Claude Desktop
claude_desktop_config.jsonthat bridges to Prism's gateway over stdio.Last updated Reviewed against Prism v0.3.26
What Claude Desktop can and cannot do
| Capability | Supported |
|---|---|
| Model provider base URL override | No. Claude Desktop uses Anthropic's models only. |
| MCP servers via claude_desktop_config.json | Yes. |
| Remote (HTTP) MCP servers directly | No. Claude Desktop launches stdio servers only — a bridge is required. |
Config file location
| Platform | Path |
|---|---|
| Windows | %APPDATA%\Claude\claude_desktop_config.json |
| macOS | ~/Library/Application Support/Claude/claude_desktop_config.json |
| Linux | ~/.config/Claude/claude_desktop_config.json |
Prism does not detect or write this file, so it is a manual edit. Quit Claude Desktop completely before editing — it overwrites the file on exit.
Setup
Enable your servers in Prism
Quit Claude Desktop
Add one bridge entry
Reopen Claude Desktop
mcp__<server>__<tool>.{
"mcpServers": {
"prism": {
"command": "npx",
"args": [
"-y",
"mcp-remote",
"http://127.0.0.1:11434/mcp",
"--header",
"Authorization: Bearer prism"
]
}
}
}Why a bridge is needed
Prism serves MCP over Streamable HTTP, which is what every modern MCP client prefers. Claude Desktop only spawns local processes and speaks to them over stdin and stdout, so the entry above launches a small stdio-to-HTTP bridge that opens one connection to Prism and relays messages both ways.
| Piece | Role |
|---|---|
| command: npx | Claude Desktop launches this locally, which is what it knows how to do. |
| mcp-remote | The bridge that speaks stdio to Claude Desktop and HTTP to Prism. |
| The URL | Prism's aggregate gateway, so every enabled server is reachable. |
| The header | Prism's fixed token. Upstream MCP credentials never reach Claude Desktop. |
http://127.0.0.1:11434/mcp/<agent>and grant that agent id only the servers you want in the MCP tab's Agent access panel. The gateway then rejects calls to anything outside that allowlist.Alternative: no bridge
If you would rather not run a bridge, add each MCP server directly to claude_desktop_config.json as its own stdio entry. You lose the shared credentials, the per-agent allowlist and the health reporting, and every agent that needs the same server needs its own copy of the configuration.
| Approach | Trade-off |
|---|---|
| One Prism bridge entry | One entry, credentials held once by Prism, per-agent allowlists, adds a bridge process. |
| One entry per server | No bridge, but credentials duplicated and no allowlist or health view. |
Verify
# Confirm the gateway itself is healthy before blaming the bridge curl http://127.0.0.1:11434/mcp/status -H "Authorization: Bearer prism"
A server stuck in needs_auth or runtime_missing will show no tools in Claude Desktop. Fix it in the MCP tab first. See Troubleshooting.