GitHub - cioffiAI/mcp-agora: MCP Server with cross-agent persistent memory for AI agent fleets. Vector memory (ChromaDB), semantic search, in-memory cache, backend routing, and shared knowledge across AI agents.

MCP Server with cross-agent persistent memory for AI agent fleets.

Agora is a local, Python-only MCP server that gives your AI agents (Claude Code, Codex, ChatGPT, Gemini CLI) a shared persistent memory. Knowledge saved by one agent is immediately available to all others — no more repeating work, no more isolated sessions.

uv run agora

Features

Phase 1 — Core Memory

agora_save — Save knowledge with semantic embeddings (tags optional)
agora_query — Semantic search across all saved knowledge (top-k results)
agora_status — Server stats: memory count, agents, cache, backends, health, DB size
Persistent ChromaDB storage (data survives restarts)
L1 in-memory cache (TTLCache, 1000 entries, 5min TTL, full-param SHA-256 cache key)
Cache invalidation on save (clear-all L1+L2, safe strategy)
Fully local embeddings (sentence-transformers all-MiniLM-L6-v2, 384d, no API key)
Background warmup (model loads in daemon thread, server starts instantly)
WarmingUpError grace (tools return friendly message if model not yet loaded)

Phase 2 — Routing & Backend Connectors

agora_route — Route tool calls to external MCP servers by name or semantic match
agora_broadcast — Call a tool on ALL backends in parallel via asyncio.gather
agora_backends — List configured backends with connection status
Semantic router — Routes to backends via cosine similarity on description embeddings (threshold >= 0.5)
Exact-name router — Case-insensitive exact match tried first, falls back to semantic
STDIO connector — Subprocess MCP client via stdio_client + ClientSession, lazy connection on first use
HTTP connector — Streamable HTTP MCP client for remote servers
BackendRegistry — Lifecycle management: register from config, lazy connect, disconnect_all on shutdown
Config-driven backends — Declare external MCP servers in config.yaml with env var expansion (${GITHUB_TOKEN})
GitHub MCP — Pre-configured: issues, PRs, repos, code search, commits
Playwright MCP — Pre-configured: browser automation (navigate, click, screenshot), read_only

Phase 3 — Cross-agent Memory

agora_crossref — Cross-reference entries by query or entry_id (groups by agent)
agora_forget — Delete entries by ID, tags, or agent (supports dry_run)
SQLite provenance — Who saved what, when, with what confidence
L2 persistent cache — SQLite-backed, 24h TTL, survives restarts
3-tier cache cascade — L1 (TTLCache) → L2 (SQLite) → ChromaDB

Phase 4 — Robustness

Health check — Backend health monitoring (healthy/unhealthy/dead with 3-failure threshold)
Configurable retry — Per-backend max_retries + retry_delay
Rate limiting — Per-backend rate_limit_rps to prevent API abuse
Structured logging — File-based logging to ~/.agora/logs/agora.log (configurable via LOG_LEVEL)
Non-blocking startup — Background warmup thread + WarmingUpError grace on embedding-dependent tools
6 graceful degradation tests — Backend failure, health cascade, retry, rate limit
61 tests across 10 files, all passing

Phase 5 — Portfolio Polish

Feature	Status
Quickstart in 3 comandi	✅ One-liner install (`curl \| sh` / `iwr \| iex`)
Config YAML fully commented	✅ Every field explained
Install scripts	✅ `scripts/install.ps1` + `scripts/install.sh`
GitHub Actions CI	✅ Test + lint on push/PR (Ubuntu + Windows)
GitHub release	✅ v0.4.0 with changelog
PyPI publication	✅ `pip install mcp-agora`
SVG architecture diagram	✅ `docs/architecture_en.svg` + `docs/architecture_it.svg`

Architecture

Quickstart

One-liner install

# Unix (Linux / macOS)
curl -fsSL https://raw.githubusercontent.com/cioffiAI/mcp-agora/main/scripts/install.sh | sh

# Windows (PowerShell)
iwr -useb https://raw.githubusercontent.com/cioffiAI/mcp-agora/main/scripts/install.ps1 | iex

Manual install

# Prerequisites: Python 3.13+ and uv 0.11+
#   Unix:  curl -LsSf https://astral.sh/uv/install.sh | sh
#   Windows: irm https://astral.sh/uv/install.ps1 | iex

# Install from PyPI
uv tool install mcp-agora

# Run
agora

From source

git clone https://github.com/cioffiAI/mcp-agora.git
cd mcp-agora
uv run agora

Configure as MCP Server

Add to your MCP host config (e.g. opencode.jsonc):

Note: Requires uv tool install mcp-agora first. The agora tool finds ~/.agora/config.yaml automatically. Copy your config there to customize backends, or use AGORA_CONFIG=/path/to/config.yaml.

