This technical blog post details the implementation requirements and mathematical foundations for integrating SPEEDEX, a novel scalable decentralized exchange design, into Stellar-core. It covers the three main protocol changes needed, the Arrow-Debreu economic model underlying SPEEDEX, and the Tâtonnement algorithm used for efficient price computation.
The article provides a comprehensive technical deep-dive into integrating SPEEDEX into Stellar. It outlines three core changes: introducing a multi-phase ledger with commutative transactions for order batching, extending transaction preconditions to prevent double-spends, and limiting asset issuance to INT64_MAX units. The post explains how SPEEDEX leverages Arrow-Debreu exchange market theory and linear utility functions to compute equilibrium prices. It details the Tâtonnement iterative algorithm for price discovery, which uses binary search optimization to achieve logarithmic complexity in the number of trade offers. The article also discusses how approximation error is handled via linear programming and notes that buy offers present computational challenges that may require alternative integration approaches.
