MCP Cost Optimizer

io.github.petrovicistefanv0.1.1Updated Oct 9, 2026

Local-first LLM cost analysis and model-switch savings estimates for AI agents.

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Overview

AI-generated overview

A local MCP server that estimates LLM API costs from supplied usage records and rate tables, and compares cheaper model scenarios.

What it does
It exposes three tools: estimate_llm_cost for a single request, analyze_llm_usage for costs by model, unpriced models and duplicate-request opportunities, and compare_llm_models for an independent migration scenario against a target model. It works on normalized usage records and a caller-supplied rate table, and reports assumptions rather than changing anything. A CLI can analyze JSON/JSONL files under its current directory.
When to use it
Use it when you already have normalized token-usage records and your own per-model prices and want an assistant to break down spend, flag unknown models, spot repeated requests, or sketch what switching models might save. It is not a live cost monitor and does not observe other API calls.
Requirements
Node.js 20+ for the local server, run over stdio via npx or an absolute path to src/index.js. No account, API key or environment variable is needed for the local server. The optional hosted HTTP mode needs CONTROL_PLANE_URL and an Authorization Bearer token.
Before you install
The local server makes no outbound requests and stores no usage, and its MCP tools cannot read files; the CLI only reads JSON/JSONL under its working directory. Provider prices and currency conversion are not bundled, so you must supply rates yourself. Duplicate savings are an upper bound and comparisons can show negative savings; scenarios must not be added together. The hosted mode sends usage records and rates to that host and requires a bearer token.

Installation

In SourceWeft

  1. Open MCP Cost Optimizer in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

MCP Cost Optimizer

Local-first LLM/API cost analysis for AI agents, developers and teams. MIT licensed. Version 0.1.0 MVP.

Install in your AI client

Works with any MCP client over stdio; no account or API key needed for the local server.

Claude Code

sh
claude mcp add cost-optimizer -- npx -y mcp-cost-optimizer

Codex CLI

sh
codex mcp add cost-optimizer -- npx -y mcp-cost-optimizer

Claude Desktop, Cursor, Windsurf, Cline, Gemini CLI — add to the client's MCP config (claude_desktop_config.json, ~/.cursor/mcp.json, ~/.codeium/windsurf/mcp_config.json, Cline MCP settings, ~/.gemini/settings.json):

json
{  "mcpServers": {    "cost-optimizer": {      "command": "npx",      "args": [        "-y",        "mcp-cost-optimizer"      ]    }  }}

VS Code / GitHub Copilot — .vscode/mcp.json:

json
{  "servers": {    "cost-optimizer": {      "type": "stdio",      "command": "npx",      "args": [        "-y",        "mcp-cost-optimizer"      ]    }  }}

Zed — settings.json:

json
{  "context_servers": {    "cost-optimizer": {      "command": "npx",      "args": [        "-y",        "mcp-cost-optimizer"      ]    }  }}

Status

Core calculations and CLI tested. MCP SDK integration test is provided but could not be executed in the authoring environment because npm registry access is blocked. Run the full validation below before publishing. Package is not yet published to npm. No lockfile is included; generate and commit one after installing in your environment, then use npm ci in CI.

Quick start from source

Requires Node.js 20+.

sh
npm install --ignore-scriptsnpm run checknpm testnode test/mcp.integration.jsnode src/index.js analyze examples/usage.jsonl examples/rates.json demo-budget

The CLI and core have no external dependencies. The MCP server uses the official TypeScript SDK v1 and Zod. No compilation is needed.

Configure your MCP host with an absolute path:

json
{  "mcpServers": {    "cost-optimizer": {      "command": "node",      "args": ["/absolute/path/mcp-cost-optimizer/src/index.js"]    }  }}

Tools

ToolInputResult
estimate_llm_costrecord, ratesSingle-request estimate
analyze_llm_usagerecords, ratesCosts by model, unpriced models, duplicate opportunity
compare_llm_modelsrecords, rates, targetModelIndependent migration scenario

Ask your agent: “Analyze these normalized usage records with my supplied rates. Identify unknown models and repeated requests, then compare a cheaper model. Explain assumptions and do not change production routing.”

Data contract

record: model, inputTokens, outputTokens, optional cachedInputTokens and requestHash. Input includes cached tokens; counts must be nonnegative safe integers. Usage must be normalized before import. OpenAI-style prompt_tokens and Anthropic cache fields are not accepted directly. Do not blindly map Anthropic input counts: sum ordinary input, cache-read and cache-write tokens first; cache-write pricing needs separate treatment and is unsupported in this MVP.

rates: three-letter currency, optional asOf, and models keyed by exact model name. Each model supplies inputPerMillion, outputPerMillion and optional cachedInputPerMillion. All models share the same supplied currency. Missing cache price falls back to normal input price. Real provider prices and currency conversion are deliberately not bundled; example rates are fictional. Unknown model costs are excluded and the report is marked incomplete; comparisons reject incomplete baselines.

requestHash must identify the entire effective request, including tenant, model parameters, system context, tool state and freshness requirements. Repeated hashes identify conditional response caching, not provider prompt caching. The first request is retained. Estimated duplicate savings are an upper bound, assume safe reuse and exclude cache infrastructure cost. Raw prompts are unnecessary. No hash means no duplicate assessment. Use a keyed hash when inputs may be guessable.

Model comparisons keep observed token counts, reset cached tokens to zero and require quality, tokenizer, tool support, latency and context-window evaluation. A more expensive target can return negative savings. Scenarios must not be added together. No invoice reconciliation, taxes or automatic routing.

Privacy and limits

No telemetry, outbound requests, provider credentials or stored usage. MCP tools accept supplied structured data and cannot read files. CLI reads JSON/JSONL under its current directory, resolves symlinks and rejects paths outside that root. Limit: 100,000 records and 20 MiB per CLI file. Files are checked for regular-file type and size before reading, then read in bounded chunks with a second byte limit. JSONL is parsed incrementally and capped at 100,000 records. Descriptor identity is checked at open; this is defense in depth, not a sandbox against concurrent replacement of ancestor directories. Aggregated token counts reject unsafe integer totals, including records with unknown prices. The tool does not automatically observe other MCP/API calls.

Hosted path (quotas via control plane)

Local MCP/CLI stay free and offline. Quotas apply only on a hosted HTTP process that reserves units on mcp-control-plane before analysis.

sh
cp .env.example .env   # set CONTROL_PLANE_URLnpm run start:hosted   # default 127.0.0.1:3102
MethodPathBody
GET/healthLiveness
POST/v1/estimate{ "requestId", "record", "rates" }
POST/v1/analyze{ "requestId", "records", "rates" }
POST/v1/compare{ "requestId", "records", "rates", "targetModel" }

Requires Authorization: Bearer mcp_…. Usage records and rates stay on the hosted host; control-plane sees only product, requestId, and units.

Free and Pro

Local analysis stays free. Hosted Pro quotas use the control-plane path above (history, budgets, alerts remain future).

Roadmap

Provider adapters (including cache-write and reasoning token accounting), verified versioned pricing, project budgets, quality-gated model evaluation, hosted reporting. Validate these with real usage before adding automatic optimizations.

Source: README.md at commit 0f34c62

Tools

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Version history

1
  1. v0.1.1LatestOct 9, 2026