# Run Atlas Headless in CI for Actix Web Projects in 2026 > Actix Web developers can run Atlas headless in CI using `atlas run --format json` to automate code tasks and integrate with `cargo test` and `rustfmt`. To run an Atlas session non-interactively in a CI pipeline and retrieve machine-readable output for your Actix Web project, use the `atlas run --format json` command. This approach allows Atlas to integrate direct with your existing `cargo` build and `cargo test (actix_web::test)` workflows, providing automated code generation and refactoring that respects `rustfmt` standards, all without requiring human interaction in 2026. ## Key takeaways - Run Atlas headless in Actix Web CI using `atlas run --format json` for machine-readable output. - Pre-approve Atlas tools like `bash` and `edit` in permission config for uninterrupted Actix Web automation. - Atlas integrates with `cargo test (actix_web::test)` and `rustfmt` to maintain Actix Web code quality. - Manage iterative Actix Web tasks in CI with Atlas's `--continue` or `--session` flags. - Atlas provides unified diffs for every file edit, offering transparency for Actix Web code changes. ## How to Run Atlas Headless in Actix Web CI Pipelines Running Atlas headless in your Actix Web CI pipeline in 2026 is straightforward with `atlas run`. This command is designed for non-interactive execution, sending a single prompt and exiting when the session goes idle. It streams events to stdout, making it ideal for automated workflows that need machine-readable output. The core of running Atlas headless in an Actix Web CI environment is the `atlas run` command. When invoked, Atlas processes a given prompt, such as "inject shared state with web::Data" or "write actix_web::test integration cases," and then executes its plan. For CI, the default non-interactive mode is crucial: Atlas sends its initial prompt, performs its tasks, and then gracefully exits once the session becomes idle. This ensures that your CI job does not hang, providing a predictable execution flow. The output, by default, is human-readable prose, but for pipeline steps that require structured data, the `--format json` flag transforms the event stream into a machine-readable format, allowing subsequent CI steps to parse and react to Atlas's actions. This enables robust automation for Actix Web projects, from initial code generation to complex refactoring tasks. ## Configuring Atlas Permissions for Actix Web CI Automation For a headless Atlas run in your Actix Web CI, pre-approving necessary tools is a critical step, as there's no human to answer an `ask` prompt. Atlas's permission configuration allows you to set `allow`, `ask`, or `deny` rules for tools like `bash`, `read`, `edit`, and `todowrite` before any execution in 2026. In a headless CI environment, Atlas cannot prompt a user for permission to execute a tool. Therefore, for Actix Web projects, you must pre-approve the tools Atlas needs to perform its job. This is managed through Atlas's permission configuration, which allows you to define explicit `allow`, `ask`, or `deny` rules for each tool. For typical Actix Web development tasks, Atlas might need `read` to understand your `Cargo.toml` and handler signatures, `edit` to modify source files like `src/main.rs` or `src/lib.rs`, `bash` to run `cargo test (actix_web::test)` or `rustfmt`, and `todowrite` for specific task management. By setting these permissions to `allow` in your CI configuration, you ensure that Atlas can proceed with its plan without interruption, such as injecting `web::Data` into your application or writing new `actix_web::test` integration cases. This proactive permission management is essential for reliable, automated Actix Web code generation and refactoring in a CI pipeline. ## Integrating Atlas Output with Actix Web Test and Build Steps Integrating Atlas's machine-readable output with your Actix Web CI pipeline involves using the `--format json` flag, which streams raw events to stdout. This allows subsequent `cargo` build and `cargo test (actix_web::test)` steps to programmatically react to Atlas's actions, ensuring code quality and functionality in 2026. When Atlas runs headless in CI for an Actix Web project, the `--format json` flag is key for programmatic integration. This flag instructs Atlas to stream its internal events,such as tool calls, plan drafts, and file edits,as structured JSON objects to standard output. A subsequent CI step, written in `bash` or another scripting language, can then parse this JSON stream. For example, after Atlas has been asked to "write actix_web::test integration cases," the JSON output can confirm the files modified or the success of the `edit` tool. This allows your pipeline to trigger `cargo test (actix_web::test)` to validate the new tests, or `cargo clippy` and `rustfmt` to ensure the code adheres to Rust's best practices and formatting standards. The unified diffs Atlas computes for every file edit are also surfaced, providing a clear audit trail that can be captured and