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Next: the five parts of a bot
A library only handles the connection. The Python trading bot page shows the parts it does not.
What is included
- What it is, in plain words
- The formula or mechanism, with exact arithmetic
- How it hits grid, martingale and DCA bots
- A check you can run before you switch a bot on
Who it is for
- People who run or plan to run a trading bot
- Anyone reading a backtest or a bot sales page
- Readers who want the numbers, not the pitch
- Not advice, and not a signal service
Key facts
- CCXT is an open source code library that puts one common set of commands in front of the separate APIs of many crypto exchanges. It is available for more than one programming language. Check its current documentation for which.
- The idea: write the bot once, change the venue name, and the library translates. The reality: each venue still has its own rules, steps, limits and quirks, and the bot has to handle them.
- A library does not make an exchange safe, fast or reliable. Your keys, your sizes and your error handling are still yours.
- The same intended order of 0.0456 keeps 98.7 percent of its size at a made-up venue with a step of 0.001 and 87.7 percent at one with a step of 0.01 (calculated by us on 31 Oct 2026, exact).
- This page explains how something works and does not recommend it. We have not tested it for this page. Check the current terms.
What CCXT is
Every exchange publishes its own API, and no two are quite alike. The names of the fields differ, the way a market is written differs, and the errors differ. A programmer who wants a bot to work on more than one exchange would otherwise have to learn and code each one. CCXT is an open source library that does that work: it offers a common set of commands, such as load the list of markets, fetch a price, fetch a balance and create an order, and inside it turns each command into the request a particular exchange wants.
We have not installed it or read its current documentation for this page. Which exchanges it covers, which commands it has, how it handles each venue and how often it is updated are things to read there, not here.
What a common interface does for you
- Less code per venue. One way to ask for a price or send an order, for each exchange it supports.
- Easier comparison. The same bot can read prices from several venues in a common format, which helps when you study differences between them.
- A way to move. If a venue closes or changes, you may not have to rewrite the whole bot.
- A shared place to look. Many people use the same library, so questions and bug reports are public.
What it cannot hide
- Different steps and minimums. Each market has its own quantity step, price step and minimum order value. The library can tell you them, and your bot still has to round to them.
- Different order types. A common command may not exist for a special type on one venue, or may behave a little differently.
- Different limits. Each venue limits how fast you can send requests. Writing one loop for three venues can break the limit on one of them.
- Different fees. The fee model is the venue's, and varies by account.
- Library lag. If a venue changes, the library has to be updated before your bot is right again.
Worked example: one order, three venues
Suppose a bot wants to buy 0.0456 of an asset priced at 100 on three made-up venues. Venue A has a quantity step of 0.001, Venue B a step of 0.01 and Venue C a step of 0.0001. Each has a made-up minimum order value, written below. The bot rounds the quantity down to the step, then checks the value against the minimum.
| Venue | Quantity step | Rounded quantity | Order value at 100 | Minimum value | Result | Share of intended size kept |
|---|---|---|---|---|---|---|
| Venue A | 0.001 | 0.045 | 4.50 | 5 | rejected | 98.7% |
| Venue B | 0.01 | 0.04 | 4.00 | 5 | rejected | 87.7% |
| Venue C | 0.0001 | 0.0456 | 4.56 | 10 | rejected | 100.0% |
Calculated by us on 31 Oct 2026, exact for the made-up rules. One command and one intended size gave three different orders, and one of them is under the made-up minimum. The library can read the market information and give you the steps. It does not decide what your bot should do when the order is too small: skip it, raise it, or stop. That is bot logic, and it needs a test for each venue you use.
Worked example: counting requests
A made-up bot checks the price and the balance once a minute for each market on each venue. That is two requests a minute, or 2,880 a day, per market per venue. The figure shows what that grows to: 1 markets on 1 venue is 2880, 3 markets on 1 venue is 8640, 3 markets on 3 venues is 25920, 10 markets on 3 venues is 86400 requests a day. Each venue sets its own limit, so read the current page for each one before widening a loop.
How a bot using a common library breaks
- Assuming sameness. A bot tested on one venue is trusted on another without a separate test.
- Hidden defaults. The library may fill in a value you did not set. Read what it sends, and log it.
- Update surprises. A new library version can change a name or a behaviour. Pin the version you tested, and test again before moving.
- Key handling. The library needs your key and secret. Use the same rules as for any API: small permissions, no withdrawals, secrets out of code. See Binance API.
How to check it
- Test each venue separately on its practice environment if there is one, then on small real size.
- Print the exact request that goes out for one order on each venue.
- Round to each market's steps, and test the minimum value case.
- Count requests per day per venue and compare with that venue's current limit.
- Write down the library version you tested.
What this page does not tell you
It does not list supported exchanges, commands or languages, and it does not say how well any of it works. The venues and numbers here are made up. For building a bot around such a library see Python trading bot and open source crypto trading bot.
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FAQ
Frequently Asked Questions
What is CCXT?
It is an open source library that gives a program one common set of commands for many crypto exchange APIs. Read its current documentation for the exchanges and languages it supports.
Does CCXT make a bot safe?
No. Safety depends on your key permissions, your sizes, your error handling and testing. The library only translates requests.
Do I still need to read each exchange's documentation?
Yes. Steps, minimums, limits, fees and order types are the venue's, and the library cannot make them the same.
Why did the same code behave differently on two exchanges?
Each market has its own rounding steps, minimum order values and rules. Test every venue separately.
Can a library cause my bot to break?
It can when a venue or the library changes. Pin the version you tested and test again before updating.
Are the numbers on this page real?
Example numbers are made up to show how the maths works, and the page says so. A figure only counts as exact when the page says it was calculated on a stated date. Nothing you enter in a calculator leaves your browser.
Can I use this to decide whether to run a bot?
It can show whether a bot's numbers hold together and how much an account can lose. It cannot say what the market will do, and it is not advice. Use it to ask better questions, then read the terms of your own broker or exchange.
Is this financial advice?
No. It explains what a common exchange library is and does not recommend any tool or venue.
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