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C API Reference

Convert markdown links to numbered citations.

[Example](https://example.com) becomes Example[1] with [1]: <https://example.com> in the reference list. Images ![alt](url) are preserved unchanged.

Signature:

CbergCitationResult* cberg_generate_citations(const char* markdown);

Example:

CbergCitationResult *result = cberg_generate_citations("value");

Parameters:

Name Type Required Description
markdown const char* Yes The markdown

Returns: CbergCitationResult


Create a new crawl engine with the given configuration.

If config is NULL, uses CrawlConfig.default(). Returns an error if the configuration is invalid.

Signature:

CbergCrawlEngineHandle* cberg_create_engine(CbergCrawlConfig config);

Example:

CbergCrawlEngineHandle *result = cberg_create_engine(NULL);

Parameters:

Name Type Required Description
config CbergCrawlConfig* No The configuration options

Returns: CbergCrawlEngineHandle

Errors: Returns NULL on error.


Scrape a single URL, returning extracted page data.

Signature:

CbergScrapeResult* cberg_scrape(CbergCrawlEngineHandle engine, const char* url);

Example:

CbergScrapeResult *result = cberg_scrape(NULL, "value");

Parameters:

Name Type Required Description
engine CbergCrawlEngineHandle Yes The crawl engine handle
url const char* Yes The URL to fetch

Returns: CbergScrapeResult

Errors: Returns NULL on error.


Crawl a website starting from url, following links up to the configured depth.

Signature:

CbergCrawlResult* cberg_crawl(CbergCrawlEngineHandle engine, const char* url);

Example:

CbergCrawlResult *result = cberg_crawl(NULL, "value");

Parameters:

Name Type Required Description
engine CbergCrawlEngineHandle Yes The crawl engine handle
url const char* Yes The URL to fetch

Returns: CbergCrawlResult

Errors: Returns NULL on error.


Discover all pages on a website by following links and sitemaps.

Signature:

CbergMapResult* cberg_map_urls(CbergCrawlEngineHandle engine, const char* url);

Example:

CbergMapResult *result = cberg_map_urls(NULL, "value");

Parameters:

Name Type Required Description
engine CbergCrawlEngineHandle Yes The crawl engine handle
url const char* Yes The URL to fetch

Returns: CbergMapResult

Errors: Returns NULL on error.


Execute browser actions on a single page.

Signature:

CbergInteractionResult* cberg_interact(CbergCrawlEngineHandle engine, const char* url, CbergPageAction* actions);

Example:

CbergInteractionResult *result = cberg_interact(NULL, "value", NULL);

Parameters:

Name Type Required Description
engine CbergCrawlEngineHandle Yes The crawl engine handle
url const char* Yes The URL to fetch
actions CbergPageAction* Yes The actions

Returns: CbergInteractionResult

Errors: Returns NULL on error.


Scrape multiple URLs concurrently.

Signature:

CbergBatchScrapeResults* cberg_batch_scrape(CbergCrawlEngineHandle engine, const char** urls);

Example:

CbergBatchScrapeResults *result = cberg_batch_scrape(NULL, NULL);

Parameters:

Name Type Required Description
engine CbergCrawlEngineHandle Yes The crawl engine handle
urls const char** Yes The urls

Returns: CbergBatchScrapeResults

Errors: Returns NULL on error.


Crawl multiple seed URLs concurrently, each following links to configured depth.

Signature:

CbergBatchCrawlResults* cberg_batch_crawl(CbergCrawlEngineHandle engine, const char** urls);

Example:

CbergBatchCrawlResults *result = cberg_batch_crawl(NULL, NULL);

Parameters:

Name Type Required Description
engine CbergCrawlEngineHandle Yes The crawl engine handle
urls const char** Yes The urls

Returns: CbergBatchCrawlResults

Errors: Returns NULL on error.


Result from a single page action execution.

Field Type Default Description
action_index uintptr_t Zero-based index of the action in the sequence.
action_type const char* The type of action that was executed.
success bool Whether the action completed successfully.
data void** NULL Action-specific return data (screenshot bytes, JS return value, scraped HTML).
error const char** NULL Error message if the action failed.

Article metadata extracted from article:* Open Graph tags.

Field Type Default Description
published_time const char** NULL The article publication time.
modified_time const char** NULL The article modification time.
author const char** NULL The article author.
section const char** NULL The article section.
tags const char** NULL The article tags.

Result from a single URL in a batch crawl operation.

Field Type Default Description
url const char* The seed URL that was crawled.
result CbergCrawlResult* NULL The crawl result, if successful.
error const char** NULL The error message, if the crawl failed.

Aggregate result of a batch crawl, exposing per-URL results plus precomputed counts.

The counts are derived once at construction so every binding language can read them as plain integer fields without re-iterating the results vector.

Field Type Default Description
results CbergBatchCrawlResult* NULL Per-URL crawl results, in the order seed URLs were submitted.
total_count uintptr_t Total number of seed URLs in the batch (equal to results.len()).
completed_count uintptr_t Number of seed URLs whose crawl succeeded (error is NULL).
failed_count uintptr_t Number of seed URLs whose crawl failed (error is Some).

Request to begin a multi-URL streaming crawl.

