# `generate-spec` The `generate-spec` command infers an OpenAPI description from recorded HTTP traffic. The command reads a traffic log (or a folder of logs), builds a deterministic baseline description from the observed exchanges, and can optionally refine that baseline with an AI provider. Experimental This is an experimental feature. Its behavior, command, flags, and output may change in future releases. The `generate-spec` command generates OpenAPI 3.1 descriptions only. ## Supported traffic formats The traffic input can be provided in any of the following formats. By default the format is detected automatically from the file contents: - HAR - Kong - Nginx JSON - Apache JSON - NDJSON Traffic parsing is shared with the [`drift`](/docs/cli/commands/drift) command, so any log that works with `drift` works here too. ## How it works The baseline description is inferred directly from the recorded exchanges: identifier-like path segments become named path parameters, request and response schemas are merged across all observations, repeated object shapes are extracted into `components/schemas`, and consistently formatted string values get `format` or `enum` hints. A description inferred from traffic alone is a hypothesis: types are coarse and there are no descriptions, enums, or examples beyond what was observed. With `--with-ai`, the command sends each operation together with sample exchanges to an AI provider, which narrows types and adds formats, enums, descriptions, and examples. The AI's answer is never trusted blindly: a refined operation is only accepted when it keeps the operation's path, method, and observed response status codes, and passes validation with the `spec` ruleset. Rejected refinements keep their baseline version, and if refinement fails entirely the command falls back to the baseline description. The validation uses the built-in `spec` ruleset, not your project's `redocly.yaml` — lint the generated description with your own configuration afterward. Data sharing `--with-ai` sends samples of the recorded traffic (URLs, query strings, request and response bodies) to the selected AI provider. Make sure the traffic contains no secrets or personal data you are not allowed to share. ### AI providers Refinement runs a locally installed AI CLI in non-interactive mode: `claude` (Claude Code), `codex` (Codex CLI), or `cursor` (Cursor CLI). The selected CLI must be installed and authenticated on the machine running the command. The provider runs in isolation: project context the CLIs normally load (such as `CLAUDE.md`, `AGENTS.md`, or `.cursor/rules`) and settings like a configured model do not apply. Use `--ai-model` to choose a model, or the provider's default is used. ## Usage ```bash redocly generate-spec redocly generate-spec [--traffic-format=