Power Platform Community Forum Thread Details

Environment:

Copilot Studio / Power Platform
GitHub MCP Server (remote endpoint: https://api.githubcopilot.com/mcp/)
Authentication: Personal Access Token (PAT)

Problem:

When configuring the GitHub MCP server in Copilot Studio using a PAT, I receive the following error:
- Content-Type must be 'application/json'\n

Categories:

Model context protocol

Hi @YK-20041934-0,

You can’t fix this with headers or a PAT.

Why it fails:

Copilot Studio calls MCP tools using a stateless HTTP POST and expects a single JSON response.
GitHub’s hosted MCP endpoint is designed for IDEs (VS Code, Cursor) and requires a stateful Server‑Sent Events (SSE) stream.

When Copilot Studio sends a one‑off POST, GitHub rejects the transport model, and the gateway surfaces a misleading
Content-Type must be 'application/json' error.

What works instead:

Add an adapter (bridge) e.g., an Azure Function that:

Accepts the stateless POST from Copilot Studio
Manages the SSE session with GitHub MCP
Flattens the stream into a single JSON response

Or skip MCP, use the native GitHub REST or GraphQL APIs (built‑in or custom connector), which are fully compatible with Copilot Studio.

In short: this is a transport mismatch (stateless REST vs stateful SSE), not a configuration issue.

References:
The Protocol Paradox: Why GitHub MCP Fails to Integrate with Copilot Studio

How to Fix the "Content-Type must be application/json" Error in Copilot Studio MCP

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