Wraps a set of seed URLs for delivery through the streaming-adapter binding surface. Required as a struct because alef’s streaming adapter requires a named request type — primitives are not supported.

Field Type Default Description
urls const char** NULL The seed URLs to crawl. Each URL is followed independently up to the engine’s configured depth.

Result from a single URL in a batch scrape operation.

Field Type Default Description
url const char* The URL that was scraped.
result CbergScrapeResult* NULL The scrape result, if successful.
error const char** NULL The error message, if the scrape failed.

Aggregate result of a batch scrape, exposing per-URL results plus precomputed counts.

The counts are derived once at construction so every binding language can read them as plain integer fields without re-iterating the results vector.

Field Type Default Description
results CbergBatchScrapeResult* NULL Per-URL scrape results, in the order URLs were submitted.
total_count uintptr_t Total number of URLs in the batch (equal to results.len()).
completed_count uintptr_t Number of URLs whose scrape succeeded (error is NULL).
failed_count uintptr_t Number of URLs whose scrape failed (error is Some).

Browser fallback configuration.

Field Type Default Description
mode CbergBrowserMode CBERG_CBERG_AUTO When to use the headless browser fallback.
backend CbergBrowserBackend CBERG_CBERG_CHROMIUMOXIDE Browser backend used to render JavaScript-heavy pages.
endpoint const char** NULL CDP WebSocket endpoint for connecting to an external browser instance.
timeout uint64_t 30000ms Timeout for browser page load and rendering (in milliseconds when serialized).
wait CbergBrowserWait CBERG_CBERG_NETWORK_IDLE Wait strategy after browser navigation.
wait_selector const char** NULL CSS selector to wait for when wait is Selector.
extra_wait uint64_t* NULL Extra time to wait after the wait condition is met.
proxy CbergProxyConfig* NULL Proxy for browser fetches. Overrides CrawlConfig.proxy when set. Native backend supports http/https only (no SOCKS5).
block_url_patterns const char** NULL URL patterns to block before the network request fires. Supports * wildcards. Useful for skipping ads/analytics/large images. Honored by BrowserBackend.Native; chromiumoxide ignores this field today.
eval_script const char** NULL JavaScript snippet evaluated after navigation completes. Scraping captures the native backend result in ScrapeResult.browser.eval_result. Interactions run this script before page actions on both browser backends but do not include the script result in InteractionResult.
robots_user_agent const char** NULL User-agent used when fetching robots.txt. Defaults to BrowserConfig.user_agent (or crawlberg’s default) if unset. Native only.
capture_network_events bool false Capture the full network event stream into the result. Default false (only the document event is captured). Native only.
session_affinity bool true Enable session affinity: reuse chromiumoxide Pages for same-domain requests so cookies + fingerprint + solved challenges persist. Default: true. When false, each request gets a fresh Page.

Signature:

CbergBrowserConfig cberg_default();

Example:

CbergBrowserConfig *result = cberg_default();

Returns: CbergBrowserConfig


Browser-specific extras populated when the native browser backend was used.

Available on ScrapeResult.browser when BrowserBackend.Native handled the request.

Field Type Default Description
eval_result void** NULL Return value of BrowserConfig.eval_script, if provided.
network_events CbergResponseMeta* NULL Network events captured during page navigation (only populated when BrowserConfig.capture_network_events is true).
cookies CbergCookieInfo* NULL All non-expired cookies present in the browser’s cookie jar after navigation completes (includes both prior cookies and server Set-Cookie).

A single numbered reference in a citation list — produced by the citation extractor when content uses inline [N]-style markers.

Field Type Default Description
index uintptr_t 1-based reference number as it appears in the source text.
url const char* Resolved absolute URL for this reference.
text const char* Human-readable anchor text or title for the reference.

Result of citation conversion.

Field Type Default Description
content const char* Markdown with links replaced by numbered citations.
references CbergCitationReference* NULL Numbered reference list: (index, url, text).

Content extraction and conversion configuration.

Controls how HTML is converted to the output format. Uses html-to-markdown-rs as the conversion engine for all formats (markdown, plain text, djot).

Field Type Default Description
output_format const char* "markdown" Output format: "markdown" (default), "plain", "djot".
preprocessing_preset const char* "standard" Preprocessing aggressiveness: "minimal", "standard" (default), "aggressive". - Minimal: only scripts/styles removed. - Standard: also removes nav, nav-hinted headers/footers/asides, forms. - Aggressive: removes all footers/asides unconditionally.
remove_navigation bool true Remove navigation elements (nav, breadcrumbs, menus). Default: true.
remove_forms bool true Remove form elements. Default: true.
strip_tags const char** NULL HTML tag names to strip (render children only, remove the tag wrapper). Default: \["noscript"\].
preserve_tags const char** NULL HTML tag names to preserve as raw HTML in output.
exclude_selectors const char** NULL CSS selectors for elements to exclude entirely (element + all content). Unlike strip_tags (which removes the wrapper but keeps children), excluded elements and all descendants are dropped. Supports CSS selectors: .class, #id, \[attribute\], compound selectors. Example: \[".cookie-banner", "#ad-container", "\[role='complementary'\]"\]
skip_images bool false Skip image elements in output. Default: false.
max_depth uintptr_t* NULL Max DOM traversal depth. Prevents stack overflow on deeply nested HTML.
wrap bool false Enable line wrapping. Default: false.
wrap_width uintptr_t 80 Wrap width when wrap is enabled. Default: 80.
include_document_structure bool true Include document structure tree in output. Default: true.

