Funding rates and prices as JSON. No key, no sign-up

What this page is

A funding rate is the payment that changes hands between the two sides of a perpetual futures position, on a clock each exchange sets for itself. This site reads those rates, and the prices next to them, from each exchange's own public API about once a minute. The same observations are served as JSON, at the addresses below.

No key, no sign-up, nothing to install. One line is enough to see the whole list:

curl -s https://www.carryroom.com/api/v1/latest

Every response says which release it belongs to, when it was generated, and what it does not contain. Nothing is returned as an empty list to stand in for something that has not been built.

What comes back today

The history of the rates themselves is the next release. Until it is there, the address for it answers with a short note saying so — never with an empty list, which a program cannot tell apart from "nothing matched today".

A kind marked "open" is what this release is willing to return; whether its address is already standing is a separate question, and the list below answers it.

Addresses

No address on this list takes a key, because this release has no notion of one. An address marked "not yet" answers with a short note saying so, and says what to call instead; it never answers with an empty list.

Fetch the list once, then work on it locally. One exchange, its rates and the interval each of them settles on:

curl -s https://www.carryroom.com/api/v1/latest \
  | jq '[.rows[] | select(.venue == "hyperliquid")
         | {symbol, funding_rate_8h, funding_interval_h}]'

The symbol field is the exchange's own spelling, so 1000BONK and BONK are the same asset written twice. Each row also carries the normalised asset name, and that is the one to join on for a cross-exchange comparison. Without a query the list comes back in the same scope the screens use; name the others to widen it, as in ?venues=dydx,btcc. A name that cannot be read is reported back rather than quietly widening the result.

Calling it from an agent

What an agent needs starts from one file, served from this site itself, so there is no package registry in the way. It is the plain skill format that Claude Code, Codex (ChatGPT) and other agents read: a short front matter naming the file, then the rules of the road.

mkdir -p ~/.claude/skills/carryroom
curl -fsSL https://www.carryroom.com/skills/carryroom/SKILL.md \
  -o ~/.claude/skills/carryroom/SKILL.md

That path is Claude Code's. The other agents keep theirs elsewhere:

Codex CLI and Gemini CLI both also read ~/.agents/skills, so one directory serves them together. Start a new session after putting the file in place.

• /skills/carryroom/SKILL.md
• /skills/carryroom.json

Where an agent keeps its skills moves between versions. If yours does not find the file, hand it the address instead. The second address above is the manifest: it lists every file the site is serving, how large each one is, and a digest of what is being served, so an agent can tell whether the copy it holds is still current.

There is no MCP server in this release. The addresses are ordinary HTTP with no key, so an MCP server that can fetch a URL reaches them as they are, and so does an agent's own fetch tool.

What comes back is an observation, not advice. Ask the agent to report the field, its value and its unit as they stand, and to say what the response says it is missing.

Units and times

Each response carries a meta.units block naming the unit of every number in it, so the unit never lives in a document that can drift away from the data. Field names ending in _ms are epoch milliseconds in UTC; field names ending in _utc are RFC 3339.

The four fields that are read wrongly most often:

• funding_rate_8h — a fraction of the position's size per 8 hours. 0.0001 is one hundredth of a percent, not one percent.
• funding_rate_annualised_pct — percent per year, simple: the 8-hour figure times 3 times 365. Nothing is compounded.
• funding_interval_h — the hours between settlements the exchange itself quotes, left exactly as it quotes it.
• mark_price_scaled — the price in the contract's own units. Divide by contract_scale for the price of one coin.

How settlement intervals are handled

Exchanges settle funding on different clocks — the funding settlement interval is one hour on some, four on others, eight on others again. A headline rate from one exchange and a headline rate from another are therefore not the same measurement, and lining them up side by side without saying so is the single mistake this data is most often used to make.

The size of that mistake: a rate of 0.00002 quoted by an exchange that settles every hour is 0.00016 over eight hours, while the same 0.00002 quoted by an exchange that settles every eight hours is 0.00002. Eight times apart, and the larger printed number belongs to the smaller payment.

So both numbers come back, and they are kept apart. funding_rate_8h has already been converted to a per-8-hour basis, which is what makes two exchanges comparable — converting it a second time is the same error twice. funding_interval_h is the exchange's own interval, untouched, so the conversion can be undone or checked.

The interval belongs to the symbol, not to the exchange: one exchange can carry hourly, four-hourly and eight-hourly symbols at the same moment, and a symbol can change its own interval from one day to the next. Rather than print a count here that would quietly go out of date, here is how to count it yourself, right now:

curl -s https://www.carryroom.com/api/v1/latest \
  | jq -r '.rows[].funding_interval_h' | sort -n | uniq -c

The annualised figure is simple, not compounded, and it is a hypothetical: this instant's rate extended to a year, not a forecast and not a realised return. The arithmetic is set out under how to read the numbers.

Where exchanges differ from one another

Three differences survive every attempt to flatten them, so the response keeps them visible rather than picking one convention and hiding the rest.

• Some exchanges price the two sides of the trade independently. Those rows say carry_model is directional, have no funding_rate_8h at all, and carry funding_return_8h_short and funding_return_8h_long instead. Flipping the sign of one to get the other does not work: both sides can be negative at the same time, and folding them into a single number invents a trade that does not exist.
• One contract is not always one coin. contract_scale says how many coins one contract stands for, baked into the exchange's own symbol — 1000PEPE is 1000. Divide the price by it before comparing prices across exchanges. The rate is a fraction of what you hold, so the scale does not touch the rate.
• Not everything on the list is perpetual. Where expires_at_ms is not null the contract has a settlement date, and dated contracts have no funding mechanism at all: their funding_rate_8h is exactly 0.0, which is not a quiet market but the absence of the mechanism. Sort by funding and they sort last. What they carry sits in the gap between the dated price and the perpetual price on the same exchange.

How much is covered

Exchanges listed on this site: 48. Funding rates and prices are read from those, about once a minute.

How many of them actually appear in a given response is a different number, and the response counts it rather than claiming it: meta.coverage carries the count, and the venues address lists them one by one with whether each is in the current observation.

curl -s https://www.carryroom.com/api/v1/venues

Coverage is not one number for the whole site: it differs by the kind of number asked for. This release returns funding rates and prices, and does not return order-book depth, turnover or the history of the rates — so it publishes no count for those, because it has not measured them here.

How many calls

Ask for the list in one call rather than one call per symbol. What is measured is the shape of the traffic as well as the count: many different symbols fetched once each looks like a sweep, while a few of them watched repeatedly does not.

A refusal comes back as 429 with Retry-After and the address to call instead, so a program can recover without a person reading a document.

Cost

There is no charge for any of this, and there is nothing to buy on this site. No price is quoted anywhere, and no payment is taken.

Questions we are asked