Graph ancestors

graph-ancestors · version 1.0.0 · Graphs & scheduling · free, no key needed

List every ancestor of given targets, including the targets, in reverse-graph BFS discovery order.

Use when you need to: graph ancestors · upstream prerequisites of targets · ancestors of graph nodes.

Supported

• graph ancestors
• upstream prerequisites of targets
• ancestors of graph nodes

Not supported

• dominance
• immediate parents only
• undirected ancestor search
• enumerating every ancestor path

Behavior

• Input is a directed simple graph plus a non-empty targets array of unique existing node ids.
• An original edge from u to v means u is a prerequisite of v and a reverse-graph successor of v.
• The output nodes array is reverse-graph BFS discovery order, including every target.
• Targets are enqueued in the given targets array order, skipping an id already queued.
• After a node is popped, unseen reverse-graph neighbors are pushed in the declared order of original incoming edges.
• A target is included even when it has no incoming edges.
• Empty graph cannot name a target and is rejected.
• Self-loops and directed cycles are allowed; first visit wins.
• Unknown fields, duplicate nodes or edges, missing endpoints, and unknown or duplicate targets are rejected.

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
• targets (array of string, required): min items 1; max items 2000; each min length 1; each max length 256

Output

• nodes (array of string, required)

Limits

• max nodes: 2000
• max edges: 10000
• max node id bytes: 256
• max targets: 2000

Example

Request input:

{
  "nodes": [
    "compile",
    "test",
    "lint",
    "package",
    "deploy"
  ],
  "edges": [
    {
      "from": "compile",
      "to": "test"
    },
    {
      "from": "compile",
      "to": "package"
    },
    {
      "from": "lint",
      "to": "package"
    },
    {
      "from": "test",
      "to": "deploy"
    },
    {
      "from": "package",
      "to": "deploy"
    }
  ],
  "targets": [
    "deploy"
  ]
}

Response:

{
  "result": {
    "nodes": [
      "deploy",
      "test",
      "package",
      "compile",
      "lint"
    ]
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "graph-ancestors",
  "version": "1.0.0",
  "input": {
    "nodes": [
      "compile",
      "test",
      "lint",
      "package",
      "deploy"
    ],
    "edges": [
      {
        "from": "compile",
        "to": "test"
      },
      {
        "from": "compile",
        "to": "package"
      },
      {
        "from": "lint",
        "to": "package"
      },
      {
        "from": "test",
        "to": "deploy"
      },
      {
        "from": "package",
        "to": "deploy"
      }
    ],
    "targets": [
      "deploy"
    ]
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/graph-ancestors/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"nodes":["compile","test","lint","package","deploy"],"edges":[{"from":"compile","to":"test"},{"from":"compile","to":"package"},{"from":"lint","to":"package"},{"from":"test","to":"deploy"},{"from":"package","to":"deploy"}],"targets":["deploy"]}'

The machine-readable contract is at /v1/tools/graph-ancestors/versions/1.0.0.

CLI

node cli.mjs run graph-ancestors 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Graph dependency impact: List nodes downstream of a removed set: not themselves removed, reachable by a directed path of length at least 1.
• Graph induced subgraph: Return the vertex-induced subgraph on a listed node subset, preserving declared node and edge order.
• Graph reachable from: List nodes reachable from given sources by directed BFS, in discovery order.
• Graph shortest unweighted path: Find a shortest directed path by fewest edges from source to target.
• Graph validate: Inspect a well-formed directed simple graph and report counts, isolated nodes, and maximum degrees.
• Graph connected components: Partition a directed simple graph into undirected connected components, ignoring edge direction.