Prediction Market Tools You Run Yourself

What the flag claims, and what it does not

access.self_hosted says the product can run on hardware you control: a library inside your own process, an application you deploy, or the second half of a product whose default path is somebody else's server. Seventeen of the sixty cards here carry it.

It is not the same claim as access.open_source, and the two come apart on five cards in this catalogue. Fifteen of these seventeen are open source as well, which is why this page was held back twice. The other two are the argument for it.

kalshi-python and the current Kalshi Python SDK are the exchange's own generated packages. Both declare LicenseRef-Proprietary, the repository their metadata names returns 404 to anyone outside the company, and there is no issue tracker, no commit history and no patch you can send. Both also run in your process, hold the RSA private key that signs your orders, and send nothing anywhere but Kalshi. Closed code, your machine.

Pointing the other way: Manifold, the Manifold API and Quantified Intuitions publish their source under MIT and are not in this collection. Manifold's code is why its fee position is a fact rather than a promise — the taker fee constant and the flat trade fee in it are both zero — but the questions, the balances, the accounts and the resolutions are on a server you do not run, so there is nothing here to deploy. A licence says what you may do with the code. This flag says where the process runs.

Three different things wear the word

A library in your process. Most of the listing. polymarket-client, pykalshi, limitless-sdk, CCXT, polymarket-us-python, polymarket-us-typescript, py-clob-client and the two Kalshi packages import into your program and hold whatever credential you hand them. "Self-hosted" here means there is no third party in the call path at all — and it also means the dependency list runs in the same process as the key.

An application you deploy. Confido has no public instance to join: the supported route is a Gradle build whose run task serves the compiled front end on port 8080, and the institute's pitch is that the data never leaves your server. Alphapoly is a FastAPI backend plus a front end on localhost. Fatebook ships a docker compose path with its own Postgres and a local mail catcher, and is careful to call it a development environment rather than a supported self-hosted product — a private deployment means bringing your own identity provider. Metaculus is the commercial version of the same requirement: private instances deployed inside an organisation are something the company sells, not something you download.

A pipeline and its data. Prediction Market Analysis is indexers, a 36 GiB Parquet snapshot and an analysis harness; keeping it current means running the collectors yourself. Brier.fyi is the sharpest case in the listing, because self-hosting is the only route to a current number: the site is up, its last commit is dated 24 January 2026, the one before it is titled "infra, pause nightly data pipeline", and its public API answered 502 when the card was written. The scores are frozen and the code that made them is MIT.

And one product is both halves at once. PMXT sells a hosted Data API and also ships pmxt-core, which spawns a local service and talks to the venues directly with your own venue credentials. The documentation's sentence for that mode is that venue credentials stay on your machine. The quickstart's default is the hosted path, with a pmxt_api_key and a private_key in the same constructor — so here self-hosting is a decision, not a property.

What it does not buy you

It does not mean nothing leaves. Alphapoly runs entirely on your machine and still ships market text and prompts to OpenRouter and JSON-RPC calls to your Polygon node provider. Running the process locally narrows who sees your traffic; it does not empty it.

It does not make a key safe. The Polymarket CLI writes a freshly generated private key unencrypted into ~/.config/polymarket/config.json — no passphrase, no keychain, no hardware-wallet path — which on a shared or backed-up machine is a funded account in a file. Where your key lives is the page for that decision, and the open-source collection for what reading the code does and does not tell you about it.

It does not open an account. Alphapoly installs anywhere and trades on the on-chain Polymarket, which does not serve US persons. The Kalshi packages install anywhere and are useless without a key from a funded Kalshi account. The flags on a client card describe the client; why a venue is unavailable where you are is where the actual gate is described.

And one licence reaches further than people expect. Confido is AGPL-3.0, which covers a modified version offered to others over a network — which is exactly what a self-hosted forecasting workspace inside a company is.

Nothing in this collection has been deployed by this site against a funded account. Build steps, licences, credential handling and dataset sizes above are read from each vendor's own documentation and repositories, and dated on the cards.