---
id: PLN-0076
ticket: render-frame-packet-boundary
title: Capabilities and ABI Domain Split
status: done
created: 2026-05-25
ref_decisions: [DEC-0030]
tags: [gfx, renderer, runtime, frame-composer, architecture, ui, pipeline]
---

## Briefing

Source decision: `DEC-0030`.

Split render capabilities and syscall metadata so `composer`, `gfx2d`, and `gfxui` are independently addressable and enforceable according to `AppMode`.

## Target

Capability gates reject wrong-domain render syscalls, and metadata no longer treats the old primitive `gfx.*` ABI as the single render surface.

## Scope

- Add or rename capability flags for `COMPOSER`, `GFX2D`, and `GFXUI`.
- Update syscall metadata for all render-domain calls.
- Enforce domain availability by `AppMode::Game` and `AppMode::Shell`.
- Update resolver and capability tests.
- Preserve `composer.*` as Game 2D high-level composition.

## Out of Scope

- Implementing command buffers.
- PBS stdlib author-facing wrappers.
- Host rendering.
- Backward compatibility for the old primitive `gfx.*` ABI.

## Execution Sequence

1. Locate capability definitions, syscall registry metadata, and resolver tests.
2. Introduce separate render capability identifiers for `composer`, `gfx2d`, and `gfxui`.
3. Update metadata for existing composer calls and new or renamed primitive domains.
4. Add app-mode checks so Game exposes `composer` and `gfx2d`, while Shell exposes `gfxui`.
5. Replace stale tests that assume one graphics capability.
6. Run resolver and runtime syscall tests.

## Acceptance Criteria

- Wrong-domain calls fail before mutating render state.
- Game mode cannot use `gfxui.*`.
- Shell mode cannot use `composer.*` or `gfx2d.*`.
- Capability metadata uses the split domain names.
- No compatibility promise remains for the old primitive `gfx.*` ABI.

## Tests / Validation

- Add resolver tests for all three capabilities.
- Add app-mode enforcement tests for allowed and rejected calls.
- Run affected unit and integration tests.

## Risks

- A large rename can hide semantic mistakes; verify every syscall maps to the correct domain responsibility.
- Author-facing stdlib names may still use `gfx`; keep this plan focused on ABI metadata.

## Affected Artifacts

- Syscall metadata and resolver modules under `crates/`
- Capability tests