Registration and UID slots

Registration is the one step in mining that costs real money before you have earned anything. It is worth understanding precisely what you are buying.

UID slots are finite

Every subnet has a fixed number of UID slots, set by the max_allowed_uids hyperparameter. The chain default is 256 and owners may trim it, but not below 64. Registering a hotkey claims one of those slots.

If the subnet has free slots, your registration simply fills one. If the subnet is full, your registration evicts an existing neuron — the one with the lowest pruning score that is not currently immune. Someone loses their UID so that you can have it.

A full subnet is a harder entry

Registering into a full subnet means you arrive at the bottom of the ranking in a field where every occupant has already proven they can outscore a newcomer. TaoScope shows free slots and slot utilisation on every subnet page so you can see this before committing.

The registration cost

Registration on a dTAO subnet is done by burning TAO — the burned-register path. The TAO is recycled into the protocol's issuable supply rather than paid to anyone, which is why TaoScope labels it “recycled”.

The price is dynamic, not fixed:

  • Each successful registration raises the burn price for the next one.
  • The price decays back down over time when nobody registers.
  • Popular subnets therefore stay expensive; quiet ones drift cheaper.

This means the cost you see can change between checking and submitting. Always confirm the live figure immediately before registering:

Check the current burn before you commit
btcli subnets show --netuid <NETUID>

TaoScope records the registration cost it observes for each subnet over time and charts it on the subnet detail page, so you can see whether the current price is high or low relative to recent history.

The burn is not refundable

If you register and are deregistered an hour later, the TAO is gone. It is not a deposit and there is no mechanism to reclaim it.

The immunity period

A newly registered neuron is protected from eviction for a number of blocks defined by the subnet's immunity_period. While immune, you cannot be pruned no matter how low your score is.

The chain default is 4,096 blocks, about 13.7 hours at 12-second blocks — but real subnets frequently set it much higher. Read the live value rather than assuming the default; TaoScope displays it in blocks and in hours on each subnet page.

Immunity is your runway

The immunity period is the time you have to get your miner producing scoreable output before you become evictable. If a subnet gives you 13 hours, your setup needs to work on the first attempt. Test everything on the test network first.

Deregistration

When a full subnet receives a new registration, the chain selects a victim by pruning score, which is based on emissions. The lowest-scoring non-immune neuron loses its UID. Where scores tie, the older registration is removed first.

Deregistration is mechanical rather than a judgement, and its consequences are narrower than people often assume:

What happensWhat does not happen
You lose the UID slot on that subnet.Your stake is not confiscated; it stays where it is.
You stop earning emission from that subnet.Your hotkey and coldkey are unaffected and remain usable.
Re-entering requires paying the registration burn again.Your registrations on other subnets are untouched.

Avoiding it

The only durable defence is to score well enough that someone else is always the lowest-ranked non-immune neuron. Monitoring your incentive against the field — which the miner leaderboard on each subnet page shows — tells you how close to the eviction boundary you are.

Before you register

  • Confirm registrations are open on the subnet and check how many UID slots are free.
  • Read the live registration cost immediately before submitting, not hours earlier.
  • Read the subnet's immunity period and confirm you can be productive within it.
  • Have your miner running and tested — ideally on the test network — before you spend TAO.
  • Register your own hotkey, never one associated with the subnet owner.
  • Budget for more than one attempt. Read Start mining for the full workflow.