Read application, target, capabilities, shared editing workflow and unresolved operations.

Read native parameters with provenance, module guidance/units and an observation token.

Read fields=[] for target/preview without loading adjustment parameters. Read module=... before edits. Parameter targets are absolute, not deltas; skip modules without a visible purpose.

Apply one qualified numeric or structured module using its exact observed module token.

macOS film_grain {type?:fine|silver_rich|soft|cubic|tabular|harsh,impact?:0..100,granularity?:0..100}; Background-only. Structured modules: curves {channel,points:[[x,y],...]}; color_mixer {mode:'basic',color,hue?,saturation?,lightness?} or {mode:'advanced'|'skin',action:'add'|'update'|'remove',rgb? ,index?,hue?,saturation?,lightness?,smoothness?,uniformity_hue?,uniformity_saturation?,uniformity_lightness?,enabled?,inverted?}; levels {channel,input_black?,input_white?,midtone?,output_black?,output_white?}; color_balance {wheel,x?,y?,lightness?}; layers {action,layer_ref?,creation_operation_id?,opacity?}; masks {action:'create_subject'|'create_background'}. Layers also support rename {layer_ref,name}, set_enabled {layer_ref,enabled}, duplicate {layer_ref,name?}, move {layer_ref,index}; index is zero-based excluding Background. Masks on the selected adjustment layer: invert, clear, fill {density:0..1}, copy {source_layer} replaces the entire mask; combine {source_layer,mode:add|subtract|intersect}; feather {radius:0..300}; linear_gradient {start:[x,y],stop:[x,y],midpoint:0.01..0.99}; radial_gradient {center:[x,y],radius_x,radius_y,falloff:0..1,angle:-360..360,inverted:bool}; luma_range {shadow,shadow_falloff,highlight,highlight_falloff,radius,sensitivity,inverted}. Gradient coordinates/radii use normalized RAW dimensions, not rotated viewer coordinates. Luma endpoints 0..255 ordered shadow_falloff<=shadow<=highlight<=highlight_falloff, radius 0..300, sensitivity 0..100. select_submask {index} uses the native indexes returned by masks read; -1 selects the whole mask. Brush/gradient operations follow C1's selected submask semantics. Luma range replaces existing luma components, preserving the other masks. Each color module also accepts {action:'reset'} (C1 defaults) or {action:'paste',source_observation_token} (a saved complete read of the same module). Read the destination module before applying; source snapshot may belong to another layer/photo. Native qualification remains required. No presets or style files are created. Scalar parameters, levels, all mixers, color wheels and curves share the C1 internal model endpoint for Background and the selected adjustment layer. Select a layer then re-read the module; target.layer binds every write to that layer. Native AI masks use AutoMaskingManager without requiring the tool panel to be visible. Levels endpoints use 0..255, midtone -1..1. Advanced H/S/L limits are +/-30, -100..200, +/-100; Skin +/-5, +/-30, +/-10. Smoothness 1..30; Skin uniformity 0..100. Advanced/Skin may also update hue_low/high and saturation_low/high: signed offsets from the source color, low<=-2, high>=2, hue span<=359 degrees. Skin has one range. Read gives current native ranges and indexes; no screenshot or UI color picking is required.

List the active native collection (including offscreen photos), or select by variant_uuid.

Follow next_offset with the same collection_token. next/previous follow the filtered collection. create_candidate clones the selected variant; edits remain restricted to registered copies. macOS supports native collection listing and selection; consult context for platform restrictions.

Check context capabilities first. macOS requires explicitly enabled kind=render JPEG exports.

On Windows, default native renders current C1 adjustments asynchronously, without export or focus.

kind=mask renders the selected layer's whole composite mask. max_size is 128..1600. map_points maps {x,y} pixel-edge coordinates using C1's nonlinear transform; use the same kind/max_size and returned preview_id. Divide RAW x/y by raw_dimensions to make normalized gradient coordinates. A changed photo, layer or revision invalidates the id. Only the most recent preview job is retained; eight PNG cache files are retained. Legacy kind=render exports, kind=viewer/action=capture samples the display.

Get/list/reconcile existing receipts; reconcile never dispatches recovery writes.

action=task adds persistent photographic briefs and versions on Mac. Mutations require a unique request_id and fresh target/token (stop only needs task_id). task_action: start payload={goals:[...],protections:[...],mode:optimize|reference_match,strength:light|close|maximum, references:[{id,role,kind:same_scene|cross_scene}],reference_analysis?:{tone,color,texture,limitations,priority}}; bind {candidate_request_id}; update merges brief fields; checkpoint {preview_request_id,label}; review {checkpoint_id,seen_sha256,improved:bool,assessment:{goal,protections,light_color,edges,remaining,reference?}}; feedback {kind:brightness|temperature|strength|subject|background|prefer_previous|custom,message,protect?:[...],checkpoint_id?}; accept {checkpoint_id,user_confirmation}; restore {checkpoint_id} WRITES saved selected-layer color parameters through adjust, without restoring layer structure/mask pixels. Render/review again. get/diagnose/compare are read-only; compare {roles:[initial,previous,current,accepted]} returns images. Reference images and visual judgments are supplied by the vision client; the backend cannot prove aesthetics. P1 reference_plan {checkpoint_id,targets:[{id,reference_id,observation,uncertainty,region,direction, protect:[...],priority:1..5,limitation}]}; IDs reference the current brief, priority 1 is highest. recognize {checkpoint_id,aspect,user_confirmation,supersedes?:[recognition_id]} records partial USER approval. feedback may add interpretation:{problem,region,direction,method:global|color_range|local|inspect_only,risks}. P1 checkpoints freeze intent. review additionally requires exact id/status/note lists for captured target_results (pending|close|conflict|limited), protection_results (preserved|changed|uncertain), feedback_results (resolved|improved|unchanged|worse|conflict). See checkpoint.intent for required IDs. compare can alternatively use {checkpoint_ids:[...]} for up to three recognized historical versions. anchor_analysis measures actual-render patches without writing C1. payload={checkpoint_id,reference_id, reference_checkpoint_id OR reference_path+reference_sha256,assume_srgb?:{reference:bool,target:bool}, anchors:[{id,role,kind:neutral|color,reference_box:[l,t,r,b],target_box:[l,t,r,b]}]}. Boxes use normalized EXIF-oriented preview coordinates, never RAW/mask coordinates. No automatic neutralization. Reuse fixed anchors with {checkpoint_id,baseline_analysis_id,alignment_confirmed:true} after looking at the new render. An embedded ICC is converted; untagged RGB requires explicit assume_srgb. Lab deltas are not C1 slider values. reference_plan may link anchor_analysis_id from its current checkpoint. References must be explicitly provided images.