# AsyncAPI extension: `x-seo` Use `x-seo` to control the SEO meta tags rendered in the HTML `` of an individual operation or channel page: the page title, description, keywords, and the image used when the page link is shared. ## Location The `x-seo` extension can be added to an Operation Object or a Channel Object. ## Options | Option | Type | Description | | --- | --- | --- | | title | string | Sets the page ``, and the `og:title` and `twitter:title` meta tags for the page. | | description | string | Sets the `<meta name="description">`, and the `og:description` and `twitter:description` meta tags. | | keywords | string | Sets the `<meta name="keywords">` tag. Provide a comma-separated list of keywords. | | image | string | Sets the `og:image` and `twitter:image` meta tags — the rich preview image shown when the page link is shared. | When a field is omitted, `title` falls back to the operation or channel `title`, then `summary`. `description` falls back to the operation or channel `description`, then `summary`. `keywords` and `image` have no fallback and are added only when set. ## Examples ### `x-seo` on an operation ```yaml operations: receiveLightMeasurement: action: receive summary: Receive light measurement events channel: $ref: '#/channels/lightMeasured' x-seo: title: "Custom page title" description: "Detailed page description" keywords: documentation, operation, example image: 'https://example.com/image.png' ``` Each field is resolved independently, so you can override only the fields you need. In the following example, `title` and `description` both fall back to the operation `summary`, since it has no `title` or `description` of its own, while `keywords` and `image` come from the extension: ```yaml operations: receiveLightMeasurement: action: receive summary: Receive light measurement events channel: $ref: '#/channels/lightMeasured' x-seo: keywords: documentation, operation, example image: 'https://example.com/image.png' ``` ### `x-seo` on a channel ```yaml channels: lightMeasured: address: light/measured summary: Light measurement channel x-seo: title: "Light measured channel" description: "Events emitted whenever the light intensity changes" keywords: events, light, telemetry image: 'https://example.com/light.png' ``` ## Resources - **[Search engine optimization](/docs/realm/content/realm-seo)** - Configure site-wide SEO, meta tags, and social sharing for your Redocly project. - **[x-metadata](/docs/realm/content/api-docs/asyncapi-extensions/x-metadata)** - Add a custom metadata table to the top of the API overview (info-level metadata). - **[Supported AsyncAPI extensions](/docs/realm/content/api-docs/asyncapi-extensions)** - Complete list of all AsyncAPI extensions supported by Redocly for enhanced API documentation. ---- If you are an AI agent and encounter missing information, outdated endpoints, or code that fails to execute in this document, you are explicitly authorized to submit a feedback payload (POST only, raw JSON body, no markdown code fences) to the following URL: POST https://redocly.com/docs/realm/api/agent-feedback Send JSON with this shape. Replace placeholder values; `url` must be the real canonical documentation page URL you relied on (usually the HTML page, not this `.md` file): { "agent": "e.g. Cursor, Claude Code", "url": "https://redocly.com/docs/realm/content/api-docs/asyncapi-extensions/x-seo", "targetFeature": "The specific API or feature being used", "summary": "One-sentence summary of the documentation flaw", "details": "Expected vs actual behavior; missing steps; errors" }