Twenty-eight financial tools this month — data feeds, backtesting engines, broker SDKs, ledgers, on-chain indexers and the money software worth actually running, split between the defaults people already reach for and things that shipped in the last few months.
In October 2025, Polygon.io renamed itself Massive and kept the same stock, options, forex, crypto and (now) futures feeds running underneath. This September it added a pay-per-request mode that settles in USDC over Base, no API key required, alongside the standard REST and WebSocket access. pip install polygon-api-client still points at the same endpoints if you don't need that new path. Pricing: the free Basic tier caps at 5 calls a minute, end-of-day data only, 2 years of history; paid plans start at $29/month for unlimited calls with a 15-minute delay and reach $199/month for real-time data.
Stocks, forex, crypto, technical indicators and macro series all sit behind one Alpha Vantage API key, and an official MCP server now exposes more than 100 of those endpoints as callable tools instead of hand-written requests. Register for a free key at alphavantage.co, or point an MCP client at the server repo if you'd rather let an agent make the calls. Pricing: the free tier caps at 25 requests a day; paid plans start at $49.99/month for 75 requests per minute.
FRED still holds 800,000-plus economic series from the St. Louis Fed: GDP, CPI, unemployment, rates, going back decades. Register for a free key and query the REST endpoint directly, or work through the fredapi Python wrapper. Pricing: free, with no published rate limit in the documentation.
LEAN runs the identical strategy code in backtest and live trading across equities, options, futures, forex and crypto, in either C# or Python. pip install lean gets the CLI, or clone the repo and run the whole engine locally with Docker instead of QuantConnect's hosted cloud. Pricing: free and open source under Apache-2.0; the hosted QuantConnect Cloud platform layers its own paid tiers on top.
skfolio brings mean-variance optimization, hierarchical risk parity and HERC clustering into an API shaped like scikit-learn's, so portfolio construction slots into the same pipeline as a classifier would. pip install skfolio and you're fitting an allocation model in a few lines. Version 1.3.4 shipped September 25, 2026, continuing a pace that's barely slowed since the project's 2025 arXiv paper. Pricing: free and open source, BSD-3-Clause.
Jesse's indicator engine, more than 300 of them, now runs through Rust via PyO3 instead of pure Python, a change that landed across its v3 releases this month. pip install jesse or pull the Docker image, then connect it to Kraken Pro or KuCoin for live execution. Five releases shipped between September 12 and 23, 2026 alone. Pricing: free and open source, MIT.
Coinbase's own Python SDK covers spot and derivatives trading on Advanced Trade: order placement, portfolio management, market data, authenticated through the newer CDP keys instead of legacy credentials. pip3 install coinbase-advanced-py and a funded account is placing orders within a few lines. Pricing: the SDK is free; trades run on Coinbase's standard maker and taker fee schedule.
When TD Ameritrade's API retired into the Schwab migration, it left a gap that Schwabdev has been filling with a maintained Python wrapper for quotes, streaming and order placement against the Schwab Trader API. pip install schwabdev, then register a separate app through Schwab's Developer Portal for credentials. Version 4.0.0 shipped August 9, 2026. Pricing: free and open source; trading requires a funded Schwab brokerage account.
This unofficial async SDK for Tastytrade moves faster than the broker's own official client, with typed models for accounts, orders and streaming data built around the options-focused brokerage's API. pip install tastytrade, then authenticate with your Tastytrade account credentials. v13.2.3 went out August 7, 2026. Pricing: free and open source; live use requires a funded Tastytrade account.
Double-entry bookkeeping, invoicing and expense tracking for small businesses run through Akaunting's Laravel app, which you can self-host or rent from the company directly. docker run the self-hosted image, and the Standard plan is free for up to two users, one company and 1,000 invoices a year, converting to GPLv3 four years after each release. Pricing: self-hosted Standard is free (BSL 1.1, later GPLv3); hosted Cloud plans start at $12/month for one company.
Beancount defines transactions in a plain-text language, then compiles the ledger file into balance sheets, income statements and a queryable database rather than a spreadsheet. Write entries in any text editor, run bean-check to validate them, and add the Fava web UI if a browser view is more your speed. The last commit landed August 23, 2026. Pricing: free and open source, GPL-2.0.
CAMT.053, PAIN.001, MT940, OFX, CSV, even scanned PDFs: bankstatementparser turns all of them into one unified transaction model, with balance verification and PII redaction built in, then exports straight into an hledger or Beancount ledger. pip install bankstatementparser, adding the [hybrid] extra for an LLM fallback on messy PDFs. Version 0.0.19 shipped September 1, 2026. Pricing: free and open source, dual Apache-2.0/MIT.
FinGPT fine-tunes open base models with lightweight LoRA adapters for sentiment analysis, forecasting and robo-advising on financial news and social data, rather than training a finance model from scratch. Clone the repo and pip install -r requirements.txt, or grab pretrained checkpoints from Hugging Face. Pricing: free and open source, MIT; you only pay for whatever base-model inference you run it on.
Separate LLM agents handle fundamental, sentiment and technical analysis in TradingAgents, then hand their output to trader and risk-management agents built on LangGraph, with point-in-time data integrity so a backtest can't accidentally see the future. pip install . from a cloned repo and supply a key for whichever model provider runs the agents. Version 0.5.1 shipped this September with SEC EDGAR fundamentals and a reorganized package layout. Pricing: free and open source, Apache-2.0; you pay your model provider for the inference.
