Nine Easel sessions, read back: Bash was 70–85% of every one, and the calls before the first edit were the same hunt each time — grep graph.mjs for `function circle(`, sed a window of disk.mjs, grep disks/ for a `synth({`, page notepat.mjs in 80-line slices. A minute or two per session on a surface that does not change. So the surface is computed once. bin/build-api-map.mjs reads the paint API off disk.mjs and graph.mjs into context/api.json (87 entries: runtime signatures, docs, real call sites), and src/tools.mjs serves it as a dependency-free MCP server over stdio — ac_api, ac_examples, ac_outline, ac_symbol — passed to the Claude bridge with --mcp-config and pre-allowed. The guides are inlined into the first turn instead of named, and the in-repo list now includes the piece authoring guide. The map travels with the context bundle: `npm run context` rebuilds it, `npm test` fails when it is stale. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>