# SRU Catalog Harvester (`datamule/sru-catalog-harvester`) Actor Point at ANY SRU/SRW library catalog (DNB, Library of Congress, K10plus and thousands more — one LoC standard) and get flat bibliographic rows from a CQL query: title, creator, publisher, date, subject, ISBN and more, plus lossless raw XML. Discovery mode lists a server's indexes. Pay per record. - **URL**: https://apify.com/datamule/sru-catalog-harvester.md - **Developed by:** [Datamule](https://apify.com/datamule) (community) - **Categories:** Developer tools - **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks - **User rating**: No ratings yet ## Pricing from $0.35 / 1,000 records This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events. Since this Actor supports Apify Store discounts, the price gets lower the higher subscription plan you have. Learn more: https://docs.apify.com/platform/actors/running/actors-in-store#pay-per-event ## What's an Apify Actor? Actors are a software tools running on the Apify platform, for all kinds of web data extraction and automation use cases. In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours, and optionally produces a well-defined JSON output, datasets with results, or files in key-value store. In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server. Actors are written with capital "A". ## How to integrate an Actor? If asked about integration, you help developers integrate Actors into their projects. You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready. The best way to integrate Actors is as follows. In JavaScript/TypeScript projects, use official [JavaScript/TypeScript client](https://docs.apify.com/api/client/js.md): ```bash npm install apify-client ``` In Python projects, use official [Python client library](https://docs.apify.com/api/client/python.md): ```bash pip install apify-client ``` In shell scripts, use [Apify CLI](https://docs.apify.com/cli/docs.md): ````bash # MacOS / Linux curl -fsSL https://apify.com/install-cli.sh | bash # Windows irm https://apify.com/install-cli.ps1 | iex ```bash In AI frameworks, you might use the [Apify MCP server](https://docs.apify.com/platform/integrations/mcp.md). If your project is in a different language, use the [REST API](https://docs.apify.com/api/v2.md). For usage examples, see the [API](#api) section below. For more details, see Apify documentation as [Markdown index](https://docs.apify.com/llms.txt) and [Markdown full-text](https://docs.apify.com/llms-full.txt). # README ## SRU Catalog Harvester **Point at ANY SRU/SRW library catalog server and get flat, structured bibliographic rows — one actor for thousands of library catalogs.** **SRU** (*Search/Retrieve via URL*) is the Library of Congress' standard protocol for querying bibliographic catalogs over plain HTTP, together with its sibling **SRW**. It is spoken by a huge population of national, university and union library catalogs — the German National Library (DNB), the **Library of Congress**, the Bibliothèque nationale de France (BnF), the Koninklijke Bibliotheek (KB-NL), the National Library of Australia's **Trove**, the **K10plus / GBV** union catalog, and hundreds more. Every one of them answers the identical `operation=searchRetrieve` grammar and returns the same `` envelope. Every other "library" or "catalog" scraper wraps **one** endpoint. This actor is the **generic runner**: give it any SRU server's base URL and a CQL query, and it turns the matching records into dataset rows — cleanly flattened columns plus a lossless copy of each original record. ### What it does - **`searchRetrieve` (default):** runs your CQL `query` against `base_url`, reads the server's total (`numberOfRecords`), and paginates via `startRecord` until the result set is exhausted or your global `maxRecords` cap is reached. Each record becomes one flat row. - **`explain` (discovery):** fetches the server's self-description and emits one row per **searchable index** (name, set, title, searchable/sortable flags) plus a server-info row (title, host, database, available record schemas). A cheap way to learn what a server supports before querying it. Robust to the ways SRU servers differ in practice: - **Namespaces & prefixes vary** — DNB serves the envelope on the default namespace, the Library of Congress prefixes it `zs:`, K10plus uses the OASIS SRU-2.0 namespace. Every element is matched by its **local name**, so this is handled transparently. - **Record schemas vary** — **Dublin Core** (`oai_dc` / `dc`) is flattened to clean columns; **MARCXML** is decoded from the standard MARC tags (245 title, 1xx/700 authors, 26x imprint, 020 ISBN, 6xx subjects); any other schema (MODS, ESE, …) still yields a structured `fields` map. A lossless **`raw`** string always preserves the complete original record XML. - **SRU 1.1 / 1.2 / 2.0** are all supported. A query that matches nothing returns 0 records and exits cleanly; a server-side diagnostic (e.g. an unsupported index) is surfaced as a warning, never a crash. ### Input | Field | Type | Description | |-------|------|-------------| | `base_url` *(required)* | string | The SRU/SRW endpoint, e.g. `https://services.dnb.de/sru/dnb` (DNB), `http://lx2.loc.gov:210/lcdb` (Library of Congress), `https://sru.k10plus.de/gvk` (K10plus). | | `query` | string | A **CQL** search expression, e.g. `dc.title=climate`, `dc.creator=goethe`, or a bare keyword. Required for `searchRetrieve`. Run `explain` first to discover a server's indexes. | | `operation` | string | `searchRetrieve` (default) or `explain` (describe the server). | | `recordSchema` | string | Metadata schema to request: `oai_dc` / `dc`, `marcxml` / `MARC21-xml`, `mods`, … Leave empty for the server default. | | `maximumRecords` | integer | Records per SRU page (most servers cap at 100). Default 50. | | `maxRecords` | integer | **Global** cap on total records harvested across all pages. Leave empty to fetch a single page (cost-safe). | | `startRecord` | integer | 1-based position of the first record (SRU is 1-indexed). Default 1. | | `sruVersion` | string | `1.1` (default), `1.2` or `2.0`. | | `bearer` | string (secret) | Optional bearer token for gated deployments. Never logged. | | `extraHeaders` | object | Optional extra HTTP headers, e.g. `{"x-api-key": "…"}`. Never logged. | ### Output One dataset item per record. A Dublin Core result from the DNB, for example: ```json { "_recordSchema": "oai_dc", "_recordPosition": 1, "_base_url": "https://services.dnb.de/sru/dnb", "_query": "dc.title=climate", "_numberOfRecords": 48992, "title": "SDG 13: Climate Action", "creator": "Leal Filho, Walter [Herausgeber]", "creators": ["Leal Filho, Walter [Herausgeber]", "Scherenberg, Viviane [Herausgeber]"], "publisher": "Springer Spektrum", "date": "2027", "subject": ["550 Geowissenschaften"], "identifier": "978-3-662-72215-2", "identifiers": ["978-3-662-72215-2", "3-662-72215-1", "1373318015"], "language": "eng", "raw": "…" } ```` Missing fields are `null`; `raw` always preserves the complete original record XML so nothing is lost. ### Finding servers Registries of SRU/SRW endpoints include the Library of Congress' [SRU implementors list](https://www.loc.gov/standards/sru/resources/implementors.html) and each national library's developer pages. Any endpoint that answers `operation=explain` works with this actor. ### Pricing Pay-per-event: **$0.0005 per record** (one emitted dataset row). Leave `maxRecords` empty for a single cost-safe page, or set it to harvest a larger result set. ### Notes & limits - Scope is the SRU/SRW **search** protocol returning XML records (Dublin Core, MARCXML, and other XML schemas via the generic `fields` + `raw` view). - Binary formats (e.g. MARC-in-ISO2709 delivered as a base64 blob) are preserved in `raw` but not decoded. - A malformed `base_url`, a non-XML response, or an HTTP 4xx returns a clear error; an empty result set simply yields 0 records. # Actor input Schema ## `base_url` (type: `string`): The base URL of any SRU (Search/Retrieve via URL) or SRW server — the Library of Congress standard protocol spoken by most national, university and union library catalogs. Examples: https://services.dnb.de/sru/dnb (German National Library), http://lx2.loc.gov:210/lcdb (Library of Congress), https://sru.k10plus.de/gvk (K10plus/GBV union catalog). One actor works against thousands of these. ## `query` (type: `string`): A CQL (Contextual Query Language) search expression, e.g. dc.title=climate, dc.creator=goethe, or a bare keyword. The exact indexes a server supports vary — run this actor once with operation=explain to list them. Required for a