Signature:

CbergContentConfig cberg_default();

Example:

CbergContentConfig *result = cberg_default();

Returns: CbergContentConfig


Information about an HTTP cookie received from a response.

Field Type Default Description
name const char* The cookie name.
value const char* The cookie value.
domain const char** NULL The cookie domain, if specified.
path const char** NULL The cookie path, if specified.

Configuration for crawl, scrape, and map operations.

Field Type Default Description
max_depth uintptr_t* NULL Maximum crawl depth (number of link hops from the start URL).
max_pages uintptr_t* NULL Maximum number of pages to crawl.
max_links_per_page uintptr_t* NULL Maximum links enqueued from a single page. Defaults to 10000. Bounds the work one hostile or pathological page can create; links past the cap are dropped and a warning is logged.
max_concurrent uintptr_t* NULL Maximum number of concurrent requests.
respect_robots_txt bool false Whether to respect robots.txt directives.
soft_http_errors bool false When true, HTTP-level error responses (404 NotFound, 403 Forbidden, WAF blocks) are surfaced as ScrapeResult records with the matching status_code rather than raised as CrawlError. Default false preserves the historical throw-on-error contract for direct fetches. Independently of this flag, 404s reached at the end of a redirect chain are always surfaced softly — the user opted into redirect-following, so receiving a 404 there is part of the normal flow rather than an unexpected error.
user_agent const char** NULL Custom user-agent string.
stay_on_domain bool false Whether to restrict crawling to the same domain.
allow_subdomains bool false Whether to allow subdomains when stay_on_domain is true.
include_paths const char** NULL Regex patterns for paths to include during crawling.
exclude_paths const char** NULL Regex patterns for paths to exclude during crawling.
custom_headers void* NULL Custom HTTP headers to send with each request.
request_timeout uint64_t 30000ms Timeout for individual HTTP requests (in milliseconds when serialized).
rate_limit_ms uint64_t* NULL Per-domain rate limit in milliseconds. When set, enforces a minimum delay between requests to the same domain. Defaults to 200ms when NULL.
max_redirects uintptr_t 10 Maximum number of redirects to follow.
retry_count uintptr_t 0 Number of retry attempts for failed requests.
retry_codes uint16_t* NULL HTTP status codes that should trigger a retry.
cookies_enabled bool false Whether to enable cookie handling.
auth CbergAuthConfig* NULL Authentication configuration.
max_body_size uintptr_t* NULL Maximum response body size in bytes.
remove_tags const char** NULL CSS selectors for tags to remove from HTML before processing.
content CbergContentConfig Content extraction and conversion configuration.
map_limit uintptr_t* NULL Maximum number of URLs to return from a map operation.
map_search const char** NULL Search filter for map results (case-insensitive substring match on URLs).
download_assets bool false Whether to download assets (CSS, JS, images, etc.) from the page.
asset_types CbergAssetCategory* NULL Filter for asset categories to download.
max_asset_size uintptr_t* NULL Maximum size in bytes for individual asset downloads.
browser CbergBrowserConfig Browser configuration.
proxy CbergProxyConfig* NULL Proxy configuration for HTTP requests.
user_agents const char** NULL List of user-agent strings for rotation. If non-empty, overrides user_agent.
capture_screenshot bool false Whether to capture a screenshot when using the browser. Only supported by scrape() with BrowserBackend.Chromiumoxide and BrowserMode.Always or Stealth. A screenshot is 100–500 KB of PNG per page, so crawl() does not carry screenshots in CrawlPageResult/CrawlResult at all — a multi-thousand-page crawl holding one per page in memory is not a safe default. Setting this with any other configuration (a different backend, BrowserMode.Auto/Never, or during crawl()) has no effect and logs a warning rather than silently doing nothing.
follow_document_urls bool false Re-enqueue discovered LinkType.Document URLs into the crawl frontier so the crawl follows links from document pages (PDFs, etc.) as it would from HTML pages. Default: false (documents terminate at materialisation).
document_url_depth uint32_t* NULL Maximum document-depth (from the seed URL through document links only) when follow_document_urls is true. NULL means inherit max_depth. Independent of max_depth: a document URL is enqueued only if BOTH the outer max_depth and (if set) document_url_depth permit it.
download_documents bool true Whether to download non-HTML documents (PDF, DOCX, images, code, etc.) instead of skipping them. Defaults to true — unlike download_assets and capture_screenshot, which default to false.
document_max_size uintptr_t* 52428800 Maximum size in bytes for document downloads. Defaults to 50 MB.
document_mime_types const char** NULL Allowlist of MIME types to download. If empty, uses built-in defaults.
document_output_dir const char** NULL Directory to stream downloaded document bytes into instead of holding them in memory on DownloadedDocument.content. When set, content is left empty and DownloadedDocument.content_path is populated with <dir>/<content_hash>.<ext>. NULL (default) preserves today’s in-memory-only behavior. Has no effect on wasm32, which has no filesystem — use document_content_encoding there instead.
document_content_encoding CbergDocumentContentEncoding* NULL Opt-in encoding that duplicates DownloadedDocument.content into a serializable field for language bindings that need the bytes in-memory (content itself is alef(skip)ed). NULL (default) means no encoding is produced. Independent of document_output_dir — set both to get a file on disk and an in-memory copy.
warc_output const char** NULL Path to write WARC output. If NULL, WARC output is disabled.
browser_profile const char** NULL Named browser profile for persistent sessions (cookies, localStorage). Chromiumoxide backend only. The native backend runs an in-process JavaScript engine with no Chrome process and therefore no profile directory, so this is ignored there and logs a warning. It is also ignored — with a warning — when a shared browser pool is in use (the pool launches before any per-crawl config exists) or when connecting to an external CDP endpoint whose process crawlberg does not own.
save_browser_profile bool false Whether to save changes back to the browser profile on exit.
ssrf CbergSsrfPolicy SSRF policy for outbound network requests. Default: deny private networks, allow http/https only, max 5 redirects. deny_private, allowlist and max_redirects are exposed to all language bindings. scheme_allowlist stays Rust-only — see SsrfPolicy. wasm32 (including Node.js): deny_private does not stop hostname-based requests. There is no DNS resolution on this target, so only a literal IP host is checked against the policy — a domain name is always permitted, regardless of deny_private. Under Node, where fetch enforces no CORS, this means a service embedding the wasm binding can be driven to internal hosts by domain name even with deny_private = true. Enforce egress restrictions at the network layer for that deployment target; do not rely on this field. See crawlberg.net.validate_url.
ssrf_deny_private_explicit bool* NULL Pins SsrfPolicy.deny_private to a caller-chosen value, bypassing the CRAWLBERG_ALLOW_PRIVATE_NETWORK operator override entirely for this config. ssrf.deny_private is a plain, always-serialized bool: several alef-generated bindings construct SsrfPolicy.default() (hardcoding deny_private: true) whenever their caller never touches SSRF settings at all, so true on that field alone cannot distinguish “the caller wants private networks denied” from “the binding’s own structural default landed on true”. The environment variable exists precisely to resolve that ambiguity in the common case by treating any true as inconclusive and deferring to the operator. Set this field when that default-deferral is wrong for your call — e.g. a test that must prove deny_private: true still denies even while the operator has set CRAWLBERG_ALLOW_PRIVATE_NETWORK suite-wide for every other call. NULL (default) preserves today’s behavior: the environment variable may still flip ssrf.deny_private to false. Some(value) pins ssrf.deny_private to value and the environment variable is not consulted for this config.

