canonical: https://jentic.com/apis/postlight.com/postlight

# Postlight Mercury Web Parser API

Jentic publishes the only available OpenAPI specification for Mercury Web Parser API, keeping it validated and agent-ready. Mercury Parser extracts meaningful content from any web page URL, returning clean article text, titles, authors, publication dates, lead images, and excerpts. It supports output in HTML, Markdown, or plain text formats and can also parse pre-fetched HTML content directly without re-fetching the URL.

## For AI agents

Extract article content, metadata, and structured information from any web page URL. Returns clean text with author, date, title, and lead image.

## Scope

Does not handle JavaScript rendering, screenshot capture, or full-page crawling - use for static article content extraction only.

## Capabilities

- Extract article body content from any URL in HTML, Markdown, or plain text format
- Identify and return article metadata including author, publication date, and title
- Parse pre-fetched HTML content without requiring an additional network request
- Detect lead images and excerpts suitable for content previews
- Handle paginated articles and return next-page URLs for multi-page content

## Use cases

### Content Aggregation Pipeline

Build automated content aggregation feeds by extracting article text and metadata from multiple source URLs. Mercury Parser returns structured data including title, author, publication date, and clean article body, enabling agents to compile curated content digests without manual copy-pasting. Each parsed result includes word count and excerpt for filtering and prioritization.

Example prompt: Parse https://example.com/article-url and return the article title, author, word count, and content in Markdown format

### Reader Mode for Applications

Provide a distraction-free reading experience by stripping ads, navigation, and sidebars from web pages. Mercury returns only the core article content in the requested format, along with text direction detection for proper rendering of RTL languages. Integration adds reader-mode functionality to any application in minutes rather than building custom extraction logic.

Example prompt: Extract the article content from a given URL in plain text format and verify the word count exceeds 200 words

### Research and Knowledge Base Ingestion

Ingest web articles into knowledge bases or research systems by extracting structured content programmatically. Mercury returns publication dates, authors, and full article text that can be indexed, chunked for embeddings, or stored as reference material. Supports custom headers for accessing authenticated or paywalled content when credentials are available.

Example prompt: Parse a research article URL with custom headers and store the returned title, author, date_published, and content fields in a knowledge base record

### AI Agent Web Content Access

Enable AI agents to read and understand web page content through Jentic by searching for the parse operation, loading the schema, and executing against target URLs. Agents discover the parsing capability via intent search and receive structured article data without needing to handle HTML scraping logic directly. Integration through Jentic takes under an hour compared to building custom parsers.

Example prompt: Search Jentic for 'extract article content from URL', load the Mercury Parser schema, and execute a parse request against a target news article URL

## Key endpoints

| Method | Path | Description |
| --- | --- | --- |
| GET | `/parser` | Parse a web page by URL and extract content |
| POST | `/parser` | Parse pre-fetched HTML content |

## Key resources

- **Parser** — Parse web pages by URL or from pre-fetched HTML, returning structured article content and metadata

## AI readiness

This API is usable in Jentic One now. Its AI-readiness score against Jentic's framework shows where it stands today and where improvements would make it even easier for agents to use.

- **Score:** 73 / 100
- **Maturity:** AI-Aware
- **Dimensions:**
  - Foundational Compliance: 100 / 100
  - Developer Experience & Jentic Compatibility: 69 / 100
  - AI-Readiness & Agent Experience: 63 / 100
  - Agent Usability: 94 / 100
  - Security: 50 / 100
  - AI Discoverability: 88 / 100
- **View full report:** https://jentic.com/apis/postlight.com/postlight/scorecard
- **How the score is calculated:** https://docs.jentic.com/reference/api-readiness-framework/overview/
- **More about the dimensions:** https://docs.jentic.com/reference/api-readiness-framework/specification/#dimensional-model-overview

### Score it yourself

Every API in the directory is allowlisted, so you can re-score it with no key required.

- **Score your own API:** https://jentic.com/scorecard.md
- **Scoring CLI agent skill:** https://github.com/jentic/jentic-api-scorecard/blob/main/skills/jentic-api-scorecard/SKILL.md

```sh
npx @jentic/api-scorecard-cli score <openapi-url>
```

## Why Jentic

- **Setup:** Wiring the Mercury Web Parser API by hand means handling its x-api-key header and passing the target URL to the parser on every request yourself. Through Jentic you install once, import the Mercury Web Parser API from the API Directory, store the key once, and your agent calls it.
- **Permission scoping:** Mercury exposes its parser endpoint with the target URL in the query or request body, so you limit the agent to the parse operations it needs. Only the operations you add are available to it.
- **Credential handling:** Your Mercury API key is stored once, encrypted, by your own Jentic One instance and injected at execution time. It never enters the agent's prompt, logs, or context.
- **Discovery method:** Agents search Jentic by intent such as 'extract article content from a URL', and Jentic returns the matching Mercury Parser operation with its input schema so the agent calls the right endpoint without browsing the reference docs.

## Related APIs

- **Import.io Extraction API** — Web data extraction with structured output and scheduled crawling capabilities
- **SendGrid Mail API** — Email delivery for distributing extracted article content as newsletters
- **Cloudflare API** — CDN and web performance platform for fetching cached page content before parsing

## FAQ

### Why is there no official OpenAPI spec for Mercury Web Parser API?

Postlight does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call Mercury Web Parser API via structured tooling. It is validated against the live API and kept up to date. Get started with Jentic One, the self-hosted execution layer.

### What authentication does the Mercury Web Parser API use?

The Mercury Web Parser API uses an API key passed in the x-api-key HTTP header. Through Jentic, this key is stored encrypted in the credential vault and agents receive scoped access without handling raw keys directly.

### Can I extract content in Markdown format with the Mercury Web Parser API?

Yes. The parser endpoint accepts a contentType query parameter with values html, markdown, or text. Setting contentType to markdown returns the extracted article body formatted as Markdown, which is useful for knowledge base ingestion and LLM context preparation.

### What are the rate limits for the Mercury Web Parser API?

The API returns a 429 status code when rate limits are exceeded. Specific rate limit thresholds depend on your API key tier. Monitor response headers for rate limit state and implement exponential backoff when a 429 response is received.

### How do I parse a web page through the Mercury Web Parser API using Jentic?

Install the SDK with pip install jentic, then search for the intent 'extract article content from URL'. Jentic returns the Mercury Parser parseUrl operation with its input schema. Execute with a target URL and optional contentType parameter to receive structured article data including title, author, content, and word_count fields.

### Can I parse pre-fetched HTML without making Mercury fetch the URL again?

Yes. The POST /parser endpoint accepts a JSON body with url and html fields. Provide your already-fetched HTML in the html field and the original URL in the url field for link resolution. This avoids duplicate network requests when you have already retrieved the page content.

### Can I limit what my agent is allowed to do with the Mercury Web Parser API?

Yes. Because Jentic One is self-hosted, you decide which Mercury Web Parser operations your agent can reach, and only the operations you add are available to it. Mercury exposes a single parser endpoint that takes a target URL in the query string (GET /parser) or pre-fetched HTML in the request body (POST /parser), so you can grant just the parse operation your agent needs and withhold the rest. Your Mercury API key stays with your own instance and is injected at execution time, never entering the agent's prompt or context.