{"id":46843429,"url":"https://github.com/lbkulinski/cta4j-java-sdk","last_synced_at":"2026-04-15T01:04:08.681Z","repository":{"id":318730823,"uuid":"1073887747","full_name":"lbkulinski/cta4j-java-sdk","owner":"lbkulinski","description":"A lightweight Java SDK for interacting with the Chicago Transit Authority (CTA) APIs","archived":false,"fork":false,"pushed_at":"2026-03-08T20:00:55.000Z","size":462,"stargazers_count":0,"open_issues_count":3,"forks_count":0,"subscribers_count":0,"default_branch":"main","last_synced_at":"2026-03-10T19:39:55.580Z","etag":null,"topics":["chicago","cta","java","transit"],"latest_commit_sha":null,"homepage":"https://cta4j.app","language":"Java","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"apache-2.0","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/lbkulinski.png","metadata":{"files":{"readme":"README.md","changelog":"CHANGELOG.md","contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null,"zenodo":null,"notice":null,"maintainers":null,"copyright":null,"agents":null,"dco":null,"cla":null}},"created_at":"2025-10-10T19:23:42.000Z","updated_at":"2026-01-31T20:04:47.000Z","dependencies_parsed_at":"2025-10-14T10:51:01.937Z","dependency_job_id":null,"html_url":"https://github.com/lbkulinski/cta4j-java-sdk","commit_stats":null,"previous_names":["lbkulinski/cta4j-java-sdk"],"tags_count":8,"template":false,"template_full_name":null,"purl":"pkg:github/lbkulinski/cta4j-java-sdk","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/lbkulinski%2Fcta4j-java-sdk","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/lbkulinski%2Fcta4j-java-sdk/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/lbkulinski%2Fcta4j-java-sdk/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/lbkulinski%2Fcta4j-java-sdk/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/lbkulinski","download_url":"https://codeload.github.com/lbkulinski/cta4j-java-sdk/tar.gz/refs/heads/main","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/lbkulinski%2Fcta4j-java-sdk/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":31821686,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2026-04-14T18:05:02.291Z","status":"ssl_error","status_checked_at":"2026-04-14T18:05:01.765Z","response_time":153,"last_error":"SSL_read: unexpected eof while reading","robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":false,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["chicago","cta","java","transit"],"created_at":"2026-03-10T14:04:19.235Z","updated_at":"2026-04-15T01:04:08.664Z","avatar_url":"https://github.com/lbkulinski.png","language":"Java","funding_links":[],"categories":[],"sub_categories":[],"readme":"# cta4j Java SDK\n\nA lightweight Java SDK for interacting with the [Chicago Transit Authority (CTA)](https://www.transitchicago.com/) APIs — both Train Tracker and Bus Tracker.  \n\nBuilt for simplicity, reliability, and minimal external dependencies.\n\n---\n\n## 🚆 Overview\n\n`cta4j-java-sdk` provides a clean, type-safe interface for accessing CTA's public transit data.  \nIt wraps the official Train and Bus Tracker APIs with intuitive Java models and error handling.\n\n**Features:**\n- Simple, dependency-light HTTP client (uses Apache HttpClient 5)\n- DTOs modeled as Java records\n- Works with both **Train Tracker** and **Bus Tracker** APIs\n\n---\n\n## 🔑 Getting API Keys\n\nYou'll need a free API key from CTA to use the SDK.\n\n- **Train Tracker API** → [Apply here](https://www.transitchicago.com/developers/traintrackerapply/)\n- **Bus Tracker API** → [Apply here](https://www.transitchicago.com/developers/bustracker/)\n\nAfter applying, you'll receive an API key by email. Keep it safe — you'll use it when initializing the client.