@contextstream/mcp-server

ContextStream MCP Server

Your AI coding assistant finally has a memory.

ContextStream gives your AI tools persistent context across sessions, semantic code search, and team knowledge sharing. Every decision, preference, and lesson learned is captured and surfaced when relevant.

npx -y @contextstream/mcp-server setup

Works with Cursor, Antigravity, Claude Code, Windsurf, VS Code, Claude Desktop, Codex CLI, and more.

The Problem

Without ContextStream, every AI conversation starts from scratch:

• "We decided to use PostgreSQL" — forgotten next session
• "Don't use that deprecated API" — your AI suggests it anyway
• "Here's how our auth flow works" — explained for the 10th time
• Team decisions live in Slack threads no one can find

The Solution

ContextStream creates a shared brain for your AI assistant:

What you get	How it works
Persistent Memory	Decisions, preferences, and notes survive across sessions
Semantic Code Search	Find code by meaning, not just keywords
Team Knowledge	Share context across your team's AI tools
Integration Sync	Pull context from GitHub, Slack, and Notion automatically
Smart Context	Your AI gets relevant context for every message

See It In Action

You say... → ContextStream does...

Prompt	What happens
"What did we decide about auth?"	Finds the decision from 3 weeks ago
"Remember we're using PostgreSQL"	Captured for all future sessions
"Search for payment handling code"	Semantic search across your codebase
"What depends on UserService?"	Analyzes dependency graph and impact
"Show me recent GitHub activity"	Surfaces issues, PRs, and discussions
"What's in our API docs on Notion?"	Searches your Notion knowledge base

No special commands needed. Just describe what you want.

Quick Setup (30 seconds)

The setup wizard handles everything:

npx -y @contextstream/mcp-server setup

This will:

• Authenticate your account (opens browser)
• Create and store your API key
• Install editor rules for best results
• Configure your AI tools automatically
• Install Claude Code hooks (optional, recommended)

That's it. Start a conversation and your AI now has memory.

What Gets Captured

ContextStream automatically tracks:

Type	Examples
Decisions	"We chose JWT over sessions", "Using Tailwind for styling"
Preferences	"I prefer functional components", "Always use TypeScript"
Lessons	"That approach caused a memory leak", "This pattern works well"
Tasks	Implementation plans, TODOs, follow-ups
Code Context	File relationships, dependencies, patterns

Everything is searchable by meaning, not just keywords.

Integrations

Connect your team's tools to enrich AI context automatically:

GitHub

• Issues, PRs, releases, and comments synced as searchable memory
• "What's the status of the auth refactor?" finds the relevant PR
• Decisions from issue discussions surface when relevant

Slack

• Channel discussions become searchable knowledge
• Team decisions captured from conversations
• "What did we discuss about the API?" finds the thread

Notion

• Documentation and wikis become AI context
• Smart type detection for tasks, meetings, bugs, features
• "How does our deployment process work?" finds the runbook

Team Features

ContextStream shines for teams:

• Shared workspace memory — decisions made by anyone benefit everyone
• Onboarding acceleration — new team members get full context from day one
• Knowledge preservation — context survives when people leave
• Consistent AI behavior — everyone's AI knows the same preferences

Smarter Context, Fewer Tokens

AI tools typically gather context by reading entire files, running grep searches, and iterating until they find what they need. This burns through your token budget fast.

ContextStream takes a different approach:

Bounded retrieval — context_smart returns only the context relevant to your current message, within a strict token budget. Instead of reading 10 files to find one decision, you get exactly what matters.

Semantic search — Find code by meaning in a single query. No more grep "auth" → read file → grep "middleware" → read another file loops. One search, relevant results.

Smart output formats — Choose the verbosity you need:

• Need file locations? Use paths format (80% smaller responses)
• Just checking if something exists? Use count format (90% smaller)
• Need full context? Use full format

AI-powered compression — For complex queries, Context Pack distills large code contexts into compact, high-signal summaries that preserve file paths, line numbers, and essential snippets.

The result: your AI gets better context while using fewer tokens. Faster responses, lower costs, and more room in the context window for actual work.

Core Tools

Your AI uses these automatically:

Tool	Purpose
session_init	Load workspace/project context at conversation start
context_smart	Get relevant context for each message
search	Semantic, hybrid, or keyword search across everything
session	Capture and recall decisions, preferences, lessons
memory	Create and manage knowledge nodes
graph	Analyze code dependencies and impact
integration	Query GitHub, Slack, Notion directly

Full tool reference: https://contextstream.io/docs/mcp/tools

Manual Configuration

Skip this if you used the setup wizard.

Cursor / Windsurf / Claude Desktop

Add to your MCP config:

{
  "mcpServers": {
    "contextstream": {
      "command": "npx",
      "args": ["-y", "@contextstream/mcp-server"],
      "env": {
        "CONTEXTSTREAM_API_KEY": "YOUR_API_KEY"
      }
    }
  }
}

Config locations:

• Cursor: ~/.cursor/mcp.json
• Windsurf: ~/.codeium/windsurf/mcp_config.json
• Claude Desktop (macOS): ~/Library/Application Support/Claude/claude_desktop_config.json

Claude Code (CLI)

claude mcp add --transport stdio contextstream --scope user \
  --env CONTEXTSTREAM_API_KEY=YOUR_KEY \
  -- npx -y @contextstream/mcp-server

Claude Code Hooks (Recommended)

ContextStream can install hooks that enforce best practices:

• PreToolUse hook — Redirects Glob/Grep/Search to ContextStream semantic search
• UserPromptSubmit hook — Injects context reminders every message

Install hooks automatically when generating rules:

npx -y @contextstream/mcp-server setup
# Or: mcp__contextstream__generate_rules(editors=["claude"])

Hooks are installed to ~/.claude/hooks/ and configured in ~/.claude/settings.json. Your custom rules are preserved — only ContextStream blocks are updated.

VS Code

Add to .vscode/mcp.json:

{
  "servers": {
    "contextstream": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@contextstream/mcp-server"],
      "env": {
        "CONTEXTSTREAM_API_KEY": "${input:contextstreamApiKey}"
      }
    }
  },
  "inputs": [
    {
      "id": "contextstreamApiKey",
      "type": "promptString",
      "description": "ContextStream API Key",
      "password": true
    }
  ]
}

Codex CLI

Add to ~/.codex/config.toml:

[mcp_servers.contextstream]
command = "npx"
args = ["-y", "@contextstream/mcp-server"]

[mcp_servers.contextstream.env]
CONTEXTSTREAM_API_KEY = "YOUR_API_KEY"

Environment Variables

Variable	Description
CONTEXTSTREAM_API_KEY	Your API key (required)
CONTEXTSTREAM_API_URL	API endpoint (default: https://api.contextstream.io)
CONTEXTSTREAM_WORKSPACE_ID	Default workspace
CONTEXTSTREAM_PROJECT_ID	Default project
CONTEXTSTREAM_SEARCH_REMINDER	Set to false to disable search-first reminders
CONTEXTSTREAM_HOOK_ENABLED	Set to false to disable hooks without uninstalling

Troubleshooting

Issue	Solution
Tools not appearing	Restart your editor after config changes
401 Unauthorized	Check your API key is correct
Wrong workspace	Run session_init or re-run the setup wizard

Links

Resource	URL
Website	https://contextstream.io
Documentation	https://contextstream.io/docs
Tool Reference	https://contextstream.io/docs/mcp/tools
Pricing	https://contextstream.io/pricing

License

MIT