> For the complete documentation index, see [llms.txt](https://docs.nexus.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nexus.xyz/api-reference/markets/fetch-mark-price.md). # GET /markets/{market\_id}/mark-price Get mark price Get mark price. `operationId`: `fetchMarkPrice` > **Declared server:** `https://api.testnet.nexus.xyz/v1`. See [Networks](/api-reference/guides/networks.md). > **Not reachable through CCXT.** CCXT models mark price as a FIELD, `Ticker.markPrice`, which our `Ticker` schema already declares: `GET /markets/{market_id}/ticker` is badged fetchTicker and `GET /tickers` fetchTickers, so the datum is already reachable through CCXT's own vocabulary. In ccxt 4.5.76 fetchMarkPrices returns Ticker structures keyed by symbol and fetchMarkPrice derives the single-symbol case from it, so badging this route would promise a Ticker from a response that carries one scalar and a market id. Reachable natively as the implicit publicGetMarketsMarketIdMarkPrice. **Authentication:** none. This endpoint is public. ## GET /markets/{market\_id}/mark-price > Get mark price ```json {"openapi":"3.1.0","info":{"title":"Nexus Exchange API","version":"0.9.101"},"tags":[{"name":"Markets","description":"Market parameters and summaries"}],"servers":[{"url":"https://api.testnet.nexus.xyz/v1","description":"Public testnet (play funds) — the default server and /v1 transport base for unversioned paths."},{"url":"https://api.nexus.xyz/v1","description":"Mainnet — **REAL FUNDS**. Collateral is USDX bridged from Ethereum Mainnet; orders placed here move real money, and there is no faucet. The durable per-network base. Listed after testnet on purpose, so nothing that reaches for \"the first https server\" lands on the real-funds target. Not resolvable yet: DNS/TLS is a separate infra change."},{"url":"http://localhost:9090","description":"Local development — the indexer served directly. Not a public network; whatever your local instance holds."}],"security":[],"paths":{"/markets/{market_id}/mark-price":{"get":{"operationId":"fetchMarkPrice","tags":["Markets"],"summary":"Get mark price","parameters":[{"$ref":"#/components/parameters/MarketId"}],"responses":{"200":{"description":"Current mark price for the market.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/MarkPriceResponse"}}}},"400":{"$ref":"#/components/responses/InvalidMarketId"},"429":{"$ref":"#/components/responses/RateLimited"}}}}},"components":{"parameters":{"MarketId":{"name":"market_id","in":"path","required":true,"schema":{"type":"string","pattern":"^[A-Z0-9]+(-[A-Z0-9]+)*$","maxLength":64},"description":"Market identifier (e.g. BTC-USDX-PERP, ETH-USDX-PERP). Uppercase ASCII alphanumeric segments joined by single hyphens, at most 64 characters. A value outside that set is rejected with `400` (`INVALID_MARKET_ID`) before any store is read — it cannot name a market, so an empty result would assert that nothing traded rather than that the question was malformed. A well-formed identifier that names no listed market is a `404`, not a `400`."}},"schemas":{"MarkPriceResponse":{"type":"object","description":"The current mark price for one market. `/markets/{market_id}/mark-price` and its `/api/v1` twin are the same handler behind two mounts, so the two responses cannot diverge.","required":["market_id","mark_price"],"properties":{"market_id":{"type":"string","description":"The market the price is for, echoed from the path."},"mark_price":{"allOf":[{"$ref":"#/components/schemas/Decimal"}],"description":"Mark price as a decimal string at the market's own scale — trailing zeros are significant and preserved (`\"50011.60\"`, not `\"50011.6\"`). Never a zero or a null: an absent or stale mark is signalled by the response status, not by a sentinel in this field."}}},"Decimal":{"type":"string","description":"Arbitrary-precision decimal serialized as a string (lossless). Parse with a decimal type, never a float."},"RateLimitError":{"type":"object","description":"The body of a 429. Branch on `code` (always `RATE_LIMIT_EXCEEDED`) and on `bucket` to learn WHICH budget bottlenecked. Schematised rather than left to `examples` because `bucket` is meant to be read by machines: an example gives a generated client no field and a validator nothing to check `\"bucket\": \"ownr\"` against. `bucket` here and the `X-RateLimit-Bucket` header carry the same value and the same enum.","required":["code","message","bucket"],"properties":{"code":{"type":"string","enum":["RATE_LIMIT_EXCEEDED"],"description":"Always `RATE_LIMIT_EXCEEDED` on this response. The other 429s this API can return carry different codes (`too_many_agents`, `rate_limited`, `cap_exceeded`, `daily_limit_exceeded`) and are not this shape."