# Common Issues

## Connection issues

<details>

<summary>My API key is rejected or returns an authentication error</summary>

Double-check that you've copied the full API key from the [CoinGecko Developer Dashboard](https://www.coingecko.com/en/developers/dashboard) without any trailing spaces or line breaks. API keys are case-sensitive. If the key was recently generated, wait a minute and try again — new keys can take a short time to activate.

</details>

<details>

<summary>The data flow fails to connect but my API key looks correct</summary>

Verify that your CoinGecko API key is active and hasn't been revoked. Log into the CoinGecko Developer Dashboard and confirm the key status. If you're on a free plan, ensure you haven't exceeded your monthly call limit.

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## Missing data

<details>

<summary>No data is returned for my coin</summary>

The most common cause is an incorrect Coin ID. CoinGecko uses its own internal identifiers — for example, `bitcoin` not `BTC`. Use the [CoinGecko coins list](https://api.coingecko.com/api/v3/coins/list) to find the exact ID for your coin and update your source configuration.

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<details>

<summary>Historical data is empty or incomplete for some dates</summary>

For the Histories entity, check that your start date and end date are set correctly using the date pickers — and that the date range doesn't extend before the coin's launch date. CoinGecko may not have data for very new coins or for dates before a coin was listed.

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<details>

<summary>Community or developer data fields are null</summary>

This is expected behavior for many coins. CoinGecko only populates community and developer data for coins with active social or development activity. Smaller or less-tracked coins will return null for these fields.

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## Data discrepancies

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<summary>Prices in my data don't match what I see on CoinGecko's website</summary>

CoinGecko's website shows real-time prices, while the data in your Coupler.io data flow reflects the moment the data was last fetched. If your data flow runs on a schedule, there will be a natural lag. For Market charts, also confirm that the `days` parameter and currency match what you're comparing against on the site.

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<details>

<summary>Market chart data has fewer data points than expected</summary>

CoinGecko automatically adjusts data granularity based on the `days` value. For 1 day, you get hourly points. For ranges above 90 days, you get daily points. This is a CoinGecko API behavior and cannot be overridden.

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## Rate limits

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<summary>My data flow fails intermittently or returns rate limit errors</summary>

CoinGecko enforces rate limits based on your API plan. Free-tier keys have lower call limits and may be throttled if multiple data flows run at the same time. Consider staggering the schedules of your data flows or upgrading to a paid CoinGecko API plan for higher limits.

{% hint style="warning" %}
Running many simultaneous data flows — especially with the `max` days setting — can quickly consume your API quota. Monitor your CoinGecko dashboard for usage.
{% endhint %}

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