\n\n---\n\n## ⚙️ Installation\n\n### Maven\n```xml\n\u003cdependency\u003e\n    \u003cgroupId\u003ecom.cta4j\u003c/groupId\u003e\n    \u003cartifactId\u003ecta4j-java-sdk\u003c/artifactId\u003e\n    \u003cversion\u003e4.0.3\u003c/version\u003e\n\u003c/dependency\u003e\n```\n\n### Gradle (Kotlin DSL)\n```kotlin\nimplementation(\"com.cta4j:cta4j-java-sdk:4.0.3\")\n```\n\n---\n\n## 🧩 Example Usage\n\n### Fetch upcoming train arrivals for a station\n\n```java\nimport com.cta4j.train.TrainApi;\nimport java.time.Duration;\n\npublic final class Application {\n    public static void main(String[] args) {\n        TrainApi trainApi = TrainApi.builder(\"TRAIN_API_KEY\")\n                                    .build();\n\n        trainApi.arrivals()\n                .findByMapId(\"41320\")\n                .forEach(arrival -\u003e System.out.printf(\n                    \"%s-bound %s Line train is arriving at %s in %d minutes%n\",\n                    arrival.destinationName(),\n                    arrival.line(),\n                    arrival.stationName(),\n                    Duration.between(arrival.predictionTime(), arrival.arrivalTime())\n                            .toMinutes()\n                ));\n\n        // Example output:\n        // Loop-bound BROWN Line train is arriving at Belmont in 2 minutes\n        // Howard-bound RED Line train is arriving at Belmont in 2 minutes\n        // Howard-bound RED Line train is arriving at Belmont in 4 minutes\n        // Kimball-bound BROWN Line train is arriving at Belmont in 9 minutes\n        // 95th/Dan Ryan-bound RED Line train is arriving at Belmont in 10 minutes\n        // ...\n    }\n}\n```\n\n### Fetch upcoming bus arrivals for a stop\n\n```java\nimport com.cta4j.bus.BusApi;\nimport java.time.Duration;\nimport java.time.Instant;\n\npublic final class Application {\n    public static void main(String[] args) {\n        BusApi busApi = BusApi.builder(\"BUS_API_KEY\")\n                              .build();\n\n        busApi.predictions()\n              .findByRouteIdAndStopId(\"22\", \"1828\")\n              .forEach(prediction -\u003e System.out.printf(\n                  \"%s-bound bus is arriving at %s in %d minutes%n\",\n                  prediction.destination(),\n                  prediction.stopName(),\n                  Duration.between(Instant.now(), prediction.arrivalTime())\n                          .toMinutes()\n              ));\n\n        // Example output:\n        // Harrison-bound bus is arriving at Clark \u0026 Belmont in 1 minutes\n        // Harrison-bound bus is arriving at Clark \u0026 Belmont in 26 minutes\n    }\n}\n```\n\n---\n\n## 🧠 Design Goals\n\n- **Dependency-light**: no Spring, Feign, or Lombok\n- **Modern Java**: uses records and Apache HttpClient 5\n- **Framework-agnostic**: works in any Java 21+ project\n\n---\n\n## 🛠️ Planned Improvements\n\n- Add test coverage\n- Add support for more API endpoints, like service alerts\n- Implement caching for frequently requested data\n- Add asynchronous request support\n\nHave ideas? Feel free to open an issue or submit a PR!\n\n---\n\n## 🧾 License\n\nThis project is licensed under the [Apache License 2.0](https://www.apache.org/licenses/LICENSE-2.0).  \nCopyright © 2026 Logan Bailey Kulinski.\n\n---\n\n## 🗺️ Links\n\n- [Train Tracker API key request](https://www.transitchicago.com/developers/traintrackerapply/)\n- [Bus Tracker API key request](https://www.transitchicago.com/developers/bustracker/)\n- [CTA Developer Resources](https://www.transitchicago.com/developers/)\n- [Project Website](https://cta4j.com)\n- [Javadoc](https://javadoc.io/doc/com.cta4j/cta4j-java-sdk/latest/index.html)\n\n---\n\n*Built with ❤️ by [Logan Kulinski](https://lbku.net)*\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Flbkulinski%2Fcta4j-java-sdk","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Flbkulinski%2Fcta4j-java-sdk","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Flbkulinski%2Fcta4j-java-sdk/lists"}