[BFT-A][EPIC] Implement CBE Curve Spec in Ordered Rollout

[umwelt]

Title

[BFT-A][EPIC] Implement CBE Curve Spec in Ordered Rollout

Purpose

This meta issue is the authoritative execution-order controller for the CBE curve work defined by:

• CBE Bonding Curve — Complete Formula Reference
• CBE Bonding Curve — Rust Implementation Specification

It does not replace the implementation issues. It defines the sequence they must land in so the branch converges on one canonical curve engine without scope drift.

Locked Team Decisions

• GRAD_THRESHOLD = 2_745_966 * SCALE
• SELL_CBE is controlled by explicit protocol flag sell_enabled: bool
• sell_enabled = false at genesis and may become true later by config/upgrade
• treasury_locked is out of scope on this branch
• SELL_CBE solvency is reserve-only

Ordered Rollout

Phase 1: Canonical Shapes

1. [BFT-A][R8] Establish canonical CBE curve types and fixed-point state model #1923 [BFT-A][R8] Establish canonical CBE curve types and fixed-point state model

• Define authoritative types in lib-types
• Lock canonical mutable curve state and u48 nonce representation

2. [BFT-A][R9] Replace curve arithmetic with 18-decimal U256 fixed-point math and deterministic integer sqrt #1924 [BFT-A][R9] Replace curve arithmetic with 18-decimal U256 fixed-point math and deterministic integer sqrt

• Lock arithmetic contract before implementing execution

3. [BFT-A][R8] Collapse CBE curve math to one canonical piecewise-linear engine #1925 [BFT-A][R8] Collapse CBE curve math to one canonical piecewise-linear engine

• Build one pure math engine for price, buy, and sell computations

Phase 2: Wire Format and State Authority

4. [BFT-A][R9] Add fixed-width BUY_CBE and SELL_CBE transaction payloads #1928 [BFT-A][R9] Add fixed-width BUY_CBE and SELL_CBE transaction payloads

• Lock byte-level transaction format

5. [BFT-A][R4] Persist canonical CBE curve state and restart reconstruction inputs #1926 [BFT-A][R4] Persist canonical CBE curve state and restart reconstruction inputs

• Establish persisted state authority for restart/replay

6. [BFT-A][R4] Rework genesis to initialize zero-state CBE curve economics #1927 [BFT-A][R4] Rework genesis to initialize zero-state CBE curve economics

• Make genesis/config authoritative for zero-state curve deployment

Phase 3: Execution Cutover

7. [BFT-A][R8] Add dedicated CBE curve executor lane and remove disabled legacy dispatch #1929 [BFT-A][R8] Add dedicated CBE curve executor lane and remove disabled legacy dispatch

• Introduce canonical execution lane

8. [BFT-A][R9] Implement canonical BUY_CBE issuance per mint-on-buy spec #1930 [BFT-A][R9] Implement canonical BUY_CBE issuance per mint-on-buy spec

• Land the canonical buy path first

9. [BFT-A][R8] Implement canonical SELL_CBE redemption and solvency checks #1931 [BFT-A][R8] Implement canonical SELL_CBE redemption and solvency checks

• Land canonical sell path with sell_enabled gating and reserve-only solvency

Phase 4: Hardening and Governance Boundary

10. [BFT-A][R9] Remove runtime/background mutation and isolate curve graduation to block execution #1932 [BFT-A][R9] Remove runtime/background mutation and isolate curve graduation to block execution

• Remove non-canonical runtime mutation paths

11. [BFT-A][R6] Freeze immutable curve logic and gate curve parameter changes behind protocol upgrade #1933 [BFT-A][R6] Freeze immutable curve logic and gate curve parameter changes behind protocol upgrade

• Lock immutable-vs-upgrade-gated boundary after core implementation is stable

Implementation Rule

Do not skip ahead in a way that makes later issues rewrite earlier authoritative work.

Allowed parallelism:

• Minor prep work is allowed if it does not change authoritative state/math/tx behavior.
• Canonical execution should follow the phase order above.

Done Criteria

• All linked issues are complete in the order above
• The branch implements one canonical CBE curve engine matching the two authoritative docs
• No legacy/generalized path remains authoritative for curve consensus behavior

[github-actions]

This GitHub issue outlines the roadmap for implementing the CBE Bonding Curve specification as a canonical engine through a structured and ordered rollout process. The goal is to create a convergence towards one authoritative curve implementation, guided by specifications documented in two authoritative references: the formula and Rust implementation details. The rollout is divided into four sequential phases: defining canonical curve shapes and math (Phase 1), establishing wire formats and state authority (Phase 2), handling execution cutover for buy and sell mechanics (Phase 3), and hardening governance boundaries to freeze immutable curve logic (Phase 4). Locked team decisions set key operational parameters, such as sell_enabled gating and reserve-only solvency for SELL_CBE. Implementation issues are linked for each step, ensuring dependencies are resolved in the prescribed order without scope drift, while allowing minor preparatory work that respects the integrity of earlier authoritative work. The final deliverable is a clean, canonical CBE curve engine with all legacy paths removed, strictly adhering to

[umwelt]

All 11 ordered rollout issues are complete and merged:\n- #1923 #1924 #1925 (Phase 1)\n- #1928 #1926 #1927 (Phase 2) — #1926/#1929 via PR #1941, #1932/#1933 via PR #1946\n- #1929 #1930 #1931 (Phase 3)\n- #1932 #1933 (Phase 4)\n\nOne canonical CBE curve engine is in place. No legacy path remains authoritative.