BIP (Bitcoin Improvement Proposal)

A BIP - Bitcoin Improvement Proposal - is a formal design document proposing a change or addition to Bitcoin's protocol, software, or standards. The BIP system, modeled on Python's PEP process, is how Bitcoin's open-source development actually proposes, debates, and codifies changes.

Anyone can write a BIP. The process, defined in BIP-1 and BIP-2:

1. Draft. Author writes the proposal in the standard BIP format - abstract, motivation, specification, rationale, backwards compatibility, etc.
2. Discussion. The draft is shared on the bitcoin-dev mailing list and Github. Anyone interested - developers, miners, users, researchers - reviews and comments.
3. Assignment. If the proposal is well-formed and worth a number, the BIP editors assign it a permanent BIP number.
4. Iteration. The author revises based on feedback. Many BIPs never make it past this stage.
5. Status progression. Draft → Proposed → Final (if widely accepted and implemented) or Withdrawn / Rejected / Replaced.
6. Actual deployment. Acceptance into Bitcoin Core (or other implementations) is a separate decision. Activation on the network requires voluntary adoption by node operators and, for consensus changes, signaling by miners.

BIP types:

• Standards Track - changes to the protocol itself (consensus rules, network protocol, peer-to-peer messaging). Examples: BIP-141 (SegWit), BIP-340/341/342 (Schnorr / Taproot), BIP-352 (Silent Payments).
• Informational - design guidelines or implementation notes, no consensus impact.
• Process - changes to the BIP process itself.

The BIP process is intentionally slow, conservative, and adversarial - the formal end of Bitcoin governance, where developers, miners, node operators, users, and long-term holders each hold de facto veto power. A consensus-affecting change typically takes years from initial proposal to network activation - and many proposals never make it. This is a feature: a global monetary protocol with $1-2T in value should be very, very hard to change accidentally. See SegWit and Taproot for two BIPs that did make it all the way through.