# min_childkey_take (/docs/hyperparameters/min-childkey-take)

Sets the minimum take a childkey can charge on this subnet. It matters to
validators running parent–child hotkey setups
([`set-children`](/docs/tx/set-children)): the take is the share of
child-earned dividends the childkey keeps before passing the rest back to its
parents. A subnet owner can raise this floor to stop childkeys from
undercutting each other to zero.

## How it works [#how-it-works]

The value is stored per subnet as a `PerU16` fraction (65535 = 100%). The
chain combines it with the global, root-set minimum: the **effective floor is
the greater of the two**, so a subnet can only make the global minimum
stricter, never looser. Both defaults are currently 0.

The floor is enforced in two places. Setting a take via
[`set-childkey-take`](/docs/tx/set-childkey-take) rejects values below the
effective floor (or above the global maximum, 11796/65535 ≈ 18%) with
`InvalidChildkeyTake`. And every read of a childkey's take clamps up to the
floor — so raising it immediately re-prices existing childkeys that were set
lower, without anyone resubmitting.

The setter itself bounds the floor to the \[global min, global max] range, so
an owner cannot set a floor above 18%.

Raise the floor below and watch an existing childkey's take get pushed up:

<HyperparamChildkeyTakeRange />

## Reading and setting [#reading-and-setting]

```bash
btcli sudo get --netuid 12 --name min_childkey_take
btcli sudo set --netuid 12 --name min_childkey_take --value 0.05
```

Settable by the subnet owner or root. The value is a fraction between 0 and 1
written with a decimal point (`0.05` = 5%, stored as 3276/65535). The get
command reports the effective floor — the max of global and per-subnet values.

## Related [#related]

* [`transfers_enabled`](/docs/hyperparameters/transfers-enabled)
* [`owner_cut_enabled`](/docs/hyperparameters/owner-cut-enabled)
* [`set-children`](/docs/tx/set-children) and
  [`set-childkey-take`](/docs/tx/set-childkey-take) — the transactions this
  floor governs