Signature:

CbergCrawlConfig cberg_default();

Example:

CbergCrawlConfig *result = cberg_default();

Returns: CbergCrawlConfig

Validate the configuration, returning an error if any values are invalid.

Signature:

void cberg_validate();

Example:

cberg_validate(instance);

Returns: No return value.

Errors: Returns NULL on error.


Opaque handle to a configured crawl engine.

Constructed via create_engine with an optional CrawlConfig. Default implementations for all pluggable components are used internally.


The result of crawling a single page during a crawl operation.

Field Type Default Description
url const char* The original URL of the page.
normalized_url const char* The normalized URL of the page.
status_code uint16_t The HTTP status code of the response.
content_type const char* The Content-Type header value.
html const char* The HTML body of the response.
body_size uintptr_t The size of the response body in bytes.
metadata CbergPageMetadata Extracted metadata from the page.
links CbergLinkInfo* NULL Links found on the page.
images CbergImageInfo* NULL Images found on the page.
feeds CbergFeedInfo* NULL Feed links found on the page.
json_ld CbergJsonLdEntry* NULL JSON-LD entries found on the page.
depth uintptr_t The depth of this page from the start URL.
stayed_on_domain bool Whether this page is on the same domain as the start URL.
was_skipped bool Whether this page was skipped (binary or PDF content).
is_pdf bool Whether the content is a PDF.
detected_charset const char** NULL The detected character set encoding.
markdown CbergMarkdownResult* NULL Markdown conversion of the page content.
extracted_data void** NULL Structured data extracted by LLM. Populated when extraction is configured.
extraction_meta CbergExtractionMeta* NULL Metadata about the LLM extraction pass (cost, tokens, model).
downloaded_document CbergDownloadedDocument* NULL Downloaded non-HTML document (PDF, DOCX, image, code, etc.).
browser_used bool Whether the browser fallback was used to fetch this page.

The result of a multi-page crawl operation.

Field Type Default Description
pages CbergCrawlPageResult* NULL The list of crawled pages.
final_url const char* The final URL after following redirects.
redirect_count uintptr_t The number of redirects followed.
was_skipped bool Whether any page was skipped during crawling.
error const char** NULL An error message, if the crawl encountered an issue.
cookies CbergCookieInfo* NULL Cookies collected during the crawl.
stayed_on_domain bool Whether all crawled pages stayed on the same domain as the start URL.
browser_used bool Whether the browser fallback was used for any page in this crawl.

Returns the count of unique normalized URLs encountered during crawling.

Computed from pages (not the deprecated normalized_urls field) so it is correct across every binding that reconstructs CrawlResult from pages alone. In streaming mode pages is empty, so this returns 0 on the opaque-handle (C/Go/C#/Zig/Dart) path where it previously counted streamed pages — a known, accepted cost of making the other ten binding families correct.

