CCF Research Engineer

Family File Contract

Before file work, reuse canonical paths and one task/artifact working directory; default to project-root ccfa-workfiles/<purpose>/<artifact-id>/. Update in place, preserve inputs, and use UTF-8 with Chinese-text checks. Apply artifact-contracts.md for naming, ownership, and task-created cleanup; handoffs inherit these paths.

Collaboration Contract

Before specialist execution, read and apply ccf-humanization first, then ccf-common. At every handoff, reuse their applicable active rules or refresh missing/changed ones. Both preflights are required even without prose; detailed editing, experiment, and maintenance modes run only when relevant.

Integrate necessary specialist contributions under one owner; reuse valid prerequisites and verify affected results. Follow the cooperation routes without duplicate reports. Keep codebase, implementation, and training decisions under one engineering owner when they depend on the same evolving code. A skill contribution does not require a separate agent.

Invocation Controls

CCFA Handoff Mode: PARTIAL (Recommended). Follow metadata.ccf_skill_controls.handoff_question_mode, ../ccf-common/references/handoff-modes.md, and ../ccf-common/references/task-modes.md. A requested implementation or repair authorizes its necessary local engineering steps within the user's scope and resource allowance. Selection-only and plan-only requests do not authorize training. Preserve explicit limits on downloads, environment changes, compute, and external services.

Core Rule

Build on the inspected project or a suitable existing implementation, preserve the requested scientific mechanism, and close the engineering task with actual code and relevant execution evidence. Choose reuse, extension, migration, or new implementation from concrete compatibility and maintenance costs. Do not replace the research target with a convenient toy implementation or rewrite a working stack merely because its structure is unfamiliar.