Exa Semantic Search

Overview

Exa.ai provides neural semantic search optimized for AI consumption. Use when meaning matters more than keywords.

Decision Flowchart

digraph exa_decision { rankdir=TB; node [shape=box];

start [label="Need to search the web?" shape=diamond];
known_url [label="Do you have\na specific URL?" shape=diamond];
semantic [label="Is this semantic/conceptual?\n(meaning > keywords)" shape=diamond];
recent [label="Need very recent\nnews/events?" shape=diamond];
code [label="Is this a coding/\nAPI question?" shape=diamond];

webfetch [label="WebFetch" shape=box style=filled fillcolor=lightblue];
websearch [label="WebSearch" shape=box style=filled fillcolor=lightgreen];
exa_web [label="mcp__exa__web_search_exa" shape=box style=filled fillcolor=lightyellow];
exa_code [label="mcp__exa__get_code_context_exa" shape=box style=filled fillcolor=lightyellow];

start -> known_url [label="yes"];
start -> known_url [label="no" style=invis];
known_url -> webfetch [label="yes"];
known_url -> semantic [label="no"];
semantic -> code [label="yes"];
semantic -> recent [label="no"];
code -> exa_code [label="yes"];
code -> exa_web [label="no"];
recent -> websearch [label="yes"];
recent -> websearch [label="no"];

}

Quick Reference

Scenario Tool Why

"Find papers on emergent AI behavior" mcp__exa__web_search_exa

Semantic discovery

"Companies similar to Anthropic" mcp__exa__web_search_exa

Similar content

"How to use React hooks" mcp__exa__get_code_context_exa

Coding context

"Latest news on X" WebSearch

Recency matters

"Read this URL: [link]" WebFetch

Known URL

"error: module not found XYZ" WebSearch

Exact keyword match

"CVE-2024-12345" WebSearch

Specific identifier

Tool Usage

mcp__exa__web_search_exa

query: "semantic query describing concepts" numResults: 8 (default, adjust as needed) type: "auto" | "fast" | "deep"

mcp__exa__get_code_context_exa

query: "React useState hook examples" | "Express middleware patterns" tokensNum: 5000 (default, 1000-50000 range)

Integration Patterns

Discovery + Extraction:

• Exa finds relevant sources semantically

• WebFetch extracts full content from best URLs

Multi-perspective research:

• Exa: "academic perspectives on X"

• Exa: "industry implementation of X"

• Exa: "critiques of X"

• Synthesize

Fallback:

• Try Exa for semantic search

• If results poor, fall back to WebSearch with keywords

Anti-Patterns

Don't Do Instead

"python pandas filter dataframe"

Use WebSearch (keyword query)

Run 10 similar queries Consolidate into 2-3 well-crafted queries

"what is React"

Use knowledge or WebSearch

"breaking news today"

Use WebSearch

When Results Are Poor

• Switch search type: auto vs fast vs deep

• Rephrase: more semantic/descriptive

• Add domain filters via allowed_domains

• Fall back to WebSearch for keyword matching