Signature:

uintptr_t cberg_unique_normalized_urls();

Example:

uintptr_t result = cberg_unique_normalized_urls(instance);

Returns: uintptr_t


Request to begin a single-URL streaming crawl.

Wraps a single seed URL for delivery through the streaming-adapter binding surface. Required as a struct because alef’s streaming adapter requires a named request type — primitives are not supported.

Field Type Default Description
url const char* The seed URL to crawl.

A downloaded asset from a page.

Field Type Default Description
url const char* The original URL of the asset.
content_hash const char* The SHA-256 content hash of the asset.
mime_type const char** NULL The MIME type from the Content-Type header.
size uintptr_t The size of the asset in bytes.
asset_category CbergAssetCategory CBERG_CBERG_IMAGE The category of the asset.
html_tag const char** NULL The HTML tag that referenced this asset (e.g., “link”, “script”, “img”).

A downloaded non-HTML document (PDF, DOCX, image, code file, etc.).

When the crawler encounters non-HTML content and download_documents is enabled, it downloads the raw bytes and populates this struct instead of skipping the resource.

Field Type Default Description
url const char* The URL the document was fetched from.
mime_type const char* The MIME type from the Content-Type header.
size uintptr_t Size of the document in bytes.
filename const char** NULL Filename extracted from Content-Disposition or URL path.
content_hash const char* SHA-256 hex digest of the content.
headers void* NULL Selected response headers.
truncated bool True when content (or the file at content_path) was truncated to document_max_size; size still reports the original, untruncated length.
content_path const char** NULL Filesystem path the document was streamed to when document_output_dir was set. content is empty in memory when this is populated.
content_base64 const char** NULL Base64-encoded copy of content, populated only when document_content_encoding was set to Base64.

Metadata about an LLM extraction pass.

Field Type Default Description
cost double* NULL Estimated cost of the LLM call in USD.
prompt_tokens uint64_t* NULL Number of prompt (input) tokens consumed.
completion_tokens uint64_t* NULL Number of completion (output) tokens generated.
model const char** NULL The model identifier used for extraction.
chunks_processed uintptr_t Number of content chunks sent to the LLM.

Information about a favicon or icon link.

Field Type Default Description
url const char* The icon URL.
rel const char* The rel attribute (e.g., “icon”, “apple-touch-icon”).
sizes const char** NULL The sizes attribute, if present.
mime_type const char** NULL The MIME type, if present.

Information about a feed link found on a page.

Field Type Default Description
url const char* The feed URL.
title const char** NULL The feed title, if present.
feed_type CbergFeedType CBERG_CBERG_RSS The type of feed.

A heading element extracted from the page.

Field Type Default Description
level uint8_t The heading level (1-6).
text const char* The heading text content.

An hreflang alternate link entry.

Field Type Default Description
lang const char* The language code (e.g., “en”, “fr”, “x-default”).
url const char* The URL for this language variant.

Information about an image found on a page.

Field Type Default Description
url const char* The image URL.
alt const char** NULL The alt text, if present.
width uint32_t* NULL The width attribute, if present and parseable.
height uint32_t* NULL The height attribute, if present and parseable.
source CbergImageSource CBERG_CBERG_IMG The source of the image reference.

Result of executing a sequence of page interaction actions.

Field Type Default Description
action_results CbergActionResult* NULL Results from each executed action.
final_html const char* Final page HTML after all actions completed.
final_url const char* Final page URL (may have changed due to navigation).
screenshot_base64 const char** NULL Base64-encoded PNG screenshot taken after all actions. Populated only when a PageAction.Screenshot action actually ran, so callers that never request a screenshot do not pay the encoding cost.

A JSON-LD structured data entry found on a page.

Field Type Default Description
schema_type const char* The @type value from the JSON-LD object.
name const char** NULL The name value, if present.
raw const char* The raw JSON-LD string.

Information about a link found on a page.

Field Type Default Description
url const char* The resolved URL of the link.
text const char* The visible text of the link.
link_type CbergLinkType CBERG_CBERG_INTERNAL The classification of the link.
rel const char** NULL The rel attribute value, if present.
nofollow bool Whether the link has rel="nofollow".

The result of a map operation, containing discovered URLs.

Field Type Default Description
urls CbergSitemapUrl* NULL The list of discovered URLs.

Rich markdown conversion result from HTML processing.

Field Type Default Description
content const char* Converted markdown text.
document_structure void** NULL Structured document tree with semantic nodes.
tables void** NULL Extracted tables with structured cell data.
warnings const char** NULL Non-fatal processing warnings.
citations bool Whether citation conversion was applied and produced at least one reference. true when the markdown contained inline links that were converted to numbered citation references. The converted content (with \[N\] markers) is available in content; the full reference list is accessible via generate_citations if needed separately.
fit_content const char** NULL Content-filtered markdown optimized for LLM consumption.

Metadata extracted from an HTML page’s <meta> tags and <title> element.

