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HAL Open Archive SPARQL SELECT Query (dataHAL)

halsparql/sparql-query

Runs a read-only SPARQL SELECT query against dataHAL, the linked-data service of the HAL open archive (research papers, theses and conference papers from French and international institutions, run by the CCSD). The query must start with optional PREFIX lines then SELECT, must end with LIMIT n (1 to 999), and may not use SERVICE; it is cut off after 20 seconds. Returns the SPARQL JSON results document. Class prefix: fabio: is http://purl.org/spar/fabio/ (fabio:Article, fabio:ConferencePaper, fabio:Chapter, fabio:DoctoralThesis); titles are dcterms:title. The service answers at data.hal.science/sparql (the older data.archives-ouvertes.fr/sparql address redirects there). HAL data, served by Eden Engine; not an official HAL or CCSD product.

activeper callv1

Price

$0.0026 per call

You pay the price shown. If a call turns out to cost more than its quote, you pay the actual price, capped at twice the quote. No monthly minimum. Top-ups start at $0.50.

Data source

HAL (CCSD)

Data from HAL, the French open archive of the Centre pour la Communication Scientifique Directe (CCSD), via dataHAL (data.hal.science). Served by Eden Engine; not an official HAL or CCSD product.

Use it

Five steps: search, inspect, learn, run, settle. No per-tool setup; your agent reaches this tool through the meta-tools it already has.

Connect once and your AI can find and run this tool, and any other it needs.

Install itCreate an account
agent
// 1. search: find the tool
omnial_search({ query: "what you need" })

// 2. inspect: price and input schema
omnial_inspect({ tool: "halsparql/sparql-query" })

// 3. learn: read the usage guide at runtime
omnial_learn({ tool: "halsparql/sparql-query" })

// 4. run: price the exact call first, then run it
omnial_execute({ tool: "halsparql/sparql-query", input: { /* see input_schema */ }, dry_run: true })
omnial_execute({ tool: "halsparql/sparql-query", input: { /* ... */ } })

// 5. settle: the call is charged when it finishes, nothing to do

Not connected yet? Point your MCP client at https://mcp.eden-engine.com/mcp, then copy a config for your client.

Pricing

Every charge this tool can incur.

ChargePrice
Per call
$0.0026
Updated
Oct 24, 2026

Input and output schemas

Input schema
input_schema.json
{
  "type": "object",
  "required": [
    "query"
  ],
  "properties": {
    "query": {
      "type": "string",
      "pattern": "^(?![\\s\\S]*\\b[Ss][Ee][Rr][Vv][Ii][Cc][Ee]\\b)(PREFIX [A-Za-z0-9_]*: <[^>\\s]*> ?)*SELECT [^;]*LIMIT [0-9]{1,3}$",
      "maxLength": 2000,
      "minLength": 20,
      "description": "SPARQL SELECT, up to 2000 characters, optional PREFIX lines first, ending with LIMIT and a number up to 999. For example: PREFIX fabio: <http://purl.org/spar/fabio/> SELECT ?t (COUNT(?d) AS ?n) WHERE { ?d a ?t } GROUP BY ?t LIMIT 20"
    }
  },
  "additionalProperties": false
}
Output schema
output_schema.json
{
  "type": "object",
  "required": [
    "head",
    "results"
  ],
  "properties": {
    "head": {
      "type": "object",
      "properties": {
        "vars": {
          "type": "array",
          "items": {
            "type": "string"
          }
        }
      },
      "additionalProperties": true
    },
    "results": {
      "type": "object",
      "required": [
        "bindings"
      ],
      "properties": {
        "bindings": {
          "type": "array",
          "items": {
            "type": "object",
            "additionalProperties": true
          },
          "description": "One object per result row; each variable maps to {type, value} plus xml:lang or datatype where the value has one."
        }
      },
      "additionalProperties": true
    }
  },
  "description": "The SPARQL 1.1 JSON results document.",
  "additionalProperties": true
}