dfg-inc/praxis-architect/context-slice

Context Slice

Give Developer only what this package needs: applicable decisions, contracts, NFR budgets, must-read paths — not the whole architecture corpus. Boundaries are named explicitly (WBS 4.14.1).

When to use

• After design-package, decompose-features, and initial-estimate (features have readyForDev intent).
• Immediately before emitting architect.developer.handoff.
• Re-issue when ADR set or contracts change mid-flight.

Do not use as a substitute for the design package; the slice points into it.

Inputs

Output path

Default:

design/<workPackageId>/context-slice.md

This path becomes contextSlicePath on architect.developer.handoff.

Steps

1. Collect applicable set

From design package + feature scope, select:

• ADR ids whose rules bind implementers for this WP.
• Contract paths that will be coded against.
• NFR budgets that must be measured or respected in this WP.

Exclude ADRs/contracts that do not constrain this WP — list them under out-of-slice, do not silently omit a binding one.

1. Must-read paths

Bullet list of repo-relative files/dirs Developer should open first (modules, existing patterns). Prefer ≤15 entries. Mark each required or background.

1. Write `context-slice.md` with required sections:

```markdown

workPackageId: <id> designPackagePath: design/<id>/ decisionIds: [ADR-...] generated: YYYY-MM-DD

# Context slice — <workPackageId>

## In slice ### Decisions

### Contracts

### NFR budgets

### Must-read

• path — required|background — why

## Out of slice Explicit list: what Developer must not reinterpret or expand without Architect (other platforms, deferred ADRs, future epics).

## Non-negotiables Bullets copied/shortened from ADR rules that would otherwise be missed.

## Open items Only human-acknowledged residual opens; else empty. ```

1. Boundary check

Every accepted ADR that decisions.md marks as applying to this WP appears under In slice. If an ADR would be omitted, either add it or AskUserQuestion to confirm omission.

1. Emit machine handoff (hard gate — do not skip)

Ensure design/<workPackageId>/change-intent.json exists (from design-package / decompose) with non-empty changes covering every requiredMachineFiles / ## Machine requirements entry (edit and create ops as needed) and features readyForDev: true. Then run:

`` node ${CLAUDE_PLUGIN_ROOT}/tools/emit-developer-handoff.mjs \ --ba-handoff wp/<workPackageId>/handoffs/ba-architect.handoff.json \ --design-dir design/<workPackageId> \ --out design \ --product <product-root> ``

(Paths may be absolute; --canon + --wp may replace --ba-handoff.)

This writes both:

• design/<workPackageId>/change-spec.json
• design/<workPackageId>/architect-developer.handoff.json

with contract: "architect.developer.handoff", version, workPackageId, designPackagePath, contextSlicePath, decisionIds, and features[] with readyForDev: true.

Markdown-only packages are incomplete. Do not announce Developer handoff until both JSON files exist and the tool exits 0. Do not hand-author placeholder JSON.

1. Announce

Slice path + architect-developer.handoff.json path + decision count + any residual opens for Developer accept-work-package.

Human gates

Done when

• design/<workPackageId>/context-slice.md exists with in-slice / out-of-slice / non-negotiables.
• design/<workPackageId>/change-spec.json and architect-developer.handoff.json exist (from emit-developer-handoff).
• decisionIds on the handoff match the slice.
• Out-of-slice boundaries are explicit (not “see architecture/”).
• Package is ready for Developer accept-work-package.

Failure modes