Field Type Default Description
title const char** NULL The page title from the <title> element.
description const char** NULL The meta description.
canonical_url const char** NULL The canonical URL from <link rel="canonical">.
keywords const char** NULL Keywords from <meta name="keywords">.
author const char** NULL Author from <meta name="author">.
viewport const char** NULL Viewport content from <meta name="viewport">.
theme_color const char** NULL Theme color from <meta name="theme-color">.
generator const char** NULL Generator from <meta name="generator">.
robots const char** NULL Robots content from <meta name="robots">.
html_lang const char** NULL The lang attribute from the <html> element.
html_dir const char** NULL The dir attribute from the <html> element.
og_title const char** NULL Open Graph title.
og_type const char** NULL Open Graph type.
og_image const char** NULL Open Graph image URL.
og_description const char** NULL Open Graph description.
og_url const char** NULL Open Graph URL.
og_site_name const char** NULL Open Graph site name.
og_locale const char** NULL Open Graph locale.
og_video const char** NULL Open Graph video URL.
og_audio const char** NULL Open Graph audio URL.
og_locale_alternates const char*** NULL Open Graph locale alternates.
twitter_card const char** NULL Twitter card type.
twitter_title const char** NULL Twitter title.
twitter_description const char** NULL Twitter description.
twitter_image const char** NULL Twitter image URL.
twitter_site const char** NULL Twitter site handle.
twitter_creator const char** NULL Twitter creator handle.
dc_title const char** NULL Dublin Core title.
dc_creator const char** NULL Dublin Core creator.
dc_subject const char** NULL Dublin Core subject.
dc_description const char** NULL Dublin Core description.
dc_publisher const char** NULL Dublin Core publisher.
dc_date const char** NULL Dublin Core date.
dc_type const char** NULL Dublin Core type.
dc_format const char** NULL Dublin Core format.
dc_identifier const char** NULL Dublin Core identifier.
dc_language const char** NULL Dublin Core language.
dc_rights const char** NULL Dublin Core rights.
article CbergArticleMetadata* NULL Article metadata from article:* Open Graph tags.
hreflangs CbergHreflangEntry** NULL Hreflang alternate links.
favicons CbergFaviconInfo** NULL Favicon and icon links.
headings CbergHeadingInfo** NULL Heading elements (h1-h6).
word_count uintptr_t* NULL Computed word count of the page body text.

Proxy configuration for HTTP requests.

Field Type Default Description
url const char* Proxy URL (e.g. “http://proxy:8080", “socks5://proxy:1080”).
username const char** NULL Optional username for proxy authentication.
password const char** NULL Optional password for proxy authentication.

Response metadata extracted from HTTP headers.

Field Type Default Description
etag const char** NULL The ETag header value.
last_modified const char** NULL The Last-Modified header value.
cache_control const char** NULL The Cache-Control header value.
server const char** NULL The Server header value.
x_powered_by const char** NULL The X-Powered-By header value.
content_language const char** NULL The Content-Language header value.
content_encoding const char** NULL The Content-Encoding header value.

The result of a single-page scrape operation.

Field Type Default Description
status_code uint16_t The HTTP status code of the response.
final_url const char* The final URL after following all redirects.
content_type const char* The Content-Type header value.
html const char* The HTML body of the response.
body_size uintptr_t The size of the response body in bytes.
metadata CbergPageMetadata Extracted metadata from the page.
links CbergLinkInfo* NULL Links found on the page.
images CbergImageInfo* NULL Images found on the page.
feeds CbergFeedInfo* NULL Feed links found on the page.
json_ld CbergJsonLdEntry* NULL JSON-LD entries found on the page.
is_allowed bool Whether the URL is allowed by robots.txt.
crawl_delay uint64_t* NULL The crawl delay from robots.txt, in seconds.
noindex_detected bool Whether a noindex directive was detected.
nofollow_detected bool Whether a nofollow directive was detected.
x_robots_tag const char** NULL The X-Robots-Tag header value, if present.
is_pdf bool Whether the content is a PDF.
was_skipped bool Whether the page was skipped (binary or PDF content).
detected_charset const char** NULL The detected character set encoding.
auth_header_sent bool Whether an authentication header was sent with the request.
response_meta CbergResponseMeta* NULL Response metadata extracted from HTTP headers.
assets CbergDownloadedAsset* NULL Downloaded assets from the page.
js_render_hint bool Whether the page content suggests JavaScript rendering is needed.
browser_used bool Whether the browser fallback was used to fetch this page.
markdown CbergMarkdownResult* NULL Markdown conversion of the page content.
extracted_data void** NULL Structured data extracted by LLM. Populated when extraction is configured.
extraction_meta CbergExtractionMeta* NULL Metadata about the LLM extraction pass (cost, tokens, model).
screenshot_base64 const char** NULL Base64-encoded PNG screenshot of the page. Populated only when CrawlConfig.capture_screenshot was enabled for this request, so callers that never requested a screenshot do not pay the encoding cost.
downloaded_document CbergDownloadedDocument* NULL Downloaded non-HTML document (PDF, DOCX, image, code, etc.).
browser CbergBrowserExtras* NULL Browser-specific extras (eval result, network events, cookies). Only populated when BrowserBackend.Native was used for this request.

A URL entry from a sitemap.

Field Type Default Description
url const char* The URL.
lastmod const char** NULL The last modification date, if present.
changefreq const char** NULL The change frequency, if present.
priority const char** NULL The priority, if present.

SSRF policy configuration.