Usage

# Save knowledge
uv run python -c "
from agora.server import create_server
"  # or use via MCP tools in your agent

Via MCP tools (in any MCP-compatible agent):

Save:

Call tool: agora_save
  content: "PostgreSQL BRIN indexes are useful for very large tables with correlated data"
  tags: ["postgres", "sql", "performance"]
→ { "saved": true, "id": "mem_20260505_..." }

Query:

Call tool: agora_query
  query: "PostgreSQL indexing performance"
  top_k: 5
→ { "query": "...", "results": [...], "cached": false }

Status:

Call tool: agora_status
→ { "server": "Agora", "memory_entries": 42, "cache_stats": {...}, "backends": {...} }

Route to backend:

Call tool: agora_route
  target: "github"
  tool: "github_search_repositories"
  arguments: { "query": "mcp server" }
→ { "target": "github", "matched_by": "exact_name", "result": { "items": [...] } }

List backends:

Call tool: agora_backends
→ { "backends": [{ "name": "github", "connected": false, "tool_count": 15, ... }] }

Configuration

Default config.yaml (v0.4.0):

agora:
  name: "Agora"
  version: "0.4.0"

storage:
  chroma_path: "~/.agora/chroma"
  db_path: "~/.agora/agora.db"

cache:
  l1_max_entries: 1000
  l1_ttl_seconds: 300
  l2_max_entries: 10000
  l2_ttl_seconds: 86400

embedding:
  provider: "sentence-transformers"
  model: "all-MiniLM-L6-v2"

backends:
  - name: "github"
    transport: "stdio"
    command: ["npx", "-y", "@modelcontextprotocol/server-github"]
    description: "GitHub API: issues, PRs, repos, code search, commits"
    read_only: false
    timeout_seconds: 15
    max_retries: 3
    retry_delay: 1.0
    rate_limit_rps: 5
    env:
      GITHUB_TOKEN: "${GITHUB_TOKEN}"
  - name: "playwright"
    transport: "stdio"
    command: ["npx", "@playwright/mcp@latest"]
    description: "Browser automation: navigate, click, screenshot, forms"
    read_only: true
    timeout_seconds: 30
    max_retries: 2
    retry_delay: 0.5
    rate_limit_rps: 2

Override config path: AGORA_CONFIG=/path/to/config.yaml agora

Testing

# All tests
uv run pytest tests/ -v

# Single test
uv run pytest tests/test_cache.py -v -k "test_hit_count"

# MCP smoke tests (real STDIO subprocess)
uv run pytest tests/test_mcp_smoke.py -v

61 tests across 10 files:

File	Count	Scope
`test_embedding.py`	3	Dimension, vector format, document retrieval order
`test_memory.py`	5	ChromaDB add, query, delete, multiple docs, integration
`test_cache.py`	5	TTLCache set, get, expiry, hit_count, clear
`test_l2_cache.py`	7	L2 SQLite set, get, expiry, hit_count, stats, clear, prune
`test_provenance.py`	7	Agent registry, provenance add/get/list/delete
`test_protocol.py`	6	FastMCP tool wiring, save→query, cache hit, provenance
`test_routing.py`	9	Cosine similarity, exact/semantic/no match, warmup
`test_connectors.py`	8	Properties, health, disconnect, read-only enforcement
`test_graceful.py`	6	Backend failure, health cascade, retry, rate limit
`test_mcp_smoke.py`	5	Full smoke, multiple entries, stress, routing, status

Project Structure

mcp-agora/
├── pyproject.toml              # Dependencies, build config, entry point
├── config.yaml                 # Server configuration (incl. backends)
├── README.md                   # This file
├── AGENTS.md                   # Agent-facing instructions
├── ARCHITECTURE.md             # Full architecture, rationale, risk analysis
├── agora/
│   ├── main.py                 # Entry point: `agora` command
│   ├── server.py               # FastMCP server + tool registration
│   ├── config.py               # YAML config loader (incl. BackendConfig)
│   ├── logging.py              # File-based structured logging
│   ├── registry.py             # BackendRegistry (lifecycle, lazy connect)
│   ├── connectors/
│   │   ├── __init__.py
│   │   ├── base.py             # BackendConnector ABC + ReadOnlyBlockedError
│   │   ├── stdio.py            # STDIO subprocess MCP client
│   │   └── http.py             # Streamable HTTP MCP client
│   ├── routing/
│   │   └── router.py           # Semantic + exact name router
│   ├── embedding/
│   │   ├── base.py             # Abstract EmbeddingProvider + WarmingUpError
│   │   └── sentence.py         # sentence-transformers wrapper
│   ├── memory/
│   │   └── vector_store.py     # ChromaDB PersistentClient wrapper
│   ├── cache/
│   │   ├── l1_memory.py        # TTLCache in-memory
│   │   └── l2_cache.py         # SQLite-backed persistent cache
│   └── db/
│       └── database.py         # SQLite: agents, provenance, L2 cache
├── tests/
│   ├── test_embedding.py
│   ├── test_memory.py
│   ├── test_cache.py
│   ├── test_l2_cache.py
│   ├── test_provenance.py
│   ├── test_protocol.py
│   ├── test_routing.py
│   ├── test_connectors.py
│   ├── test_graceful.py
│   ├── test_mcp_smoke.py
│   └── _echo_server.py         # Minimal FastMCP echo server for tests
└── examples/
    └── config.yaml.example

Stack

Component	Technology
Runtime	Python 3.13+, uv 0.11+
MCP Framework	FastMCP (mcp SDK ≥1.0.0)
Vector Store	ChromaDB (PersistentClient, HNSW index)
Embeddings	sentence-transformers all-MiniLM-L6-v2 (384d), lazy-load + background warmup
Cache L1	cachetools TTLCache (1k entries, 5min TTL)
Cache L2	SQLite (10k entries, 24h TTL)
Provenance	SQLite (agents, entry provenance)
Config	PyYAML (env var expansion `$VAR`)
Testing	pytest, pytest-asyncio

License

MIT

推荐订阅源

Hacker News - Newest: "AI"

Features

Features

Phase 1 — Core Memory

Phase 2 — Routing & Backend Connectors

Phase 3 — Cross-agent Memory

Phase 4 — Robustness

Phase 5 — Portfolio Polish

Architecture

Quickstart

One-liner install

Manual install

From source

Configure as MCP Server

Usage

Configuration

Testing

Project Structure

Stack

License