# HTTP Outcalls and needed cycles

**URL:** <https://forum.dfinity.org/t/http-outcalls-and-needed-cycles/33261>\
**Category:** Developers\
**Created:** [July 16, 2024, 5:40am UTC](https://forum.dfinity.org/t/http-outcalls-and-needed-cycles/33261 "2024-07-16T05:40:29Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![rbole](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/rbole/32/1334_2.png) [@rbole](https://forum.dfinity.org/u/rbole)\
**Post date:** [July 16, 2024, 5:40am UTC](https://forum.dfinity.org/t/http-outcalls-and-needed-cycles/33261/1 "2024-07-16T05:40:29Z")

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GM,  
if I do a http outcall I have to add some cycles:

```auto
Cycles.add<system>(addAmountOfCycles);

```

In the docs there is an amount of 230\_949\_972\_000 cycles proposed.

What happens if the call does not require all the cycles? Are they lost or are only the required portion of the cycles used?

Thanks for the clarification.

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<div class="post-metadata">

**Author:** ![Vivienne](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/vivienne/32/29170_2.png) [@Vivienne](https://forum.dfinity.org/u/Vivienne)\
**Post date:** [July 16, 2024, 8:34am UTC](https://forum.dfinity.org/t/http-outcalls-and-needed-cycles/33261/2 "2024-07-16T08:34:11Z")

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The system refunds the extra cycles. If your canister has enough balance just send it off with a bunch of cycles and don’t think about it. That’s what I do in a lot of my own canisters

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<div class="post-metadata">

**Author:** ![rbole](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/rbole/32/1334_2.png) [@rbole](https://forum.dfinity.org/u/rbole)\
**Post date:** [July 16, 2024, 8:55am UTC](https://forum.dfinity.org/t/http-outcalls-and-needed-cycles/33261/3 "2024-07-16T08:55:55Z")

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Thanks that makes it lot easier.