Field Type Default Description
deny_private bool true If true, reject URLs that resolve to private/metadata IP ranges.
allowlist CbergHostMatcher* NULL Hostnames and IP ranges permitted regardless of deny_private. The allowlist is an override of deny_private, not an intersection with it. Precedence, in order: 1. deny_private == false permits everything; the allowlist is not consulted. 2. A hostname matching an Exact or Suffix entry is permitted immediately, before DNS resolution — so the deny-list is never applied to it. This trusts the host string: a name that resolves into private space is still permitted. 3. A literal or resolved IP inside a Cidr entry is permitted even though it is in the default deny-list. 4. Otherwise the default deny-list decides. An empty allowlist therefore denies nothing by itself — it simply leaves deny_private and the deny-list in sole control.
max_redirects uint8_t 5 Maximum number of HTTP redirects to follow during validation.

Signature:

CbergSsrfPolicy cberg_default();

Example:

CbergSsrfPolicy *result = cberg_default();

Returns: CbergSsrfPolicy

Create a policy from environment variables.

On native platforms, reads CRAWLBERG_ALLOW_PRIVATE_NETWORK — if set to “1” or “true” (case-insensitive), sets deny_private = false. Otherwise, defaults to deny_private = true.

On wasm32 targets (browser/Node.js), environment variables are not accessible to the compiled module. Defaults to deny_private = false because:

  • Outbound requests in a browser go through the fetch API, which enforces its own network policies.
  • Rust-side SSRF checking is unenforceable and redundant in a wasm32 context.
  • For testing and localhost access, the host’s network sandbox is the enforcing boundary.

Node.js caveat: deny_private (whatever its value) has no effect on hostname-based requests under wasm32. There is no DNS resolution on this target, so validate_url only ever checks a literal IP host; a domain name falls straight through to Ok(()). In a browser this is covered by same-origin/CORS. Node’s fetch enforces no CORS, so a Node service embedding this wasm module can be driven to internal hosts by domain name even though deny_private = true. Do not rely on this policy to stop that in Node — enforce egress restrictions (network policy, firewall, proxy allowlist) outside the process.

Signature:

CbergSsrfPolicy cberg_from_env();

Example:

CbergSsrfPolicy *result = cberg_from_env();

Returns: CbergSsrfPolicy


When to use the headless browser fallback.

Value Description
CBERG_AUTO Automatically detect when JS rendering is needed and fall back to browser.
CBERG_ALWAYS Always use the browser for every request.
CBERG_NEVER Never use the browser fallback.
CBERG_STEALTH Always use the browser with all stealth surfaces enabled. Behaves like Always for escalation purposes (every request is routed through the browser tier), but additionally enables: - browser JavaScript stealth patches - native-backend TLS fingerprint spoofing - stealth-aware default user-agent when no explicit UA is set - 1920×1080 viewport override Use this instead of setting the now-removed BrowserConfig.stealth boolean field.

Wait strategy for browser page rendering.

Value Description
CBERG_NETWORK_IDLE Wait until network activity is idle.
CBERG_SELECTOR Wait for a specific CSS selector to appear in the DOM.
CBERG_FIXED Wait for a fixed duration after navigation.

Browser backend used for JavaScript rendering.

Value Description
CBERG_CHROMIUMOXIDE Existing Chromium/CDP backend powered by chromiumoxide.
CBERG_NATIVE Crawlberg-owned native browser backend derived from Obscura.

Opt-in encoding applied to a downloaded document’s bytes for callers who need the content available in a serializable field rather than reading it from disk.

NULL (the CrawlConfig.document_content_encoding default) produces neither — unlike screenshots, base64-encoding a document by default would duplicate an already up-to-document_max_size buffer (50 MB default) in memory per document.

Value Description
CBERG_BASE64 Populate DownloadedDocument.content_base64 with a base64-encoded copy.

Authentication configuration.

Value Description
CBERG_BASIC HTTP Basic authentication. — Fields: username: const char*, password: const char*
CBERG_BEARER Bearer token authentication. — Fields: token: const char*
CBERG_HEADER Custom authentication header. — Fields: name: const char*, value: const char*

The classification of a link.

Value Description
CBERG_INTERNAL A link to the same domain.
CBERG_EXTERNAL A link to a different domain.
CBERG_ANCHOR A fragment-only link (e.g., #section).
CBERG_DOCUMENT A link to a downloadable document (PDF, DOC, etc.).

The source of an image reference.

Value Description
CBERG_IMG An <img> tag.
CBERG_PICTURE_SOURCE A <source> tag inside <picture>.
CBERG_OG_IMAGE An og:image meta tag.
CBERG_TWITTER_IMAGE A twitter:image meta tag.

The type of a feed (RSS, Atom, or JSON Feed).

Value Description
CBERG_RSS RSS feed.
CBERG_ATOM Atom feed.
CBERG_JSON_FEED JSON Feed.

The category of a downloaded asset.

Value Description
CBERG_DOCUMENT A document file (PDF, DOC, etc.).
CBERG_IMAGE An image file.
CBERG_AUDIO An audio file.
CBERG_VIDEO A video file.
CBERG_FONT A font file.
CBERG_STYLESHEET A CSS stylesheet.
CBERG_SCRIPT A JavaScript file.
CBERG_ARCHIVE An archive file (ZIP, TAR, etc.).
CBERG_DATA A data file (JSON, XML, CSV, etc.).
CBERG_OTHER An unrecognized asset type.