European company filings, financials and ISINs come through this MCP server as sixteen tools by default, expandable to 46 for the full FinancialReports API surface. Sign up free at financialreports.eu, then claude mcp add --transport http financialreports https://mcp.financialfilings.com/mcp and authenticate in the browser, no manual key handling required. Pricing: free account and MCP access; whether a paid tier exists at higher usage isn't disclosed on the signup page.
Most US and Canadian fintech apps still link a user's bank account through Plaid: balances, transactions, identity data and ACH details behind one API, with SDKs in Node, Python, Java, Go and Ruby. A free Sandbox key returns realistic fake transaction data in minutes, and a Limited Production tier then allows up to 200 live calls per product for real testing. Pricing: Sandbox and Limited Production are free; pay-as-you-go, Growth and Scale tiers are priced by quote and not published.
Formance Ledger is a programmable core ledger meant to sit as the system of record under a payments or banking product, modeling atomic double-entry transactions through its own Numscript DSL. docker run the compose setup, or install a standalone binary through Homebrew or apt. Commits are landing daily even though the last tagged GitHub release dates back to a 2024 beta. Pricing: free and open source, MIT; Formance also sells a managed cloud tier separately.
Midaz is a cloud-native, multi-currency core ledger from Lerian, paired with companion services for onboarding orchestration, real-time transaction risk and regulatory reporting. git clone the repo, run make set-env and make up, and the Ledger API comes up on port 3002 through Docker. Lerian raised a R$30 million seed round in January 2026 and commits have kept landing daily since. Pricing: free to self-host under the Elastic License 2.0, source-available rather than OSI open source; no separate paid tier is published.
Yente is the self-hostable matching engine behind OpenSanctions' sanctions, PEP and watchlist data, the screening layer under most KYC and AML checks. Run it with docker-compose against your own ElasticSearch index, or call the hosted API after a business-email signup. A July 2026 collaboration with transaction-monitoring vendor Marble produced a faster matching engine plus a new client SDK and MCP server. Pricing: self-hosted Yente is free (MIT); the hosted API runs €0.10 per query after a 30-day trial.
Reth is Paradigm's Rust implementation of the Ethereum execution client, modular enough to run as a full or archive node or embed directly into a Rust application. cargo install reth, or run the official Docker image instead of building from source. Version 2.6.0 shipped September 17, 2026, on a cadence that's landed roughly every one to two weeks all year. Pricing: free and open source.
viem has taken over from ethers.js as the default TypeScript interface for much of the Ethereum ecosystem: typed contract calls, ABI encoding, wallet and RPC clients, EIP-712 signing, with the type inference that made it popular in the first place. npm install viem and a contract call comes with full autocomplete on its ABI. Pricing: free and open source.
rindexer indexes EVM contract events into a Postgres-backed dataset with a GraphQL API on top, configured entirely in YAML unless custom logic calls for dropping into Rust handlers. curl -L https://rindexer.xyz/install.sh | bash, or run the Docker image against a fresh project path. The project only broke out this year, with 887 commits already on the main branch and a push as recent as September 16, 2026. Pricing: free and open source.
Most custody and smart-account products on Ethereum build against Safe{Core}'s Protocol, API and Relay kits: creating and executing multisig transactions, sponsoring gas through ERC-4337 without asking a user to hold ETH. npm install @safe-global/protocol-kit gets the core package, and the Transaction Service behind it is free to call. Pricing: free and open source, MIT.
Dashboards, screeners, charting and macro data from S&P Capital IQ come together in Koyfin's free browser-based terminal, positioned as a Bloomberg alternative with no install required. The free tier caps out at two dashboards, two watchlists and two screens before hitting a paywall. Pricing: free tier available (2 dashboards/watchlists/screens, 2-year financials); Plus is $39/month, Premium $79/month, up to $299/month for Advisor Pro.
FinanceToolkit computes more than 150 financial ratios, valuation metrics and performance measures directly from raw financial statements, showing its formulas instead of hiding them behind a score. pip install financetoolkit -U, then supply a Financial Modeling Prep API key for the underlying statement data. Version 2.2.0 shipped August 18, 2026 on a steady monthly cadence. Pricing: the library is free and open source (MIT); the FMP data behind it carries its own separate free tier.
quantstats turns a plain return series into a full tearsheet: Sharpe ratio, drawdowns, volatility, win rate, rendered as an HTML report instead of a notebook someone has to open and run. pip install quantstats --upgrade, then call quantstats.reports.html() against your returns. Pricing: free and open source, Apache-2.0.
Ghostfolio tracks net worth and portfolio performance, stocks, ETFs, crypto, across every account you connect, with FIRE-oriented benchmarking built into the dashboard. docker pull ghostfolio/ghostfolio and stand it up against Postgres and Redis on your own server. An experimental MCP watchlist tool landed behind an ENABLE_FEATURE_MCP flag in the September 20, 2026 release. Pricing: self-hosting is free (AGPL-3.0); the hosted Ghostfolio Premium cloud plan runs around $48/year.
Firefly III has run self-hosted budgets, bills and bank-import rules for years, and just went through its biggest visual overhaul yet: a full layout redesign in v6.7.0, followed a day later by a switch from Twig to Blade templating. docker run fireflyiii/core:latest gets an instance up, with patch releases landing almost daily through September 2026. Pricing: free and open source, AGPL-3.0.