},"message":{"type":"string","description":"A diagnostic whose wording is NOT stable. Do not parse it; branch on `bucket`."},"bucket":{"type":"string","enum":["key","owner","order","cancel","ip","login"],"description":"Which budget refused this request. `key` — the per-API-key bucket; `owner` — the per-account request bucket; `order` — the trading-action bucket, order submission and amend only; `cancel` — the separate cancellation bucket, `DELETE` on the order surface only; `ip` — the public per-IP bucket for unauthenticated and gateway traffic; `login` — the dedicated per-IP bucket for `POST /auth/login`, tighter than `ip` and drawn from its own pool, so a login refusal leaves the read budget untouched and vice versa. The buckets are independent, so a caller at its read ceiling can still submit orders, and a caller at its submission ceiling can still cancel — do not back off the whole client on any one of them."},"tier":{"type":"string","description":"The rate-limit tier the refused request was charged against — `public` for the per-IP bucket, otherwise the authenticated key's tier. Absent on responses from paths that refuse before a tier is resolved."}}}},"responses":{"InvalidMarketId":{"description":"The supplied `market_id` path or query value is not a well-formed market identifier: it must match `^[A-Z0-9]+(-[A-Z0-9]+)*$` and be at most 64 characters. Branch on the body's `code`, which is always `INVALID_MARKET_ID`; `message` restates the rule and is a diagnostic whose wording is not stable. The result for a well-formed identifier that is not currently available is operation-specific and documented by that operation.","content":{"application/json":{}}},"RateLimited":{"description":"Rate limit exceeded. **Retryable** — honour `retry-after` and back off; this is what separates a `429` from the permanent `403` jurisdiction refusals. Branch on the body's `code`, which is always `RATE_LIMIT_EXCEEDED`, and on `bucket` to learn WHICH budget bottlenecked — the buckets are independent, so a caller at its read ceiling can still submit orders and should not back off the whole client. Do not parse `message`: it is a diagnostic whose wording is not stable. Requests are charged by weight, so exhausting a budget takes fewer heavy calls than `x-ratelimit-limit` suggests. See “Rate limits” in the API description.","headers":{"X-RateLimit-Limit":{"schema":{"type":"integer"},"description":"Budget of request weight per second for your tier — not a count of requests. Sent on successful responses too."},"X-RateLimit-Remaining":{"schema":{"type":"integer"},"description":"Tokens left, in unit-cost requests: 10 means ten weight-1 requests or two weighing 5. Sent on successful responses too. Always `0` on this response."},"X-RateLimit-Reset":{"schema":{"type":"integer"},"description":"Unix timestamp (seconds) when the budget is whole again. Sent only on a `429`, never on a success."},"Retry-After":{"schema":{"type":"integer"},"description":"Seconds to wait before retrying, never below 1. Derived from the **weighted** cost of the refused request, so it is not in the same unit as `X-RateLimit-Remaining`. Sent only on a `429`."},"X-RateLimit-Bucket":{"schema":{"type":"string","enum":["key","owner","order","cancel","ip","login"]},"description":"Which budget refused this request, mirroring the body's `bucket`. `key` — the per-API-key bucket; `owner` — the per-account request bucket; `order` — the trading-action bucket, order submission and amend only; `cancel` — the separate cancellation bucket, `DELETE` on the order surface only; `ip` — the public per-IP bucket for unauthenticated and gateway traffic; `login` — the dedicated per-IP bucket for `POST /auth/login`, tighter than `ip` and drawn from its own pool, so a login refusal leaves the read budget untouched and vice versa. The read, trading and cancellation budgets are counted separately, so a `429` on one does not mean the others are exhausted — in particular a `429` naming `order` never means your cancels are refused. Sent only on a `429`."}},"content":{"application/json":{"schema":{"$ref":"#/components/schemas/RateLimitError"}}}}}}} ``` *** API version `0.9.131` --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.nexus.xyz/api-reference/markets/fetch-mark-price.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. 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