An event emitted during a streaming crawl operation.

Not available on wasm32 targets — streaming requires native concurrency primitives (tokio channels, JoinSet) that are not supported on wasm32.

Delivered to bindings through each target’s native streaming idiom.

Value Description
CBERG_PAGE A single page has been crawled. — Fields: result: CbergCrawlPageResult
CBERG_ERROR An error occurred while crawling a URL. — Fields: url: const char*, error: const char*
CBERG_COMPLETE The crawl has completed. — Fields: pages_crawled: uintptr_t

A single page interaction action.

Actions are serialized with a type tag using camelCase naming, except ExecuteJs which is explicitly renamed to "executeJs".

Value Description
CBERG_CLICK Click on an element matching the given CSS selector. — Fields: selector: const char*
CBERG_TYPE_TEXT Type text into an element matching the given CSS selector. — Fields: selector: const char*, text: const char*
CBERG_PRESS Press a keyboard key (e.g. “Enter”, “Tab”, “Escape”). — Fields: key: const char*
CBERG_SCROLL Scroll the page or a specific element. — Fields: direction: CbergScrollDirection, selector: const char*, amount: int64_t
CBERG_WAIT Wait for a duration or for an element to appear. — Fields: milliseconds: int64_t, selector: const char*
CBERG_SCREENSHOT Take a screenshot of the current page. — Fields: full_page: bool
CBERG_EXECUTE_JS Execute arbitrary JavaScript in the page context. Safety: The script runs with full page privileges in the browser context. Only execute scripts from trusted sources. — Fields: script: const char*
CBERG_SCRAPE Scrape the current page HTML.

Direction for a scroll action.

Value Description
CBERG_UP Scroll upward.
CBERG_DOWN Scroll downward.

Hostname/IP allowlist matcher for SSRF policy.

Serializes as an internally-tagged object so each variant is distinguishable on the wire and round-trips losslessly:

{"type": "exact", "value": "api.example.com"}
{"type": "suffix", "value": ".example.com"}
{"type": "cidr", "value": "10.0.0.0/8"}

A bare JSON string is still accepted on deserialization and resolves to Exact, preserving configs written against the previous untagged representation.

Exact: HostMatcher.Exact

Value Description
CBERG_EXACT Exact hostname match (case-insensitive). — Fields: value: const char*
CBERG_SUFFIX Suffix match: “.xberg.io” matches “api.xberg.io” and “xberg.io”. — Fields: value: const char*
CBERG_CIDR CIDR match: “10.0.0.0/8” matches IP addresses in that range. — Fields: value: const char*

Errors that can occur during crawling, scraping, or mapping operations.

Variant Description
CBERG_NOT_FOUND The requested page was not found (HTTP 404).
CBERG_UNAUTHORIZED The request was unauthorized (HTTP 401).
CBERG_FORBIDDEN The request was forbidden (HTTP 403).
CBERG_WAF_BLOCKED The request was blocked by a WAF or bot protection (HTTP 403 with WAF indicators). vendor is the lowercase identifier of the detected WAF (e.g. “cloudflare”, “datadome”). When the engine cannot identify the vendor, it uses “unknown”. message is the freeform description for logs and human readers. The stable error tag remains forbidden: waf/blocked: MESSAGE so existing log-grep patterns and cross-language bindings continue to work; vendor is surfaced separately for structured consumers.
CBERG_TIMEOUT The request timed out.
CBERG_RATE_LIMITED The request was rate-limited (HTTP 429).
CBERG_SERVER_ERROR A server error occurred (HTTP 5xx).
CBERG_BAD_GATEWAY A bad gateway error occurred (HTTP 502).
CBERG_GONE The resource is permanently gone (HTTP 410).
CBERG_CONNECTION A connection error occurred.
CBERG_DNS A DNS resolution error occurred.
CBERG_SSL An SSL/TLS error occurred.
CBERG_DATA_LOSS Data was lost or truncated during transfer.
CBERG_BROWSER_ERROR The browser failed to launch, connect, or navigate.
CBERG_BROWSER_TIMEOUT The browser page load or rendering timed out.
CBERG_INVALID_CONFIG The provided configuration is invalid.
CBERG_UNSUPPORTED The requested capability is not supported by the active backend or build.
CBERG_SSRF_POLICY_VIOLATION A URL was rejected by SSRF policy (private IP, metadata, disallowed scheme, etc).
CBERG_OTHER An unclassified error occurred.

SSRF validation error.

Variant Description
CBERG_DENIED_BY_POLICY URL denied by SSRF policy: private IP, metadata IP, etc.
CBERG_NOT_ON_ALLOWLIST Host not on allowlist when an allowlist is configured.
CBERG_INVALID_CIDR Allowlist entry is not a parseable CIDR block.
CBERG_DNS_RESOLUTION_FAILED DNS resolution failed for hostname.
CBERG_INVALID_URL Invalid URL format.
CBERG_DISALLOWED_SCHEME URL scheme not in allowlist (e.g., ftp:// when only http/https allowed).
CBERG_TOO_MANY_REDIRECTS Too many HTTP redirects encountered during validation.