Files
coder/coderd
Kyle Carberry f784b230ba fix(coderd/x/chatd/mcpclient): handle EmbeddedResource and ResourceLink in MCP tool results (#23569)
## Problem

When an MCP tool returns an `EmbeddedResource` content item (e.g. GitHub
MCP server returning file contents via `get_file_contents`), the
`convertCallResult` function falls through to the `default` case,
producing:

```
[unsupported content type: mcp.EmbeddedResource]
```

This loses the actual resource content and shows an unhelpful message in
the chat UI.

## Root Cause

The type switch in `convertCallResult` handles `TextContent`,
`ImageContent`, and `AudioContent`, but not the other two `mcp.Content`
implementations from `mcp-go`:
- `mcp.EmbeddedResource` — wraps a `ResourceContents` (either
`TextResourceContents` or `BlobResourceContents`)
- `mcp.ResourceLink` — contains a URI, name, and description

## Fix

Add two new cases to the type switch:

1. **`mcp.EmbeddedResource`**: nested type switch on `.Resource`:
   - `TextResourceContents` → append `.Text` to `textParts`
- `BlobResourceContents` → base64-decode `.Blob` as binary (type
`"image"` or `"media"` based on MIME)
   - Unknown → fallback `[unsupported embedded resource type: ...]`

2. **`mcp.ResourceLink`**: render as `[resource: Name (URI)]` text

## Testing

Added 3 new test cases (all passing, full suite 23/23 PASS):
- `TestConnectAll_EmbeddedResourceText` — text resource extraction
- `TestConnectAll_EmbeddedResourceBlob` — binary blob decoding
- `TestConnectAll_ResourceLink` — resource link rendering
2026-03-25 12:31:17 +00:00
..