Poster manifest 2.0

Purpose

The manifest is the only content input to the generator. It binds:

• approved text and images;
• exact source IDs;
• local asset hashes and licenses;
• PowerPoint canvas and physical output geometry;
• conference and printer rules;
• accessibility/quality thresholds and their basis;
• reading order;
• author approval to a canonical content hash.

Unknown keys, duplicate JSON keys, non-finite numbers, remote asset paths, path escape, unapproved fields, unresolved sources, unused records, and common placeholders are rejected.

Template

assets/poster_manifest_template.json is intentionally invalid. It contains replacement tokens, false confirmations, and draft approval so it cannot produce a poster accidentally.

Copy it into a project directory, then replace every field with reviewed values. Asset paths are relative to that manifest's directory.

Top-level object

Manifest version 2.0 requires exactly these keys:

• schema_version
• document
• canvas
• physical_output
• requirements
• quality
• palette
• sources
• assets
• elements
• approval

The validator rejects extensions to the schema rather than silently ignoring them.

document

• id: stable identifier beginning with a letter.
• title: exact approved title, at most 255 characters.
• subject: exact approved description for core document metadata, at most 255 characters.
• language: BCP 47-style language tag.
• authors: exact ordered author names; joined by ; they must fit the 255-character core-property limit. No author is silently dropped or shortened.
• source_ids: exact records supporting title, subject, language, and author metadata.

Exactly one text element with role title must match document.title verbatim. It must have reading_order: 1; generation uses it as the native PowerPoint slide title placeholder rather than as an undifferentiated text box.

canvas

• width_in, height_in: PowerPoint slide dimensions, each 1–56 inches.
• background_color: opaque six-digit sRGB hex.

These are design dimensions, not automatically the physical trim size.

physical_output

• trim_width_in, trim_height_in: finished physical dimensions.
• bleed_in: physical bleed on each edge.
• safe_margin_in: inset inside the trim edge for non-bleed content.
• orientation: portrait, landscape, or square, matching trim dimensions.

The physical artboard is trim plus twice the bleed. It must share the canvas aspect ratio.

requirements

conference

The organizer record must be confirmed and provide:

• exact source_id;
• maximum width and height;
• orientation (portrait, landscape, square, or either);
• required delivery format (PDF, PPTX, PDF_AND_PPTX, or OTHER);
• notes copied or summarized from the verified rule.

The physical trim dimensions must fit. The referenced source record must have kind conference_rule.

printer

The printer record must be confirmed and provide:

• exact source_id;
• trim width/height, bleed, and safe margin matching physical_output;
• accepted color mode (RGB, CMYK, or PRINTER_MANAGED);
• whether uniform scaling is allowed;
• notes describing the confirmed workflow.

If scaling is forbidden, canvas and physical artboard must be 1:1. A CMYK requirement does not prevent creation of an editable RGB PPTX, but the export plan blocks a claim of print readiness pending printer-approved conversion/proof. The referenced source record must have kind printer_rule.

quality

• minimum_font_pt_final
• font_guidance_basis
• font_guidance_source_id
• minimum_raster_dpi_final
• raster_dpi_basis
• raster_dpi_source_id

Basis values are:

• heuristic
• source_specific
• conference_requirement
• printer_requirement

A heuristic must have a null source ID. Every other basis requires an exact source ID. Values apply at final physical output, after uniform scaling.

palette

colors maps stable IDs to opaque #RRGGBB sRGB values.

Each contrast_pairs record contains:

• id
• foreground_color_id
• background_color_id
• usage: normal_text, large_text, or non_text

The validator applies 4.5:1 to normal text and 3:1 to large text/non-text. A text element using large_text must be at least 18 pt final, or at least 14 pt final and bold.

data_series_redundant_encoding must be true. This is an author confirmation that color is supplemented by labels, shapes, markers, patterns, or line styles. It is not an automated certification.

sources

Each source has:

• id
• kind
• citation
• locator
• author_verified: true

Kinds include author content, publication, dataset, asset license, conference rule, printer rule, institutional rule, and other.

