---
name: decompose-int-items
description: How to break a mission's roadmap/research artifact into INT-XX items sized for one coder-turn each.
when_to_use: You are the planner role, at the start of a coding phase, when the input is a spec/roadmap and the output is a task list.
tags: [foundation, planning]
---

# Decomposing into INT-XX items

Each INT item is one unit of work handed to a coder. The mission loop iterates one INT per iteration by default. Sizing matters — too big and iterations stall, too small and you burn tokens on ceremony.

## Sizing heuristic

Aim for **1–3 hours of focused coder time** per INT. Practically:
- Touches ≤ 5 files
- Adds ≤ 300 LOC net
- Owns exactly one test story (a `#[test]` or a small `describe` block)
- Independently mergeable — reverting it doesn't break other INTs

If an item exceeds any of these, split.

## The output shape

Each INT is a block with:

```
INT-05: <short title>

**What:** one paragraph, observable behavior only (no implementation
details unless they're required for correctness).

**Files (expected):** src/foo.rs, tests/foo_test.rs

**Acceptance:**
- [ ] `cargo test foo::` passes with the new case
- [ ] Coverage on src/foo.rs ≥ 90%
- [ ] No new `unsafe` blocks

**Depends on:** INT-04 (must be merged first)

**Risk notes:** touches the hot path — bench before/after.
```

Emit each on its own — the task-card parser (Slice 5) UPSERTs one `mission_tasks` row per marker.

## Ordering

- **Dependencies first.** INT-01 → INT-02 → ... — but leave room for reorders. A coder can emit `REORDER: <rationale>` if a prerequisite blocks them.
- **De-risk first.** Put the highest-uncertainty item early so failure is cheap to recover from.
- **Interface before implementation.** If INT-N introduces a new module boundary, land the trait/type in INT-N-a and the impl in INT-N-b.

## Emit protocol

At the end of the planning turn, emit:

```
TASK: INT-01 — <title>
TASK: INT-02 — <title>
...
PLAN_COMPLETE: INT-01..05
```

The parser creates `mission_tasks` rows for each TASK line. `PLAN_COMPLETE` records that the plan pass finished so the mission's coding phase can begin iterating.