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SUBMIT A PRSUBMIT AN ISSUElast edit: Oct 11, 2025

Announcements and Developments

This page tracks recent and upcoming changes to the Bittensor protocol and other major events in the Bittensor ecosystem.

Bittensor SDK v10​

Status: In development

  • What: A new major version of the Bittensor SDK is in development and will introduce breaking changes.
  • Key Features:
    • Comprehensive error handling for all extrinsics and related calls.
    • New standardized extrinsic response class with success status, error objects, receipts, and transaction fees in TAO and alpha.
    • Amount handling standardized to balance type only for consistent calculations.

Subnet UID trimming​

Status: Implemented (Merged)

  • What: UID trimming allows subnet owners to reduce the number of neuron UIDs registered on their subnet, compressing the remaining UIDs to maintain consecutive indexing.
  • Key Features:
    • Now allows subnet owners to increase maximum UID count after previous trimming.
    • Removes the lowest-performing neurons based on emission scores.
    • Both temporally immune UIDs and owner-owned UIDs are protected from trimming.
    • After trimming, remaining UIDs are compressed to the left to maintain consecutive indexing

For detailed information, see: UID trimming.

Multiple Incentive Mechanisms Within Subnets​

Status: Implemented (Merged)

  • What: Multiple incentive mechanisms allow subnet owners to apportion emissions across different evaluation criteria, each running Yuma Consensus independently with separate bond pools
  • Key Features:
    • Enables up to 2 incentive mechanisms (IDs 0,1) within each subnet for multi-task validation.
    • Fully backward-compatible with existing miners and validators via mechanism ID 0
    • Each mechanism has its own weight matrix and independent bond pools for consensus calculations
    • All validators participate in all mechanisms with identical stake weights
  • Miners can automatically participate in any of the subnet's mechanisms when registering for a subnet
    • Emission distribution control: Subnet owners can set custom emission distributions using the sudo_set_subsubnet_emission_split extrinsic
    • Immediate mechanism number setting: No onset period - changes take effect immediately
    • Rate limiting: Subnet owners can set mechanism numbers once per 7200 blocks

For detailed information, see: Multiple Incentive Mechanisms Within Subnets

Hyperparameter Rate Limiting​

Status: WIP

  • What: Prevents subnet owners from changing hyperparameters too frequently
  • Rules: Cannot change hyperparameters in last 10 blocks of a tempo
  • Purpose: Prevent exploitation where subnet owners kick off root validators to take full incentives
  • Implementation: Applies 7,200-block rate limit to prevent subnet owner exploitation

See Rate Limits in Bittensor.

Child Key Fee​

A percentage fee will be deducted from emissions bound to validator hotkeys through a child hotkey relationship. This is designed to more highly incentivize validators who perform validation work, over child-key-only validators. It is being gradually rolled out to reduce surprise for the community and allow validators to adjust.

Status: Implemented (Merged)

  • Plan:
    • Start at 1% (September 10)
    • 30-day delay
    • Increase by 1% per day for 17 days
    • Final rate: 18%

Changes to the Subnet Registration/Deregistration Process​

Status: Ready for deployment on September 16, 2025

  • Key Changes:

    • Subnet limit remains at 128 initially with no new registrations available immediately
    • Immunity period reduced from 6 months to 4 months from registration block
    • Network rate limit increased to 4 days between registrations
    • Initial lock cost set at 1,000 TAO with standard linear decay mechanism
    • First deregistrations available approximately September 23 (one week after deployment)

    See: Subnet Deregistration

Auto-Staking for Miners​

Status: Implemented (Merged)

  • What: Miners can automatically stake their mining income to a validator of their choice
  • Implementation:
    • New extrinsics set_coldkey_auto_stake_hotkey and get_coldkey_auto_stake_hotkey
    • Set per coldkey, affects all miner hotkeys
    • No transaction fees required
    • Reduces sell pressure by allowing automatic delegation of mining rewards
    • Event emission system being added to distinguish mining vs staking rewards for proper accounting
    • Requires CLI support for configuration and management

Registration Fee Controls​

Status: Deployed

  • What: Subnet owners can configure neuron registration fees
  • Implementation:
    • Subnet owners can configure neuron registration fees between 0.1 and 1 TAO