Packaging and Deployment

Establish the artifact contract

Read references/system-selector.md.

1. Record engine revision, project commit, target platform, architecture, target type, build configuration, device profile, distribution channel, and base release when patching.
2. Define the artifact: Development/Test/Shipping, client/server, container format, chunks, symbols, prerequisites, archive, deploy destination, and acceptance tests.
3. Separate Build, Cook, Stage, Package, Deploy, and Run. Identify the first failing phase.
4. Reproduce with a saved Project Launcher profile or recorded AutomationTool command.
5. Preserve the complete log, exit code, manifests, artifact hashes, size report, and symbol identity.
6. Run from a clean staging/archive location and test without editor binaries, loose source content, developer config, or a cook server.
7. Promote the exact tested artifact; do not rebuild after approval.

Route neighboring work deliberately:

• asset schemas, Primary Asset rules, and content-to-chunk ownership -> unreal-data-assets-tables;
• commandlets, Data Validation, and automation tests -> unreal-editor-automation;
• runtime loading, residency, PSOs, and load hitches -> unreal-memory-streaming;
• packaged performance captures -> unreal-insights-profiling;
• save-format compatibility across releases -> unreal-save-load.

Load only what applies:

• references/build-configurations-targets.md
• references/build-cook-stage-package.md
• references/cooking-inclusion-validation.md
• references/uat-project-launcher-ci.md
• references/containers-chunks-patches-dlc.md
• references/config-staging-runtime-dependencies.md
• references/plugins-sdks-platforms.md
• references/symbols-logs-crash-reporting.md
• references/release-reproducibility-security.md
• references/diagnostics-recipes.md

Required answer format

Return:

1. Artifact contract and target matrix.
2. Exact pipeline surface: editor, Project Launcher, commandlet, UAT, or CI.
3. Ordered Build/Cook/Stage/Package/Deploy actions and owned configuration.
4. Cook roots, maps, chunks, staged files, plugins, SDKs, and platform prerequisites.
5. Symbols, logs, crash collection, version/build ID, archive, and security policy.
6. Clean-device verification, failure injection, patch/base compatibility, and pass criteria.
7. First causal error with the smallest confirming experiment when diagnosing.

Hard rules

• Use Cook By the Book and a packaged target build for QA/release evidence; Cook On the Fly is an iteration service, not a distributable artifact.
• Never use -cookall, broad always-cook directories, or loose copied assets as the first fix for a missing dependency. Identify the intended cook root and prove it in manifests/artifacts.
• Never infer success from AutomationTool exit alone. Launch, traverse, save/load, network, suspend, and platform-test the staged artifact required by the release contract.
• Keep source defaults, platform overrides, generated user config, and secrets separate. Inspect the staged effective configuration and strip denied keys/sections.
• Declare third-party runtime files through build/staging rules; do not repair a release by manually copying an untracked DLL beside one machine's executable.
• Preserve symbols outside the public artifact and map them to the exact executable/build identity.
• Build a patch against the exact retained base release. Never regenerate or silently replace the base.
• Treat signing/encryption keys as release secrets. Encryption can increase patch entropy and IO cost; measure the chosen policy.
• Test the distribution path on clean target hardware with the correct account, SDK/runtime, permissions, storage state, and no editor installation.
• Do not invent UAT flags or platform requirements. Inspect BuildCookRun -Help, the generated Project Launcher command, UE 5.8 source, and the target platform's current restricted documentation.

See references/sources.md for the UE 5.8 primary-source trail.