semble
★ 4.5k
vs
pctx
★ 258
semble vs pctx
semble: Semble is a high-performance code search library designed for AI agents, providing instant access to precise code snippets. It offers significantly faster indexing and querying compared to transformer models, achieving 99% of their retrieval quality while running entirely on CPU without external dependencies.; pctx: pctx sits between AI agents and MCP servers, aggregating multiple upstream MCP servers, handling authentication, and exposing tools through a unified Code Mode interface. It replaces sequential tool calling with code execution, resulting in significant token reduction. It supports multiple installation methods and provides Python SDK for agent development.
01
TL;DR
Choose semble if…Enhancing AI agents (e.g., Claude Code, Cursor, Codex) with fast and accurate code search capabilities
Choose pctx if…Building AI agents that need to interact with multiple MCP servers efficiently
02
Side-by-Side Comparison
03
Features
semble01Fast performance on CPU (indexes in ~250ms, queries in ~1.5ms)
02High accuracy (NDCG@10 of 0.854), comparable to transformer models
03Supports indexing local paths and remote Git repositories
04Functions as an MCP server for various AI agents
05Zero setup, no API keys, GPU, or external services required
pctx01Code Mode interface: tools exposed as code functions for efficient agent interaction
02Upstream MCP server aggregation: connect to multiple MCP servers through a single interface
03Simple config with CLI: create pctx.json config with a simple CLI
04Secure authentication: source secrets from environment variables, system keychain, and external commands
04
Use Cases
semble↳Enhancing AI agents (e.g., Claude Code, Cursor, Codex) with fast and accurate code search capabilities
↳Searching local or remote codebases for specific code snippets based on natural language or code queries
↳Finding semantically similar code sections related to a given file path and line number
pctx↳Building AI agents that need to interact with multiple MCP servers efficiently
↳Running Code Mode sessions for complex multi-step operations with token reduction
↳Using as a unified MCP server for authentication and tool aggregation
05
Best For
sembleCode AssistantRAG / Knowledge Base
pctxTrendingWorkflow AutomationSecurity & Safety
FAQ
FAQ
What is the difference between semble and pctx?
Both semble and pctx are in the RAG / Knowledge Base category. semble has 4.5k stars, while pctx has 258 stars.
Which is better, semble or pctx?
The best choice depends on your use case. Choose semble if Enhancing AI agents (e.g., Claude Code, Cursor, Codex) with fast and accurate code search capabilities, and pctx if Building AI agents that need to interact with multiple MCP servers efficiently.
Is semble free or open source?
Yes, semble is open source on GitHub (MIT).
Is pctx free or open source?
Yes, pctx is open source on GitHub (MIT).
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