# Using The MCP Server > Use when calling LLM APIs through the liter-llm MCP server's 22 tools, and to decide when MCP beats the CLI or SDK. Covers the tool surface, the auto-installing launcher, and authentication. - Skill: `kreuzberg-dev/using-the-mcp-server` (Agent Skill) - Install (CLI): `npx skillmds@latest add kreuzberg-dev/using-the-mcp-server` - Raw SKILL.md: https://api.skillmd.com/api/skills/kreuzberg-dev/using-the-mcp-server/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML, Web & Frontend - Author: kreuzberg-dev (https://skillmd.com/u/kreuzberg-dev) - Updated: 2026-09-10 - Page: https://skillmd.com/skills/kreuzberg-dev/using-the-mcp-server --- # Using the MCP Server The `liter-llm` MCP server exposes 22 tools that mirror the proxy's REST endpoints, so an MCP-compatible client (Claude Code, Claude Desktop) can call 143 LLM providers as tools with no glue code. ## How it runs in this plugin The plugin auto-registers the server. Its command is the bundled launcher `scripts/mcp-launch.sh`, which execs `liter-llm mcp --transport stdio`. On first run the launcher resolves a `liter-llm` binary: it reuses one on `PATH`, then tries `npx`/`uvx`, then Homebrew, then downloads a checksum-verified prebuilt from the tool's latest GitHub release. Override with `LITER_LLM_LAUNCHER=auto|npx|uvx|brew|download`. To run it manually: ```bash liter-llm mcp --transport stdio # for Claude Code / Claude Desktop liter-llm mcp --transport http --port 3001 ``` ## The 22 tools Modality tools: `chat`, `embed`, `generate_image`, `speech`, `transcribe`, `moderate`, `rerank`, `search`, `ocr`. Model listing: `list_models`. File operations: `create_file`, `list_files`, `retrieve_file`, `delete_file`, `file_content`. Batch operations: `create_batch`, `list_batches`, `retrieve_batch`, `cancel_batch`. Responses API: `create_response`, `retrieve_response`, `cancel_response`. ## Authentication stdio has no per-request auth headers, so the server binds auth once at startup via `[mcp]` config: set `mcp.stdio_key_id` to bind a specific virtual key, or `mcp.stdio_trust_local = true` for fully trusted local environments. Provider keys still come from env vars. ## When to prefer MCP over the CLI or SDK - **Prefer MCP** inside an agent session: the agent invokes tools directly, with no code to write or process to manage. - **Prefer the SDK** when building application software in a specific language. - **Prefer the proxy** when many apps or teams need a shared OpenAI-compatible endpoint with keys, budgets, and rate limits.