Lumen MCP Server

lumen

Lux in motu — light in motion. A cross-platform, cross-media conversion engine, written in Rust (edition 2024, rmcp 3.8.0): one operation core that bridges media formats — 2D art and sprite formats, 3D models, and game-engine packages — converting between them deterministically from code-first records, so the same input record yields the same output on any platform. Aseprite sprites and Bevy were its first endpoints, not its purpose; the center is the factory (one identity record, emitted as 2D or 3D) and the named, verified converter chain between formats — one operation core behind three surfaces —

• MCP tools for interactive media work: sprite operations, inspection, palettes, text, style presets, dream-animation automation, QA gates, and export backends (PNG sheets, WASM-4, TIC-80, VoidSprite file interop). All paths are project-root bounded.
• An A2A agent surface (v0.3.x JSON-RPC) for dispatched, long-running art jobs, with the trial-then-approval art-director loop as a protocol state. See A2A_DESIGN.md.
• A deterministic policy layer (APPA-style, adapted from archestra-ai/OpenAPPA): every tool call is checked against lumen-policy.toml before it executes, decisions are replayable, and denials name the rule they violated. See POLICY_DESIGN.md.

Companion strategy — pair, don't duplicate — is in COMPANIONS.md. How lumen was built, in what order, and under what governance (including the evidence rule its first failed build produced) is in HISTORY.md.

Canon machinery (B2, 2026-10-28, D-292/D-312)

Character generation and derivation run against a single canon record per character (canon-record/1), enforced by four tools (15 registered total at 1.0.0; the 11 pre-B2 tools are unchanged):

• canon_resolve — handle (canon://<lane>/<character>@<version>

  • record SHA-256) → record summary. Lane law in server code: nsfw records are refused to qompass-lane callers; unclassified defaults to nsfw. Records live in the SFW store under the project root (canon/<lane>/<character>.json); lumen never persists an adult record.

• canon_gate — measurements → verdict over proportion and register bands (ink colour, stroke weight, shadow-edge hardness, saturation/contrast percentiles, key-light direction, iris spec, blush). Drift returns a typed drift_detected refusal with per-metric deltas. PASS releases an artifact to the eye sheet, never to adoption.

• canon_generate — anchored generation broker. There is no unanchored mode: a job requires a canon handle, an anchor role, the keeper anchor + style-authority hashes among its inputs, and turnaround + plate reference inputs (reference conditioning). Jobs anchored outside the Owner-adopted keeper set are refused pre-generation. Every job persists a workflow-JSON provenance receipt (canon-receipts/<job_id>.json, digest-verified; tampering is detectable), and any supplied outputs are gated before the job returns as admitted.

• canon_convert — handled conversion (1.0.0, R-607): a project PNG is remapped under the record's fingerprint palette (nearest palette colour within its tolerance; out-of-tolerance pixels keep their colour and are counted) and the result is gated against the record's bands before anything is written — drift writes nothing. There is no unhandled mode on this tool; the pre-canon conversion tools keep their existing behaviour without a handle (SPEC §6).

The format/handle/gate crate is crates/lumen-canon (package lumen-canon, lib canon_record), absorbed from the B1 reference implementation without re-derivation.

Also at 1.0.0: the Phase F motion evaluator leg is verified landed in crates/lumen-rig-core (MOTION-EVALUATOR.md), and the sprite→3D fidelity metric (silhouette IoU + landmark Δ) ships in crates/lumen-factory with its first measurement on record (crates/lumen-factory/FIDELITY.md). The server package is lumen-mcp-server 1.0.0 (D-298 rename; the library crate remains lumen). EFLO for the 15-tool surface: EFLO.md. Utilization evidence: UTILIZATION.md.

Verified state (1.0.0, 2026-10-29, both machines)

• Workspace 557 tests passed / 0 failed / 8 ignored (including lumen-canon's 39), lumen-rig-core 93 / 0, lumen-factory 149 / 0; fmt clean; clippy -D warnings clean (resolved clippy 0.1.100, nightly-2026-09-25 pin) on sandbox and primo; Diver gate at the primo mirror. (Suite split between validation and adversarial cases.)
• Live interop gate against real Aseprite 1.3.18.6-dev and Bevy 0.18 BRP (scripts/interop_check.sh): 5 passed / 3 failed — the failures are documented premise mismatches between lumen's assumptions and the real tools' behavior; see HISTORY.md.

Layout

• src/ — operation core: sprite_ops, inspect, palette, text, style, dream, qa, export, pipeline, policy, bevy, doc, vrm, and the a2a/ surface (mod, task, http, registry).
• tests/ — validation and adversarial suites, incl. interop.rs (live-tool gates, ignored by default).
• lumen-policy.toml — the shipped policy; lumen policy check and lumen policy replay are its gates.

License

This project is licensed under the Apache License, Version 2.0.