Every source must be used, and every referenced ID must exist. The scripts do not resolve URLs, DOIs, or local records.

assets

The array may be empty: figures, logos, and QR codes are optional. Only local PNG/JPEG assets are accepted when an asset is present. Each record has:

• id
• manifest-relative path
• role: figure, logo, or qr_code
• lowercase SHA-256
• exact source_id
• license: exact license or permission statement
• provenance: exact author-verified origin or generation record
• concise alt_text
• author_approved: true
• qr_target

qr_target is null except for QR assets, where it is an exact https:// URL. Files are bounded, final symlinks are rejected, paths cannot escape the manifest directory, and hashes must match.

All asset records must be placed in the poster. Use one asset record for repeated placement of the same file; duplicate asset paths are rejected.

The image inventory rejects EXIF, XMP, comments, and embedded text/application metadata to avoid publishing hidden or location-identifying information. Flatten and strip such metadata in an author-reviewed offline workflow, then hash and approve the resulting pixels as a new asset. ICC profiles and basic technical image fields are reported but not silently removed.

elements

Elements are listed in ascending, contiguous reading_order from 1. The list order is not silently changed.

Every element has:

• id, type, and reading_order
• design coordinates x_in, y_in, width_in, height_in
• one or more exact source_ids
• author_approved: true
• allow_in_bleed

All boxes must stay on the canvas. Non-bleed elements must remain inside the physical safe area mapped to the canvas. Text can never be allowed in bleed.

Text elements

Text elements also specify:

• role
• exact text
• font_size_pt_design
• font_face
• bold
• horizontal and vertical alignment
• contrast_pair_id
• optional line_color_id
• line_width_pt
• margin_in

Roles include title, authors, affiliation, heading, body, caption, reference, acknowledgement, contact, QR fallback, and other.

Font size is checked after physical scaling. Text auto-shrink is disabled during generation.

Image elements

Image elements also specify:

• asset_id
• fit: "contain"
• fallback_text_element_id
• long_description_element_id

Contain fitting preserves aspect ratio and centers the image. A QR asset requires a square box and a fallback text element whose role is qr_fallback and whose text contains the exact qr_target. Other assets use null fallback IDs.

long_description_element_id is null when approved alt text and adjacent native text are sufficient. For a complex figure that needs a longer explanation, it references an approved native text element with role body, caption, or other. That element must follow the image in reading order and include every source ID used by the image. QR assets use the required visible fallback text and therefore set this field to null. The reference is structural; a human must decide whether the description is complete.

Approval

Draft form:

{
  "status": "draft",
  "approved_by": null,
  "approved_at": null,
  "content_sha256": null
}

After all non-approval fields validate:

python -B scripts/validate_manifest.py poster.json \
  --print-content-hash

Give the exact manifest and reported hash to the author. Approved form requires:

• status: "approved"
• nonempty approved_by
• ISO 8601 approved_at with UTC offset
• exact lowercase content_sha256

The hash covers every top-level field except approval, using canonical sorted UTF-8 JSON. Any content, source, requirement, palette, coordinate, or asset-metadata change invalidates approval. The generator preserves the approval timestamp in its report and converts it to UTC for the PPTX created/modified core properties, as required by python-pptx; the original UTC offset is not stored in those properties.

Validation modes and exit codes

Normal validation reads and hashes assets and requires approval:

python -B scripts/validate_manifest.py poster.json

--structure-only skips file reads/hashes but still validates path syntax. Use it for planning/audit only, never generation.

--print-content-hash permits draft approval but does not permit placeholders, unverified sources, unapproved elements, or false requirements.

CLIs use:

• exit 0: pass;
• exit 1: completed audit found a release-blocking issue;
• exit 2: invalid input, unsafe input, missing dependency, or command error.