MCPSpendCompare · Lunary
MCPSpend vs. Lunary
Lunary is a solid open-source LLM monitoring + prompt management platform — strong on prompt versioning, user feedback loops, and offline evals. MCPSpend is something different: zero-code installation purpose-built for the MCP tool layer, with opinionated cost dashboards out of the box. Lunary requires SDK instrumentation in your agent code; MCPSpend works without touching it.
| Dimension | MCPSpend | Lunary |
|---|---|---|
| Product category | AI cost observability (MCP-native) | Open-source LLM monitoring, prompt management, evals, user feedback |
| Primary unit tracked | MCP tool call (server + tool + cost + latency) | LLM completion (prompt → response, with optional user feedback) |
| Install path | One CLI command — auto-detects Cursor, Claude Desktop, Windsurf, VS Code, Claude Code | Install lunary SDK, wrap each LLM call with Lunary handlers |
| MCP tool call visibility | Native — every call decoded automatically | Manual — you instrument each tool invocation as a Lunary event |
| Works in closed IDEs (Cursor, Claude Desktop) | Yes — config-only wrap | No — requires SDK instrumentation inside the agent code |
| Prompt versioning & template management | Not in scope | Core feature |
| User feedback loops & evals | Not in scope | Core feature |
| Dollar budget + alerts | $ budget at 50/80/100% via email + Slack out of the box | Cost tracking present; alerting depends on integration setup |
| Per-MCP-server cost breakdown | Built-in dashboard | Not modelled — build with metadata |
| Self-hosted core | Proxy + MCP server MIT on npm | Fully open-source, Docker-deployable |
| Free tier (managed) | 25,000 tool calls / month forever | 1,000 LLM events / month free (cloud) |
| Paid entry point | $29 / month (Pro) | Self-host free; managed cloud from ~$20 / month |
Choose MCPSpend if…
- ✓ Your agents live in IDEs you don't control the source of
- ✓ You want first-class MCP cost dashboards without writing SDK code
- ✓ $ budget + Slack alerts are required day one
- ✓ EU-hosted + GDPR Art. 15/17/20 self-serve matters
Choose Lunary if…
- ✓ Prompt versioning + template management is a top use case
- ✓ You want user-feedback loops tied to specific LLM completions
- ✓ Offline evaluations / regression tests on prompts matter
- ✓ You prefer a fully open-source, self-hostable stack
They're complementary.
Lunary handles prompts, evals, and user feedback. MCPSpend handles MCP tool cost attribution. Different layers, both useful.