Derive
The parent hash, height and complexity deterministically produce the puzzle.
Scheduled proof-of-golf
Short programs. Daily slots.
Solve the puzzle. Golf quality scores 1–9 points; strictly taller valid branches win. No nonce grinding.
A hobby chain built in Sigil. Not settlement-grade security.
(lambda(x) …)par − 56 GOLF POINTS
How it works
A daily slot for a short program.
Every node derives the same input/output examples and syntactic constraint. Models and synthesis scripts search for short programs. The generated par witness is a valid fallback; block production does not require hash search.
Synthesize
Models, scripts and humans search the frozen puzzle language for a short function.
Verify
Nodes rerun the program under fixed fuel, memory, string and depth caps.
Submit
When the next exact slot is due, build and submit one complete block with nonce and coinbase locktime set to zero.
Fundamentals
Small programs. Fixed rules.
One compact chain. Every headline number comes from the protocol, not a market feed.
- 1–9 pointscompetition quality only
- 86400 secondsexact mainnet slots
- 512 bytessolution cap
- Zeropremine
- 143029.99991970 SGLscheduled maximum
- 8maximum co-op shares
Layered consensus
Longest height. Release checkpoints.
Bounded evaluation establishes a program's validity and byte length. Golf score displays competition quality only: it neither selects canonical branches nor currently alters subsidy.
Bitcoin foundation
80-byte headers, transactions, UTXOs, script, P2WPKH, headers-first sync and block relay.
Frozen puzzle machine
A small Scheme subset with no I/O, mutation, floating point or host eval; one bounded machine checks every example.
Scheduled proof-of-golf
Version commits producer length and puzzle complexity. Bits stays fixed for header compatibility. Nonce and coinbase locktime are zero; non-genesis graffiti is empty.
Puzzle-complexity retarget
Every 16 blocks, median golf margin moves puzzle complexity C. Mainnet slots stay exactly 86400 seconds apart; no hash difficulty is searched or retargeted.
Co-op commit–reveal
Producers require L ≤ par; up to 8 signed personalized shares require L < personalized par and split a 10% contribution pool.
Header and golf score
Version uses prefix 0x20600000 under mask 0xffe00000, with L−1 in bits 20..12 and C in bits 11..0. Valid producer programs satisfy L ≤ par. Savings are min(8, max(0, par − L)); block score is 1 + savings, from 1 through 9. Genesis contributes zero. The 80-byte header keeps fixed per-network bits and nonce zero; non-genesis coinbase locktime is zero, graffiti is empty, and transaction version and sequence remain canonical. There is no hash admission target.
Fork choice
A valid candidate branch must be strictly taller to replace the active chain. Equal height retains the durable active incumbent, including after restart; golf score, hash and arrival metadata never displace it. Chain configs publish hardcoded (height . internal-hash) checkpoints: incompatible branches cannot cross them. Checkpoints advance only in reviewed software releases, and nodes must upgrade to share newer checkpoints. Mainnet currently pins H0 and H1 on the replacement slogan chain; public testnet and regtest remain H0-only, protecting genesis but no later history. Reorgs remain possible above H1 on mainnet and above H0 on testnet and regtest.
Exact slots and puzzle retarget
Header time must equal parent time plus the configured spacing: exactly 86400 seconds on mainnet, shorter on test networks. No network allows a future slot. Missed slots can be filled late, so this is not a guarantee of daily block arrival. Every 16 blocks, median relative golf margin adjusts C, changing grammar width, examples and constraint tier. Bits and validator caps never move.
Payout and issuance
Solo pays floor(4S/5)+fees and leaves the reserve unminted. With shares, canonical outputs divide floor(S/10) by verified contributions 1–4, pay the parent floor(S/20), retain zero-value required outputs, and send fees and integer residuals to the producer.
