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Caesar API

Alt text

Give your application the ability to research anything.

Caesar is an agentic research API that transforms questions into comprehensive, citation-backed answers. Unlike traditional search APIs that return links, Caesar reads, reasons, and synthesizes, delivering expert-level research in seconds.

Explore the API

Get your API key

See it in action

Create a research job
$curl -X POST https://api.caesar.xyz/research \
>  -H "Authorization: Bearer YOUR_API_KEY" \
>  -H "Content-Type: application/json" \
>  -d '{"query": "What are the leading approaches to nuclear fusion?", "auto": true}'
Response with citations
1{
2  "id": "res_7f3a2b1c",
3  "status": "completed",
4  "reasoning_loops_consumed": 2,
5  "running_time": 34,
6  "content": "Nuclear fusion research is advancing through several key approaches...\n\n**Magnetic Confinement (Tokamaks)**\nThe ITER project [1] represents the largest tokamak...\n\n**Inertial Confinement**\nThe National Ignition Facility achieved ignition in December 2022 [2]...",
7  "results": [
8    {
9      "title": "ITER - the way to new energy",
10      "url": "https://www.iter.org/",
11      "citation_index": 1
12    },
13    {
14      "title": "National Ignition Facility Achieves Fusion Ignition",
15      "url": "https://www.llnl.gov/news/...",
16      "citation_index": 2
17    }
18  ]
19}

Every response includes numbered citations linking to source URLs. Your users can verify any claim.

Why Caesar?

Traditional search APIs return links. RAG systems retrieve chunks. Caesar does something different: it researches.

ApproachWhat you get
Search APIs10 blue links to sort through
RAGRetrieved chunks, often lacking context
LLMsAnswers with no sources, potential hallucinations
CaesarSynthesized research with live sources and citations
Real-time knowledge

Every query searches live sources. No stale training data, no knowledge cutoffs. Ask about today’s news or last week’s research papers.

Agentic reasoning

Caesar doesn’t just retrieve. It analyzes, identifies gaps, formulates follow-up queries, and iteratively builds understanding.

How it works

Caesar uses an agentic research loop that mirrors how expert researchers work:

1

Analyze

Parses your question to understand intent and identify key concepts.

2

Gather

Searches web, academic databases, news, and financial data. Reads and extracts relevant content.

3

Evaluate

Identifies knowledge gaps. If critical information is missing, formulates follow-up queries.

4

Iterate

Repeats the cycle (controlled by reasoning_loops) until thoroughly answered.

5

Synthesize

Combines findings into a coherent, cited response.

Control research depth
1{
2  "query": "Comprehensive analysis of quantum computing applications in drug discovery",
3  "reasoning_loops": 5,
4  "reasoning_mode": true,
5  "exclude_social": true
6}

Use auto: true to let Caesar automatically configure parameters based on your query complexity.

Quick start

1. Get your API key

Create an API key in your dashboard. Keys start with csk- and should be kept secret.

2. Make your first request

$curl -X POST https://api.caesar.xyz/research \
>  -H "Authorization: Bearer YOUR_API_KEY" \
>  -H "Content-Type: application/json" \
>  -d '{"query": "What companies are leading in solid-state battery development?", "auto": true}'

3. Retrieve results

Research jobs run asynchronously. Poll for completion or stream results:

Poll for results
$curl https://api.caesar.xyz/research/{job_id} \
>  -H "Authorization: Bearer YOUR_API_KEY"
Or stream as results arrive
$curl https://api.caesar.xyz/research/{job_id}/events \
>  -H "Authorization: Bearer YOUR_API_KEY" \
>  -H "Accept: text/event-stream"

Use cases

Use caseExample queryRecommended config
Quick lookups”Apple Q3 2024 revenue”reasoning_loops: 1
Comparative analysis”Compare React vs Vue for enterprise apps”reasoning_loops: 3
Deep research”Systematic review of CRISPR applications in oncology”reasoning_loops: 5, reasoning_mode: true
Technical due diligence”Architecture and scaling challenges of company X”reasoning_loops: 4, exclude_social: true

Integration options

Choose how you want to integrate:

Full access to all features: research parameters, file uploads, collections, and streaming.

$curl -X POST https://api.caesar.xyz/research \
>  -H "Authorization: Bearer YOUR_API_KEY" \
>  -d '{"query": "...", "reasoning_loops": 3}'
View API Reference

Key concepts

Control depth with reasoning_loops (1-10), model quality with reasoning_mode, and source filtering with exclude_social. Or use auto: true to let Caesar optimize.

Learn more →

Upload PDFs and documents, then include them in research. Caesar combines your files with live web research.

Learn more →

Shape output format. Get responses as JSON, bullet points, executive summaries, or custom structures.

Learn more →

Get results via Server-Sent Events as they’re generated. Show progress and reduce perceived latency.

Learn more →

Next steps

API Reference

Explore all endpoints

Research Parameters

Fine-tune research depth

Rate Limits

Understand usage limits

Need help? Contact us at support@caesar.xyz