Intent
What is being built, written as a spec the plan traces back to, not a prompt that disappears with the session.
Concept
Keep the work agreement and implementation evidence together.
Day Shift is a local CLI that keeps coding-agent plans, scope, validation evidence, and handoff records in your repository. These records give humans and coding agents a shared continuation point across sessions, tools, and contributors.
What belongs in the contract
Five things every agent handoff should leave behind.
Day Shift stores each element as a plain repository file, so the contract is reviewable, versioned, and readable by the next human or agent.
Scope
Which files and behaviors a task is allowed to touch, declared before the agent writes code.
Validation evidence
The required checks are named up front, and their executed, recorded, or imported results remain visible beside the work.
Evidence
What actually changed and what actually passed, recorded in an implementation summary beside the code.
Review and disposition
Read-only review findings stay separate from the explicit action that accepts, revises, blocks, cancels, or closes the work.
The category, after the concrete workflow
A durable contract for the next human or agent.
Together, the work agreement and implementation evidence form a Human-Agent-Contract.
Day Shift records the work agreement and implementation evidence. Review is read-only; acceptance and closure are explicit actions.
Day Shift exposes collaboration policy to compatible agents but does not grant unlimited authority or force unsupported agents to comply.
The current Day Shift CLI can execute a task revision's complete declared validation set in order with `task validation-set`, execute one explicitly selected command with `task validation-record`, or import evidence produced elsewhere. Declared-set execution rejects arbitrary extra argv, records every command independently, and stops on the first required failure.
Deterministic versus model-assisted
Not every layer of the contract needs a frontier model.
Workflow structure reduces required model capability. Day Shift makes the routing explicit.
Deterministic checks
The CLI can check structure, traceability, and readiness without asking a model to infer those mechanical contracts.
Smaller models
Routine planning and summarization layers work with the models you already have access to.
Frontier models
Reserved for ambiguous product intent, architecture decisions, risky changes, and conflicting evidence.
Where Day Shift fits
Day Shift is the repository-native home for the contract.
Day Shift organizes and preserves agent-assisted engineering work. It does not replace the coding agent, Git, CI, issue tracking, or code review.