tl;dr: pxpipe is a local proxy that rewrites bulky Claude Code request context (system prompts, tool docs, older history) into PNG images, exploiting the fact that dense text packs ~3.1 chars per image-token vs ~1 char per text-token, cutting end-to-end costs ~59-70% on Fable 5. The tradeoff is lossy verbatim recall — exact strings like hashes and IDs can silently confabulate, so it's gated to token-dense content and specific models (Fable 5, GPT 5.6), with recent turns and byte-exact data kept as text. SWE-bench results show near-parity with 60-65% token reduction.