searchRetrieve; ignored for explain. ## `operation` (type: `string`): searchRetrieve (default) runs the query and returns bibliographic records. explain fetches the server's self-description and lists its searchable indexes and available record schemas — a cheap way to discover a server before querying it. ## `recordSchema` (type: `string`): The metadata schema to request per record. oai\_dc / dc (Dublin Core) flattens to clean columns; MARC21-xml / marcxml is decoded from standard MARC tags. Any other schema still yields a structured fields map + the lossless raw XML. Leave empty to use the server's default. Common values: oai\_dc, dc, marcxml, MARC21-xml, mods. ## `maximumRecords` (type: `integer`): How many records to request per SRU page (the server's maximumRecords parameter). Most servers cap this at 100. Default 50. ## `maxRecords` (type: `integer`): A GLOBAL cap on the total number of records to harvest across all pages (each emitted record is one billable event). Leave empty to fetch a single page (equal to Records per page) — a cost-safe default. Set higher to auto-paginate through a large result set. ## `startRecord` (type: `integer`): The 1-based position of the first record to return (SRU is 1-indexed). Use to resume or skip into a result set. Default 1. ## `sruVersion` (type: `string`): The SRU protocol version to send. Most servers accept 1.1; some require 1.2 or 2.0. The response is parsed the same way regardless. Default 1.1. ## `bearer` (type: `string`): Optional bearer token for gated SRU deployments (sent as Authorization: Bearer \*\*\*). Not required for public library catalogs. Never logged. ## `extraHeaders` (type: `object`): Optional extra HTTP headers as a JSON object, e.g. {"x-api-key": "..."} for gated servers. Not required for public servers. Header values are never logged. ## Actor input object example ```json { "base_url": "https://services.dnb.de/sru/dnb", "query": "dc.title=climate", "operation": "searchRetrieve", "recordSchema": "oai_dc", "maximumRecords": 50, "startRecord": 1, "sruVersion": "1.1" } ``` # Actor output Schema ## `results` (type: `string`): No description # API You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup. ## JavaScript example ```javascript import { ApifyClient } from 'apify-client'; // Initialize the ApifyClient with your Apify API token // Replace the '' with your token const client = new ApifyClient({ token: '', }); // Prepare Actor input const input = { "base_url": "https://services.dnb.de/sru/dnb", "query": "dc.title=climate", "recordSchema": "oai_dc" }; // Run the Actor and wait for it to finish const run = await client.actor("datamule/sru-catalog-harvester").call(input); // Fetch and print Actor results from the run's dataset (if any) console.log('Results from dataset'); console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`); const { items } = await client.dataset(run.defaultDatasetId).listItems(); items.forEach((item) => { console.dir(item); }); // 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs ``` ## Python example ```python from apify_client import ApifyClient # Initialize the ApifyClient with your Apify API token # Replace '' with your token. client = ApifyClient("") # Prepare the Actor input run_input = { "base_url": "https://services.dnb.de/sru/dnb", "query": "dc.title=climate", "recordSchema": "oai_dc", } # Run the Actor and wait for it to finish run = client.actor("datamule/sru-catalog-harvester").call(run_input=run_input) # Fetch and print Actor results from the run's dataset (if there are any) print("💾 Check your data here: https://console.apify.com/storage/datasets/" + run["defaultDatasetId"]) for item in client.dataset(run["defaultDatasetId"]).iterate_items(): print(item) # 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start ``` ## CLI example ```bash echo '{ "base_url": "https://services.dnb.de/sru/dnb", "query": "dc.title=climate", "recordSchema": "oai_dc" }' | apify call datamule/sru-catalog-harvester --silent --output-dataset ``` ## MCP server setup ```json { "mcpServers": { "apify": { "command": "npx", "args": [ "mcp-remote", "https://mcp.apify.com/?tools=datamule/sru-catalog-harvester", "--header", "Authorization: Bearer " ] } } } ``` ## OpenAPI specification ```json { "openapi": "3.0.1", "info": { "title": "SRU Catalog