---
id: MAN-18
family: GR-MAN
level: extended
profiles: [storage-api]
posture: normative-target
added: "1.0"
changed: "1.0"
source: https://flowdrop.io/spec/rules/gr-man/man-18
specification: FlowDrop Workflow Specification 1.0-draft
licence: CC BY 4.0
---

# MAN-18 — The contract is rebuilt when the manifest changes, and versioned when it is

*GR-MAN (Part I) · level: extended · profiles: storage-api · added in 1.0*

Rebuilding is triggered by the manifest, not by the schemas underneath it, so a caller reads a contract that was published deliberately rather than one that drifts.

## The rule

> **Normative.** This is the rule.
>
> 1. A workflow's contract is rebuilt when its declared input or output manifest differs from the stored one, or when a rebuild is forced.
>
> 2. A change inside a bound port's own schema does not trigger a rebuild, so the published contract stays as it was until something else rebuilds it.
>
> 3. A side with no declared entries stores no schema for that side.
>
> 4. On rebuild the contract version is bumped: from an all-zero version any of a major, minor or patch bump yields the first released version; otherwise the named digit is incremented and the lower digits reset.
>
> 5. A rebuild that bumps nothing writes the schemas and leaves the version untouched.
>
> 6. A build that fails logs an error, preserves the previously published contract, and does not prevent the workflow from being saved.


## What it means

The trigger is the port list, not what changed underneath it. A bound port's
own schema can change entirely — a fragment's `type`, its `minLength`,
anything a node type declares — and the published contract does not move,
because nothing rebuilds it until the input or output port list itself
differs from the one already stored, or a rebuild is forced. A caller
reading the published contract is reading what was last published, not a
live reflection of the ports it names.

A side with no declared entries stores no schema for that side at all —
there is nothing to build. And a build that fails leaves the previously
published contract in place: the workflow still saves, the failure is
recorded, and nothing about the failed rebuild reaches the caller.

## Example

```json title="An input port list identical to the one already published" verdict="skipped"
[ { "name": "in", "node_id": "n1", "port": "p1" } ]
```

```json title="A workflow declaring no output ports at all"
[ ]
```

```json title="What is stored for that side" verdict="none"
null
```

## Related rules

- Names: MAN-5, MAN-21
- Referenced by: MAN-21, STORE-8

---

Rule identifiers are permanent and are never renumbered. This specification carries
no implementation status: each implementation publishes its own standing against
these rules. Licensed CC BY 4.0.