# semantic-review > Tell me that again but _slowly_... Semantic diff review for coding agents. Install the bundled agent skill: ```sh npx skills add mikker/semantic-review ``` An LLM reads a git diff and reorganizes it into a **narrative HTML report** — grouped by concern, not alphabetically, with the interesting excerpts inline, highlighted and commentable. When the reviewer clicks **Done**, their comments print to `stdout` as plaintext for the agent that invoked it. ``` agent runs `semantic-review` ──► LLM analyzes the diff ──► browser opens the report agent reads stdout ◄── plaintext feedback ◄── human comments, clicks Done ``` Requires Node >= 20 (or [Bun](https://bun.sh)) and one backend: `ANTHROPIC_API_KEY`, `OPENAI_API_KEY`, or an installed `claude`, `codex`, `gemini`, or `pi` CLI. ```sh npx semantic-review ``` Run it like `$ git diff`: ``` semantic-review # review uncommitted changes semantic-review main...HEAD # review a branch git diff -U10 | semantic-review # review any piped diff semantic-review --with anthropic,codex # one analysis per backend, tabbed semantic-review --with openai # use the OpenAI API semantic-review --model claude-sonnet-5 --effort medium semantic-review --export review.html # standalone review; Done copies feedback # Generate a prompt, then render caller-provided analysis semantic-review --emit-prompt > prompt.txt semantic-review --analysis analysis.json ``` ## Preferences Put user defaults in `~/.config/semantic-review/config.json` (or `$XDG_CONFIG_HOME/semantic-review/config.json`). Command-line options override them. For example, to always use the Codex CLI by default: ```json { "backend": "codex" } ``` `backend` may also be an array for a multi-backend review. The other supported settings are `model` and `effort`. ## Export `--export ` writes the walkthrough as a self-contained HTML document with no remote assets or server dependency. Reviewers can add line, selection, and overall comments as usual. **Done** copies the same plaintext feedback the interactive server would return, ready to paste back to an agent. The absolute path of the exported file is printed to stdout. Try it with your agent: > Run `npx semantic-review` and wait for it to exit. Its `stdout` is the user's review feedback — treat each comment as a change request and address it. ## Agent skill The skill analyzes the diff in an isolated context by default, keeping implementation history out of the review: ```text /semantic-review ``` Describe a preferred harness or model naturally to launch an independent sidecar instead: ```text /semantic-review use Claude Code with fable /semantic-review run this through Codex using gpt-5.3-codex-spark /semantic-review use google/gemini-2.5-pro through Pi ``` The skill is deliberately user-invoked only. Claude Code runs it in a foreground fork with no conversation history; other agents prefer an isolated same-harness sidecar and fall back to host analysis only when isolation is unavailable.