# Schedule ready nodes

`schedule-ready-nodes` · version 1.0.0 · Graphs & scheduling · free, no key needed

List DAG nodes that can start because they are not completed and every predecessor is completed.

**Use when you need to: schedule ready nodes · ready nodes given completed set · which dependency nodes can start.**

## Supported

- schedule ready nodes
- ready nodes given completed set
- which dependency nodes can start

## Not supported

- resource and capacity constraints
- running versus completed distinction
- ALAP layers
- calendar dates and working hours

## Behavior

- Input is a directed simple graph plus completed, a list of unique existing node ids that may be empty.
- Edge from→to means from is a prerequisite of to and must complete before to starts.
- The graph must be a DAG; a cycle including a self-loop throws invalid_input with a message containing cycle.
- A node is ready if and only if it is not in completed and every predecessor is in completed.
- Output ready lists those node ids in declared nodes array order.
- An empty graph with empty completed yields ready [].

## Input

- `nodes` (array of string, required): max items 2000; each min length 1; each max length 256
- `edges` (array of object, required): max items 10000
- `completed` (array of string, required): max items 2000; each min length 1; each max length 256

## Output

- `ready` (array of string, required): max items 2000; each min length 1; each max length 256

## Limits

- max nodes: 2000
- max edges: 10000
- max node id bytes: 256
- max completed: 2000

## Example

Request input:

```json
{
  "nodes": [
    "fetch",
    "compile",
    "lint",
    "link"
  ],
  "edges": [
    {
      "from": "fetch",
      "to": "compile"
    },
    {
      "from": "fetch",
      "to": "lint"
    },
    {
      "from": "compile",
      "to": "link"
    },
    {
      "from": "lint",
      "to": "link"
    }
  ],
  "completed": [
    "fetch"
  ]
}
```

Response:

```json
{
  "result": {
    "ready": [
      "compile",
      "lint"
    ]
  }
}
```

## How to call it

### MCP

Connect `https://computefirst.net/mcp` ([setup](/docs#connect)), then call `execute` with:

```json
{
  "id": "schedule-ready-nodes",
  "version": "1.0.0",
  "input": {
    "nodes": [
      "fetch",
      "compile",
      "lint",
      "link"
    ],
    "edges": [
      {
        "from": "fetch",
        "to": "compile"
      },
      {
        "from": "fetch",
        "to": "lint"
      },
      {
        "from": "compile",
        "to": "link"
      },
      {
        "from": "lint",
        "to": "link"
      }
    ],
    "completed": [
      "fetch"
    ]
  }
}
```

### HTTP (no key)

```sh
curl -X POST https://computefirst.net/v1/tools/schedule-ready-nodes/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"nodes":["fetch","compile","lint","link"],"edges":[{"from":"fetch","to":"compile"},{"from":"fetch","to":"lint"},{"from":"compile","to":"link"},{"from":"lint","to":"link"}],"completed":["fetch"]}'
```

The machine-readable contract is at [/v1/tools/schedule-ready-nodes/versions/1.0.0](/v1/tools/schedule-ready-nodes/versions/1.0.0).

### CLI

```sh
node cli.mjs run schedule-ready-nodes 1.0.0 --input input.json --base-url https://computefirst.net
```

Get the client at [/clients/cli/](/clients/cli/).

## Related tools

- [Graph dependency impact](/tools/graph-dependency-impact): List nodes downstream of a removed set: not themselves removed, reachable by a directed path of length at least 1.
- [Schedule critical path](/tools/schedule-critical-path): Compute CPM zero-slack critical nodes and tight edges on a DAG, plus one representative critical path.
- [Schedule earliest finish](/tools/schedule-earliest-finish): Compute CPM earliest start and earliest finish times for a DAG with node durations, plus the project makespan.
- [Graph ancestors](/tools/graph-ancestors): List every ancestor of given targets, including the targets, in reverse-graph BFS discovery order.
- [Graph induced subgraph](/tools/graph-induced-subgraph): Return the vertex-induced subgraph on a listed node subset, preserving declared node and edge order.
- [Graph reachable from](/tools/graph-reachable-from): List nodes reachable from given sources by directed BFS, in discovery order.