REST API

Start the REST server with:

graphwalker online -s RESTFUL -p 8080 -m model.json "random(edge_coverage(100))"

All endpoints are under the /graphwalker path prefix.

Response format

Successful responses include "result": "ok". Errors include "result": "nok" with an "error" message.

---

POST /graphwalker/load

Load a model and initialize the execution engine.

Request body: JSON model definition (the full model file content).

Response:

{
  "result": "ok",
  "seed": 7298345612
}

The returned seed can be used later to reproduce the same traversal.

Error example:

{
  "result": "nok",
  "error": "Model has no generator specified"
}

---

GET /graphwalker/hasNext

Check whether more steps are available.

Response:

{
  "result": "ok",
  "hasNext": "true"
}

Returns "false" when the stop condition is fulfilled.

Error (no model loaded):

{
  "result": "nok",
  "error": "No model(s) are loaded."
}

---

GET /graphwalker/getNext

Advance to the next element and return it.

Response:

{
  "result": "ok",
  "currentElementName": "e_Login",
  "currentElementID": "e1",
  "modelId": "853429e2-0528-48b9-97b3-7725eafbb8b5"
}

Field	Description
currentElementName	Name of the current element (vertex or edge)
currentElementID	ID of the current element
modelId	ID of the model containing the element

---

GET /graphwalker/getData

Get the current execution data (all variables).

Response:

{
  "result": "ok",
  "data": "loggedIn=true; itemCount=3"
}

The data field is a string representation of all variables in the execution context.

---

PUT /graphwalker/setData/{script}

Execute a script to modify execution data. The script is passed as a URL path parameter.

Example request:

PUT /graphwalker/setData/loggedIn%20%3D%20true%3B

(URL-decoded: loggedIn = true;)

Response:

{
  "result": "ok"
}

---

PUT /graphwalker/restart

Reset execution to the initial state. The model remains loaded but all visit counts, variables, and state are cleared.

Response:

{
  "result": "ok"
}

---

GET /graphwalker/getStatistics

Get coverage statistics for the current execution.

Response:

{
  "result": "ok",
  "totalNumberOfVertices": 5,
  "totalNumberOfEdges": 8,
  "totalNumberOfVisitedVertices": 3,
  "totalNumberOfVisitedEdges": 6,
  "totalNumberOfUnvisitedVertices": 2,
  "totalNumberOfUnvisitedEdges": 2,
  "vertexCoverage": 60,
  "edgeCoverage": 75
}

Field	Description
totalNumberOfVertices	Total vertices in all models
totalNumberOfEdges	Total edges in all models
totalNumberOfVisitedVertices	Vertices visited at least once
totalNumberOfVisitedEdges	Edges visited at least once
totalNumberOfUnvisitedVertices	Vertices not yet visited
totalNumberOfUnvisitedEdges	Edges not yet visited
vertexCoverage	Percentage of vertices visited (0–100)
edgeCoverage	Percentage of edges visited (0–100)

---

Typical usage pattern

# 1. Load a model (or start the server with -m flag to pre-load)
curl -X POST http://localhost:8080/graphwalker/load -d @model.json

# 2. Loop: check and step
while curl -s http://localhost:8080/graphwalker/hasNext | grep -q '"true"'; do
  STEP=$(curl -s http://localhost:8080/graphwalker/getNext)
  echo "$STEP"
  # Execute the test step indicated by currentElementName
done

# 3. Check final coverage
curl -s http://localhost:8080/graphwalker/getStatistics

---

Seed and determinism

When starting with --seed <value>, the same seed produces identical traversal paths. The seed is also returned by the /load endpoint, so you can capture it and replay later:

# Capture the seed
SEED=$(curl -s -X POST http://localhost:8080/graphwalker/load -d @model.json | jq -r '.seed')
echo "Seed: $SEED"

# Replay with the same seed later
graphwalker online -s RESTFUL --seed $SEED -m model.json "random(edge_coverage(100))"