Plugins · Apollo Router · apollographql/skills · Skills Docs

Plugins · Apollo Router · apollographql/skills · Skills Docs

Option	Language	Use Case
Rhai Scripts	Rhai (embedded)	Simple transformations, header manipulation
Coprocessors	Any (HTTP service)	Complex logic, external service calls
Native Plugins	Rust	Maximum performance, deep integration

// main.rhai

// Called for each incoming request
fn supergraph_service(service) {
    service.map_request(|request| {
        // Modify request
        print(`Received request: ${request.uri.path}`);
    });
}

// Called for each subgraph request
fn subgraph_service(service, subgraph) {
    service.map_request(|request| {
        // Add header for specific subgraph
        if subgraph == "products" {
            request.subgraph.headers["x-products-version"] = "v2";
        }
    });
}

fn supergraph_service(service) {
    service.map_request(|request| {
        let claims = request.context["apollo_authentication::JWT::claims"];
        if claims != () {
            request.headers["x-user-id"] = claims["sub"];
        }
    });
}

fn supergraph_service(service) {
    service.map_request(|request| {
        if request.headers["x-api-key"] == () {
            throw #{
                status: 401,
                message: "API key required"
            };
        }
    });
}

coprocessor:
  url: http://localhost:8080
  
  # Router-level (full request)
  router:
    request:
      headers: true
      body: true
    response:
      headers: true
      body: false
  
  # Subgraph-level (per subgraph)
  subgraph:
    all:
      request:
        headers: true
        body: false

{
  "version": 1,
  "stage": "RouterRequest",
  "control": "continue",
  "id": "request-uuid",
  "headers": {
    "authorization": ["Bearer token"],
    "content-type": ["application/json"]
  },
  "body": "{\"query\": \"{ users { id } }\"}"
}

const express = require('express');
const app = express();
app.use(express.json());

app.post('/', (req, res) => {
  const { stage, headers, body } = req.body;
  
  // Authentication check
  if (stage === 'RouterRequest') {
    if (!headers.authorization) {
      return res.json({
        version: 1,
        stage,
        control: { break: 401 },
        body: JSON.stringify({
          errors: [{ message: 'Unauthorized' }]
        })
      });
    }
  }
  
  // Continue with optional modifications
  res.json({
    version: 1,
    stage,
    control: 'continue',
    headers: {
      'x-processed-by': ['coprocessor']
    }
  });
});

app.listen(8080);

Criteria	Rhai	Coprocessor
Latency	~1-5ms	~10-50ms (network)
Language	Rhai only	Any language
Complexity	Simple logic	Complex business logic
External calls	Not supported	Supported
Deployment	Bundled with Router	Separate service