# CurrencyCore FAQ > Answers about getting started, API keys, plans, currency and history coverage, rate limits, MCP, the AI endpoint, migration, and key security. Canonical: https://currency-core.com/docs/guides/faq/ Updated: 2026-11-11 Published: 2026-11-11 --- ## Start ### What is CurrencyCore? CurrencyCore is an API for currency conversion, exchange-rate snapshots, historical series, purchasing-power-parity data, and FX analytics. It also runs a hosted MCP server and an AI endpoint that answer currency questions from the same data. Start with [Getting started](/docs/getting-started/) or the [API reference](/docs/api/). ### How do I make my first request? Create an account, create an organization, create an API key, and send it in the `Authorization` header. The first call can be as small as: ```bash curl "https://api.currency-core.com/v1/convert?from=USD&to=EUR&amount=100" \ -H "Authorization: Bearer cc_test_your_key" ``` See [Getting started](/docs/getting-started/) for JavaScript, Python, Go, Java, and PHP examples. ### Do I need a credit card to start? No. The Free plan includes 1,000 requests per month, 100 AI credits, 3 seats, and the last 30 days of history. No card is required. See [Pricing](/pricing/) and [Rate limits](/docs/rate-limits/). ## Keys ### How do I authenticate a request? Send `Authorization: Bearer ` or `x-api-key: `. There is no query-string authentication. Keys in URLs end up in logs and browser history. See [Authentication](/docs/authentication/). ### What is the difference between a live key and a test key? Live keys use the `cc_live_` prefix, require a paid plan, and use the organization's live quota and rate limit. Test keys use `cc_test_`, work on every plan, return the same reference data, count against the same monthly quota, and are always capped at 60 requests per minute. See [Authentication](/docs/authentication/). ### How do I rotate or revoke a key? Create a replacement key in the dashboard, deploy it, verify traffic, then revoke the old key. You can also disable a key without deleting it. See [Authentication](/docs/authentication/) for the current key controls. ## Plans ### What are the Free plan limits? Free includes **1,000 API requests per month**, **60 requests per minute**, **100 AI credits per month**, **3 seats**, and the **last 30 days** of history. Only successful 2xx requests count toward the monthly quota. See [Rate limits](/docs/rate-limits/). ### Which plan do I need for analytics? The analytics endpoints require **Growth** or higher. That covers `/v1/history/analysis`, `/v1/volatility`, `/v1/correlation`, `/v1/drawdown`, `/v1/safe-haven`, `/v1/mean-reversion`, and `/v1/ppp/analysis`. See [History analysis](/docs/history-analysis-endpoint/) and [Pricing](/pricing/). ### What is the entry paid plan? Starter is **$9/mo** and includes **50,000 requests per month**, full history, live keys, 10 seats, and a 120 requests per minute limit. Public pricing was checked on 2026-11-10. See [Pricing](/pricing/) and [Rate limits](/docs/rate-limits/). ## Data ### How many currencies does CurrencyCore support? CurrencyCore quotes **160 fiat currencies**. `GET /v1/currencies` returns **165 entries**: the 160 fiat codes plus `XAU`, `XAG`, `XPT`, `XPD`, and `XDR` as reference entries. The rate feed is fiat only. See [Currencies](/docs/currencies/). ### How far back does history go? Coverage depends on the pair. GBP/USD and USD/INR include annual parity data from **1949**, daily major pairs start in **1971**, and EUR pairs start in **1999**. Free is limited to the last 30 days; Starter and above get full history. See [History](/docs/history-endpoint/) and [History coverage](/docs/guides/history-coverage/). ### How often do rates update? CurrencyCore uses central-bank reference rates, polled **hourly**, with daily fixings underneath. It is not a real-time or 60-second executable quote feed. Requests use UTC calendar dates. See [Rates](/docs/rates-endpoint/). ### Do you support precious metals or cryptocurrency? No quoted metals or crypto. `XAU`, `XAG`, `XPT`, and `XPD` appear in `/v1/currencies` as reference entries, but the rate feed is fiat only. If your product needs metals or crypto, keep a dedicated provider. See [Currencies](/docs/currencies/). ## Limits ### What counts toward the monthly quota? Only HTTP **2xx** responses count toward the monthly API quota. Client errors (`400`, `401`, `402`, `403`, `404`, `413`, `422`) and server errors (`5xx`) do not. The per-minute limit is different: it counts every request, including errors and retries. See [Rate limits](/docs/rate-limits/). ### What happens when I hit a rate limit? The API returns `429 rate_limited`. A per-minute limit includes a `Retry-After` header. A monthly quota `429` does not reset until the next billing period. See [Errors](/docs/errors/) and [Rate limits](/docs/rate-limits/). ## MCP ### What is the MCP server? CurrencyCore runs a hosted Model Context Protocol server at `https://mcp.currency-core.com/mcp`. It exposes currency, history, PPP, and analytics tools to MCP clients such as Claude, Cursor, VS Code, and ChatGPT. See [MCP server](/docs/mcp/) and [MCP tools](/docs/mcp-tools/). ### How does MCP authentication work? MCP uses OAuth, not an API key pasted into a config file. You add the server URL, sign in through the browser, and choose an organization. The connection is bound to that organization and revalidated on each request. See [MCP OAuth and access](/docs/mcp-oauth/) and [MCP troubleshooting](/docs/mcp-troubleshooting/). ## AI ### What is the AI endpoint and how is it billed? `GET /v1/ai?q=...` accepts a natural-language currency question and returns a structured answer with the data behind it. Native answers cost **1 AI credit**, not an API request. The Free plan includes 100 AI credits per month. See [AI endpoint](/docs/ai-endpoint/) and [AI credits](/docs/ai-credits/). ## Migration ### How do I migrate from another currency API? Inventory your calls, replace query-string auth with a bearer header, diff your stored currency codes against `/v1/currencies`, and map the response envelope. Use the [provider-neutral migration guide](/docs/guides/migration/), then the specific guide for [Fixer](/docs/guides/migrate-fixer/), [CurrencyLayer](/docs/guides/migrate-currencylayer/), or [ExchangeRate-API](/docs/guides/migrate-exchangerate-api/). ## Security ### How should I handle API keys, and where do I report a security issue? Keep keys in a secret manager, send them only in headers over HTTPS, and never put them in query strings, client-side code, or logs. Revoke a key immediately if it is exposed, then create a replacement. Report a suspected vulnerability to [support@currency-core.com](mailto:support@currency-core.com) with "security" in the subject. See [Authentication](/docs/authentication/) and [Support](/docs/guides/support/). ## Related - [OpenAPI specification](/docs/openapi/) - [Authentication](/docs/authentication/) - [Errors](/docs/errors/) - [Rate limits](/docs/rate-limits/) - [All integration guides](/docs/guides/) - [API reference](/docs/api/) - [Support](/docs/guides/support/)