Harvester", "description": "Point at ANY SRU/SRW library catalog (DNB, Library of Congress, K10plus and thousands more — one LoC standard) and get flat bibliographic rows from a CQL query: title, creator, publisher, date, subject, ISBN and more, plus lossless raw XML. Discovery mode lists a server's indexes. Pay per record.", "version": "0.1", "x-build-id": "9KjAU4aoIBQSg8bs0" }, "servers": [ { "url": "https://api.apify.com/v2" } ], "paths": { "/acts/datamule~sru-catalog-harvester/run-sync-get-dataset-items": { "post": { "operationId": "run-sync-get-dataset-items-datamule-sru-catalog-harvester", "x-openai-isConsequential": false, "summary": "Executes an Actor, waits for its completion, and returns Actor's dataset items in response.", "tags": [ "Run Actor" ], "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/inputSchema" } } } }, "parameters": [ { "name": "token", "in": "query", "required": true, "schema": { "type": "string" }, "description": "Enter your Apify token here" } ], "responses": { "200": { "description": "OK" } } } }, "/acts/datamule~sru-catalog-harvester/runs": { "post": { "operationId": "runs-sync-datamule-sru-catalog-harvester", "x-openai-isConsequential": false, "summary": "Executes an Actor and returns information about the initiated run in response.", "tags": [ "Run Actor" ], "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/inputSchema" } } } }, "parameters": [ { "name": "token", "in": "query", "required": true, "schema": { "type": "string" }, "description": "Enter your Apify token here" } ], "responses": { "200": { "description": "OK", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/runsResponseSchema" } } } } } } }, "/acts/datamule~sru-catalog-harvester/run-sync": { "post": { "operationId": "run-sync-datamule-sru-catalog-harvester", "x-openai-isConsequential": false, "summary": "Executes an Actor, waits for completion, and returns the OUTPUT from Key-value store in response.", "tags": [ "Run Actor" ], "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/inputSchema" } } } }, "parameters": [ { "name": "token", "in": "query", "required": true, "schema": { "type": "string" }, "description": "Enter your Apify token here" } ], "responses": { "200": { "description": "OK" } } } } }, "components": { "schemas": { "inputSchema": { "type": "object", "required": [ "base_url" ], "properties": { "base_url": { "title": "SRU/SRW endpoint URL", "type": "string", "description": "The base URL of any SRU (Search/Retrieve via URL) or SRW server — the Library of Congress standard protocol spoken by most national, university and union library catalogs. Examples: https://services.dnb.de/sru/dnb (German National Library), http://lx2.loc.gov:210/lcdb (Library of Congress), https://sru.k10plus.de/gvk (K10plus/GBV union catalog). One actor works against thousands of these." }, "query": { "title": "CQL query", "type": "string", "description": "A CQL (Contextual Query Language) search expression, e.g. dc.title=climate, dc.creator=goethe, or a bare keyword. The exact indexes a server supports vary — run this actor once with operation=explain to list them. Required for a searchRetrieve; ignored for explain." }, "operation": { "title": "Operation", "enum": [ "searchRetrieve", "explain" ], "type": "string", "description": "searchRetrieve (default) runs the query and returns bibliographic records. explain fetches the server's self-description and lists its searchable indexes and available record schemas — a cheap way to discover a server before querying it.", "default": "searchRetrieve" }, "recordSchema": { "title": "Record schema", "type": "string", "description": "The metadata schema to request per record. oai_dc / dc (Dublin Core) flattens to clean columns; MARC21-xml / marcxml is decoded from standard MARC tags. Any other schema still yields a structured fields map + the lossless raw XML. Leave empty to use the server's default. Common values: oai_dc, dc, marcxml, MARC21-xml, mods." }, "maximumRecords": { "title": "Records per page", "minimum": 1, "type": "integer", "description": "How many records to request per SRU page (the server's maximumRecords parameter). Most servers cap this at 100. Default 50.", "default": 50 }, "maxRecords": { "title": "Max records (global cap)", "minimum": 1, "type": "integer", "description": "A GLOBAL cap on