Power Platform admin center, verify your environment has “MCP API Access” enabled under Settings > Features. Some environments have this disabled by default after upgrade. Also check the API diagnostics endpoint (GET /api/mcp/v1/diagnostics) to verify your service principal is recognized by the MCP gateway.

After making these changes, your automated pipeline should work again. The 403 errors will clear once the context headers and role assignments are correct.

5

Check your service principal role assignments in the Azure portal. After MCP updates, you need the “Process Mining Data Reader” role explicitly assigned at the environment level, not just the legacy “Analytics Reader” role. The permission model changed significantly - MCP enforces stricter boundary controls. Also verify the app registration has API permissions for Dataverse with delegated access scope.

6

The MCP context header structure is documented in the API reference under authentication patterns. You need to include both the environment context and the MCP session identifier. Format is: X-MCP-Context: env={environmentId};session={sessionToken}. The session token comes from an initial handshake call to the MCP endpoint. Without this, the API gateway can’t route requests properly through the new context isolation layer.