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Claude Desktop is Tools tier. The universal installer writes an HTTP MCP entry with a bearer token. It does not install capture hooks, skills, or an instructions file. Recall and capture are explicit tool calls. Stdio (crystal-mcp) is an optional compatibility path. It is not what the installer writes, and it is not required.

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Agent Instructions

Paste this into Claude Desktop:
Add --backend local or -Backend local for local data storage. See Local-First Setup. You can also pass --targets generic-mcp. See Support Tiers.

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Config path

The installer updates mcpServers.memory-crystal in the file for your OS: The entry shape is HTTP, not a local command:
For a local backend the URL is http://127.0.0.1:3211/api/mcp. Restart Claude Desktop after the file changes.

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Optional stdio compatibility

Use this only when you want the command-launched package. Install the command first with npm install -g @memorycrystal/mcp-server, or build the package locally and put its executable on PATH. Running npx once does not install crystal-mcp globally. CRYSTAL_MCP_MODE=stdio is already the default. Set it when you want the mode explicit. The hosted account URL is https://convex.memorycrystal.ai.
That process exposes 30 tools, including crystal_edit and the research tools. The HTTP entry above exposes the 23 hosted tools. See MCP Server.

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Tools

Call crystal_recall for durable memory and crystal_query_knowledge_base for a named knowledge base. Call crystal_search_messages for exact prior wording. Pass agentId, channel, projectId, or repoSlug when you know them. They partition one account. See Scoping.

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Troubleshooting

Restart Desktop after changing its configuration. Check the OS-specific path above if the server does not appear. The installer registers HTTP; only use the command example when you deliberately choose stdio compatibility. For HTTP authentication failures, check the Bearer header and whether the API key belongs to the selected backend. For a command-not-found error, install crystal-mcp and confirm the desktop process can find it on PATH. An HTTP connection does not need that executable. Neither setup adds automatic capture hooks to Desktop.

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Detect clients automatically

Omit --targets to detect installed clients and choose which ones to configure:
The installer offers cloud, local, and external backend choices and backs up config files before writing them. For OpenClaw, native plugin installation is the cloud Bash path; other backend choices use generic MCP guidance.