{"openapi":"3.1.0","info":{"title":"Guitar Chord Builder API","version":"1.0.0","description":"Create printable guitar chord charts and immutable share links."},"externalDocs":{"description":"LLM and REST API guide","url":"https://www.guitarchordbuilder.com/developers"},"servers":[{"url":"https://www.guitarchordbuilder.com"}],"security":[],"paths":{"/api/chord-charts":{"post":{"operationId":"createChordChart","summary":"Create a printable guitar chord chart","description":"Resolves chord names to standard guitar voicings and returns an editable share link plus a direct PDF link.","requestBody":{"required":true,"content":{"application/json":{"schema":{"type":"object","additionalProperties":false,"required":["title","sections"],"properties":{"title":{"type":"string","minLength":1,"maxLength":120},"accidental_preference":{"type":"string","enum":["sharp","flat"],"default":"sharp"},"sections":{"type":"array","minItems":1,"maxItems":12,"items":{"type":"object","additionalProperties":false,"required":["name","chords"],"properties":{"name":{"type":"string","minLength":1,"maxLength":80},"chords":{"type":"array","minItems":1,"maxItems":48,"items":{"type":"object","additionalProperties":false,"required":["name"],"properties":{"name":{"type":"string","minLength":1,"maxLength":40,"description":"Chord symbol. Standard names include major, minor, 7, maj7, m7, sus2, sus4, dim, aug, 6, m6, add9, and slash inversions. Include frets for other chords."},"frets":{"type":"array","minItems":6,"maxItems":6,"description":"Optional custom fingering from low E to high E. Use x for a muted string.","items":{"oneOf":[{"type":"integer","minimum":0,"maximum":14},{"const":"x"}]}},"voicing":{"type":"string","enum":["default","open","sixth_string","fifth_string"],"default":"default"}}}}}}}}},"example":{"title":"Four-chord song in G","sections":[{"name":"Verse","chords":[{"name":"G"},{"name":"D"},{"name":"Em"},{"name":"C"}]},{"name":"Chorus","chords":[{"name":"C"},{"name":"G"},{"name":"D"},{"name":"Em"}]}]}}}},"responses":{"200":{"description":"Chord chart created","content":{"application/json":{"schema":{"type":"object","required":["title","chord_count","share_url","pdf_url","warnings"],"properties":{"title":{"type":"string"},"chord_count":{"type":"integer"},"share_url":{"type":"string","format":"uri"},"pdf_url":{"type":"string","format":"uri"},"warnings":{"type":"array","items":{"type":"string"}}}}}}},"400":{"description":"Invalid or unsupported chord chart"}}}}}}