reviewed, even in an automated context. This robust integration ensures that Atlas-generated code for Actix Web is always validated against your project's quality gates. ## Managing Atlas Sessions for Actix Web Iterative Development in CI For iterative Actix Web development within CI, Atlas offers session management capabilities like `--continue`, `--session`, and `--fork`. These flags allow a pipeline step to resume a prior Atlas run or build upon its context, which is particularly useful for complex tasks that might span multiple CI jobs in 2026. While `atlas run` typically completes a single task and exits, Actix Web development often involves iterative refinement. Atlas supports this in CI through its session management flags. The `--continue` flag allows a new `atlas run` invocation to pick up exactly where a previous session left off, preserving the agent's state and context. Alternatively, `--session ` lets you explicitly specify a session to resume, which is useful if your CI system needs to manage multiple concurrent Atlas tasks. For scenarios where you want to explore an alternative path based on a previous run without altering the original session, the `--fork` flag creates a new session derived from an existing one. This is invaluable for debugging or experimenting with different approaches to, for instance, refactoring an Actix Web service or modifying `web::Data` injection logic. These capabilities ensure that even in a headless CI environment, Atlas can support complex, multi-stage Actix Web development workflows efficiently and effectively. ## Steps 1. Prepare your Actix Web project: Ensure your `Cargo.toml` includes `actix-web` as a dependency and your project structure is ready for Atlas to read. 2. Configure Atlas permissions for CI: Set `allow` rules for `bash`, `read`, `edit`, and `todowrite` in your Atlas permission configuration to enable headless execution without prompts. 3. Invoke Atlas headless with a specific prompt: Run `atlas run --format json --model github/gpt-4 --command "inject shared state with web::Data into src/main.rs"` within your CI script. 4. Parse Atlas's JSON output: Capture the stdout from the `atlas run` command and parse the JSON event stream to monitor Atlas's actions and confirm file modifications. 5. Run Actix Web tests: Execute `cargo test (actix_web::test)` to validate any new or modified integration tests written by Atlas, ensuring the Actix Web application functions correctly. 6. Format and lint Actix Web code: Apply `rustfmt` and `cargo clippy` to the codebase after Atlas edits, ensuring the generated or modified code adheres to Rust's style and best practices. 7. Review and commit changes: Capture the unified diffs generated by Atlas, review them programmatically or manually, and then stage and create a commit using `git` if changes are approved. ## FAQ ### How do I ensure Atlas doesn't prompt for input during an Actix Web CI run? To prevent Atlas from prompting for input in an Actix Web CI pipeline, you must pre-approve all necessary tools (like `bash`, `read`, `edit`) in your Atlas permission configuration with `allow` rules. ### Can Atlas generate `actix_web::test` integration tests in CI? Yes, Atlas can write `actix_web::test` integration cases in CI. You can prompt it to do so, and then run `cargo test (actix_web::test)` as a subsequent pipeline step to validate the new tests. ### How can I get structured output from Atlas for my Actix Web CI pipeline? Use the `--format json` flag with `atlas run`. This streams raw event data as JSON to stdout, allowing your Actix Web CI pipeline to parse and react programmatically. ### What Actix Web-specific tasks can Atlas automate in CI? Atlas can automate tasks like injecting shared state with `web::Data`, reading `App` builder configurations, registering services and routes, and fixing `Arc` clones, all within your Actix Web project. ### How does Atlas handle code formatting for Actix Web projects in CI? After Atlas makes edits, you can configure your CI pipeline to run `rustfmt` as a separate step. Atlas can also be prompted to run `rustfmt` itself, provided the `bash` tool is allowed. ### Can Atlas resume a previous session in an Actix Web CI job? Yes, Atlas supports resuming previous sessions in CI using the `--continue` or `--session ` flags, allowing iterative development or debugging of Actix Web tasks across pipeline runs. ### How does Atlas ensure code safety when modifying Actix Web files in CI? Atlas computes a unified diff for every file edit and surfaces it. While headless, these diffs can be captured from the `--format json` output for programmatic review or logging, and changes are permission-gated. --- Canonical HTML: https://runatlas.sh/resources/stacks/run-atlas-headless-in-ci-in-actix Source of truth: aeo_pages row `/resources/stacks/run-atlas-headless-in-ci-in-actix` (segment: Stacks) (this file is generated from it, never hand-edited). Licence: Atlas is proprietary with a free core. It is not open source and there is no public source repository.