Tail runtime logs for a deployed Railway service (deploymentLogs GraphQL query)

Documented steps

1. Get a Railway API token: account/workspace tokens from https://railway.com/account/tokens, or a project token from project settings.
2. POST to the GraphQL endpoint https://backboard.railway.com/graphql/v2 with Content-Type: application/json.
3. Authenticate: account/workspace/OAuth tokens use 'Authorization: Bearer <TOKEN>'; project tokens MUST use 'Project-Access-Token: <TOKEN>' header instead.
4. Get the deployment id: list deployments with query 'query deployList($input: DeploymentListInput!){ deployments(input:$input, first:10){ edges{ node{ id status createdAt }}} }' with input {projectId, serviceId, environmentId}; pick the relevant deployment.
5. Fetch runtime logs: 'query logs($deploymentId:String!, $limit:Int){ deploymentLogs(deploymentId:$deploymentId, limit:$limit){ timestamp message severity } }' with the deployment id.
6. Optionally pass filter (text substring), startDate, endDate (ISO 8601) to narrow the time range.
7. Logs go to stdout/stderr (console.log etc.) and are captured automatically.
8. For continuous tailing use the GraphQL WebSocket subscriptions (wss://backboard.railway.com/graphql/v2, deploymentLogs subscription), which is how 'railway logs' streams live output.