# Semantic Scholar Citation Graph Lookup

> Semantic Scholar Citation Graph Lookup is a paid API for AI agents from api.agentstools.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-10).

Returns the full citation graph for an academic paper — works it references (outgoing) and works that cite it (incoming) — along with Semantic Scholar influential-citation counts, given any standard paper identifier or title.

## Facts

- Endpoint: GET https://api.agentstools.dev/scholar/citations?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/semantic-scholar-citation-graph-lookup-7bd05b24
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4GqHInRhzWYI_mSYlNPOB

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability semantic-scholar-citation-graph-lookup-7bd05b24
```

Example prompt: Can you pull the full citation graph for the paper with arXiv ID 2401.01234 — I want to see both what it references and what papers have cited it, up to 25 results each way?

## When to prefer this

Use this endpoint when you need structured, normalized citation data for a specific academic paper identified by DOI, arXiv ID, PMID, PMC ID, OpenAlex ID, or title. It is ideal for literature review automation, prior-art mapping, and citation network analysis. Prefer it over manual Semantic Scholar web scraping or full-text search endpoints when you already have a paper identifier and need its citation relationships.

## Known failure modes

- Paper identifier not found in Semantic Scholar — returns empty or error if DOI/arXiv/PMID is invalid or not indexed
- Title search ambiguity — if the title matches multiple papers, wrong paper may be resolved
- Rate limiting or payment failure — 402 response if x402 payment is not processed
- No citations found — paper exists but has zero references or citations in the database
- Malformed identifier — unrecognized format for doi/arxiv/pmid returns validation error

## How this service works

Citation graph of a paper: the works it references (outgoing) and the works that cite it (incoming), each as normalized records, plus the Semantic Scholar influential-citation count. Give a doi, arxiv, pmid, openalex_id or title. Ideal for literature review and prior-art mapping.

## Output

A structured citation graph object containing: (1) a list of outgoing references (works this paper cites), (2) a list of incoming citations (works that cite this paper), each as normalized records with title, authors, year, venue, and identifiers, plus the Semantic Scholar influential-citation count for the paper.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "id": {
       "type": "string",
       "description": "Any single identifier; its type is auto-detected"
      },
      "doi": {
       "type": "string",
       "description": "DOI, with or without a doi.org prefix"
      },
      "pmid": {
       "type": "string",
       "description": "PubMed id (digits)"
      },
      "arxiv": {
       "type": "string",
       "description": "arXiv id such as 2401.01234"
      },
      "limit": {
       "type": "integer",
       "maximum": 50,
       "minimum": 1,
       "description": "Max items to return, default 10"
      },
      "pmcid": {
       "type": "string",
       "description": "PubMed Central id such as PMC1234567"
      },
      "title": {
       "type": "string",
       "description": "Paper title to resolve by search"
      },
      "openalex_id": {
       "type": "string",
       "description": "OpenAlex work id such as W2741809807"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/semantic-scholar-citation-graph-lookup-7bd05b24/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.agentstools.dev](https://www.zero.xyz/host/api.agentstools.dev/llms.txt)