the total number of records to harvest across all pages (each emitted record is one billable event). Leave empty to fetch a single page (equal to Records per page) — a cost-safe default. Set higher to auto-paginate through a large result set." }, "startRecord": { "title": "Start record", "minimum": 1, "type": "integer", "description": "The 1-based position of the first record to return (SRU is 1-indexed). Use to resume or skip into a result set. Default 1.", "default": 1 }, "sruVersion": { "title": "SRU version", "enum": [ "1.1", "1.2", "2.0" ], "type": "string", "description": "The SRU protocol version to send. Most servers accept 1.1; some require 1.2 or 2.0. The response is parsed the same way regardless. Default 1.1.", "default": "1.1" }, "bearer": { "title": "Bearer token", "type": "string", "description": "Optional bearer token for gated SRU deployments (sent as Authorization: Bearer ***). Not required for public library catalogs. Never logged." }, "extraHeaders": { "title": "Extra request headers", "type": "object", "description": "Optional extra HTTP headers as a JSON object, e.g. {\"x-api-key\": \"...\"} for gated servers. Not required for public servers. Header values are never logged." } } }, "runsResponseSchema": { "type": "object", "properties": { "data": { "type": "object", "properties": { "id": { "type": "string" }, "actId": { "type": "string" }, "userId": { "type": "string" }, "startedAt": { "type": "string", "format": "date-time", "example": "2025-01-08T00:00:00.000Z" }, "finishedAt": { "type": "string", "format": "date-time", "example": "2025-01-08T00:00:00.000Z" }, "status": { "type": "string", "example": "READY" }, "meta": { "type": "object", "properties": { "origin": { "type": "string", "example": "API" }, "userAgent": { "type": "string" } } }, "stats": { "type": "object", "properties": { "inputBodyLen": { "type": "integer", "example": 2000 }, "rebootCount": { "type": "integer", "example": 0 }, "restartCount": { "type": "integer", "example": 0 }, "resurrectCount": { "type": "integer", "example": 0 }, "computeUnits": { "type": "integer", "example": 0 } } }, "options": { "type": "object", "properties": { "build": { "type": "string", "example": "latest" }, "timeoutSecs": { "type": "integer", "example": 300 }, "memoryMbytes": { "type": "integer", "example": 1024 }, "diskMbytes": { "type": "integer", "example": 2048 } } }, "buildId": { "type": "string" }, "defaultKeyValueStoreId": { "type": "string" }, "defaultDatasetId": { "type": "string" }, "defaultRequestQueueId": { "type": "string" }, "buildNumber": { "type": "string", "example": "1.0.0" }, "containerUrl": { "type": "string" }, "usage": { "type": "object", "properties": { "ACTOR_COMPUTE_UNITS": { "type": "integer", "example": 0 }, "DATASET_READS": { "type": "integer", "example": 0 }, "DATASET_WRITES": { "type": "integer", "example": 0 }, "KEY_VALUE_STORE_READS": { "type": "integer", "example": 0 }, "KEY_VALUE_STORE_WRITES": { "type": "integer", "example": 1 }, "KEY_VALUE_STORE_LISTS": { "type": "integer", "example": 0 }, "REQUEST_QUEUE_READS": { "type": "integer", "example": 0 }, "REQUEST_QUEUE_WRITES": { "type": "integer", "example": 0 }, "DATA_TRANSFER_INTERNAL_GBYTES": { "type": "integer", "example": 0 }, "DATA_TRANSFER_EXTERNAL_GBYTES": { "type": "integer", "example": 0 }, "PROXY_RESIDENTIAL_TRANSFER_GBYTES": { "type": "integer", "example": 0 }, "PROXY_SERPS": { "type": "integer", "example": 0 } } }, "usageTotalUsd": { "type": "number", "example": 0.00005 }, "usageUsd": { "type": "object", "properties": { "ACTOR_COMPUTE_UNITS": { "type": "integer", "example": 0 }, "DATASET_READS": { "type": "integer", "example": 0 }, "DATASET_WRITES": { "type": "integer", "example": 0 }, "KEY_VALUE_STORE_READS": { "type": "integer", "example": 0 }, "KEY_VALUE_STORE_WRITES": { "type": "number", "example": 0.00005 }, "KEY_VALUE_STORE_LISTS": { "type": "integer", "example": 0 }, "REQUEST_QUEUE_READS": { "type": "integer", "example": 0 }, "REQUEST_QUEUE_WRITES": { "type": "integer", "example": 0 }, "DATA_TRANSFER_INTERNAL_GBYTES": { "type": "integer", "example": 0 }, "DATA_TRANSFER_EXTERNAL_GBYTES": { "type": "integer", "example": 0 }, "PROXY_RESIDENTIAL_TRANSFER_GBYTES": { "type": "integer", "example": 0 }, "PROXY_SERPS": { "type": "integer", "example": 0 } } } } } } } } } } ```