---
id: MAN-26
family: GR-MAN
level: extended
profiles: [storage-api, runtime, editor-client]
posture: normative-target
added: "1.0"
changed: "1.0"
source: https://flowdrop.io/spec/rules/gr-man/man-26
specification: FlowDrop Workflow Specification 1.0
licence: CC BY 4.0
---

# MAN-26 — Each trigger node gives the workflow a reserved input

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

A firing reaches a run through the same mapping a caller's input does, without the author declaring anything and without the entry ever going stale.

## The rule

> **Normative.** This is the rule.
>
> 1. For each trigger node in a workflow, the workflow MUST have one reserved input.
>
> 2. Its name MUST be `event:` followed by the trigger node's identifier.
>
> 3. It MUST bind that node's `event` port (SCH-47).
>
> 4. A reserved input MUST be derived from the workflow's trigger nodes whenever it is needed.
>
> 5. A reserved input MUST NOT be stored in the workflow's manifest, and an authoring surface MUST NOT write one there.
>
> 6. A value supplied under a reserved input name MUST be delivered as MAN-11 delivers a declared input.
>
> 7. A reserved input MUST NOT be required at launch.


## What it means

A firing puts its event somewhere, and the manifest already says how a named
input reaches a port (MAN-11). Reserved inputs reuse that mapping instead of adding a
second route into a run.

They are worked out from the trigger nodes, never stored. Add a trigger and its
reserved input exists; delete it and the input is gone; copy it and the copy gets its
own. Nothing can go stale, and nothing needs repairing.

The name cannot clash with an author's input. `event:` contains a colon, which R4.a's
alphabet does not allow, so no declared input can ever carry it. A reserved input is
never required, because a run is started by at most one firing and the other triggers
simply skip (CFG-21).

## Example

A workflow with trigger nodes `on_insert` and `on_update`, and one declared input,
`article`:

```json title="The workflow's reserved inputs" verdict="derived"
[
  { "name": "event:on_insert", "node_id": "on_insert", "port": "event" },
  { "name": "event:on_update", "node_id": "on_update", "port": "event" }
]
```

```json title="The workflow's stored manifest" verdict="unchanged"
[{ "name": "article", "node_id": "run_triage", "port": "article" }]
```

## Why

Recorded under [OPEN-21](https://flowdrop.io/spec/rulings/open-21), [OPEN-25](https://flowdrop.io/spec/rulings/open-25).

## Related rules

- Names: MAN-1, MAN-11, MAN-27, SCH-47, R4.a
- Referenced by: SCH-47, MAN-27

---

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.