frugal

Tool calls are the new tokens.

For most agentic workloads the tool bill exceeds the model bill. Frugal is an MCP server that routes every tool call your agent makes to the cheapest provider that returns a result — free / local first, paid only as fallback, premium only when you opt in.

Works with any model. One signed Go binary. Your keys. No account. Source-available (BUSL 1.1 → Apache 2.0).

frugal.sh

Install

curl -fsSL https://frugal.sh/install | bash
frugal mcp install

The first command drops the binary in your $PATH. The second auto-detects Claude Desktop, Cursor, and Claude Code and merges frugal into each configured MCP server list.

Try it now (no keys)

Search and extract work out of the box — Marginalia (free, public web index) and go-readability (free, pure-Go local extractor) ship enabled with zero configuration. Restart your agent and ask it something:

> recent AI news?
  frugal__search → marginalia (free, no key)
  gpt-4.1-nano synthesizes · $0.0006
done. total: $0.0006 — zero search cost.

Tool call: free. The rack-rate gap is the gap you keep.

Set your keys (optional)

Add keys to unlock cheaper paid providers. Frugal reads them from your environment and only registers tools whose providers are configured:

# Search — frugal__search
export SEARXNG_URL=...           # free, self-hosted (also Marginalia free, no key)
export SERPER_API_KEY=...        # cheap paid
export YDC_API_KEY=...           # premium paid (You.com)

# Extract — frugal__extract (goreadability is free, no key)
export FIRECRAWL_API_KEY=...     # premium paid (JS-rendered pages)

# Browse — frugal__browse
export BROWSERLESS_TOKEN=...     # headless render

That's it. Restart your agent. frugal__search, frugal__extract, and frugal__browse show up in the tool picker (only the tools whose providers are configured get registered).

The rack-rate gap

Tool prices haven't fallen the way model prices have. You.com at $0.005/call is 5× Serper at $0.001/call. SearXNG, running on your own machine, is free.

Frugal walks the columns left to right. Each tool call goes to the leftmost configured provider that returns a result; you keep the gap.

What ships today

One MCP server, three tools, seven providers:

• frugal__search — shipping. Routed across SearXNG (free, self-hosted), Marginalia (free, public), Serper ($0.001/call), and You.com ($0.005/call).
• frugal__extract — shipping. Routed across go-readability (free, pure-Go local Readability) and Firecrawl (~$0.001/page, JS-rendered).
• frugal__browse — partial. Browserless (~$0.002/render, headless Chrome) shipping; local Playwright deferred.
• Stdio + Streamable HTTP transports.
• HTTP transport supports bearer-token auth (FRUGAL_AUTH_TOKEN), per-IP rate limiting, and a /metrics endpoint (Prometheus text: frugal_calls_total{tool=,provider=} etc.).
• frugal mcp install writes the right config into Claude Desktop, Cursor, and Claude Code.

What's coming

• Phase 3 — embeddings, transcription, code execution, local chat models, semantic cache.
• Phase 4 — Frugal Cloud: hosted MCP endpoint for users who don't want to operate the local stack themselves.

From source

git clone https://github.com/brainsparker/frugal.git && cd frugal && make build

License

BUSL 1.1 — self-hosting and internal commercial use are permitted. Each release converts to Apache 2.0 four years after publication. Plain-English summary in LICENSE-BUSL-FAQ.md.

Security

Private vulnerability reports via GitHub Security Advisories. Full policy in SECURITY.md.