OpenRouter Agents MCP Server

Production MCP server for multi-agent AI research. Plan, parallelize, synthesize.

Install

npx @terminals-tech/openrouter-agents --stdio

Claude Code one-liner:

claude mcp add openrouter-agents -- npx @terminals-tech/openrouter-agents --stdio

What's New (v2.0.0)

• MCP SDK 1.27.1 — registerTool/registerPrompt/registerResource APIs, security fixes
• Zod 4 — Upgraded from Zod 3; z.record() syntax, config schema fixes
• Express 5 — Upgraded from Express 4; modern path patterns, req.query handling
• Streamable HTTP — Primary transport (SSE deprecated as legacy fallback)
• Circuit breaker — Model API fault tolerance with configurable thresholds
• Embedding-based model routing — Local vector similarity for model selection (no LLM call)
• Persistent storage — Reports, jobs, knowledge graph persist across sessions by default

macOS/Node 25 Note: A cosmetic libc++abi: mutex lock failed message may appear on shutdown. This is harmless — data is checkpointed before shutdown. Set DBAUTOHEAL=true for in-memory mode (no persistence, no message).

Full Changelog | Extensions Guide | MCP Compliance Report

Configuration

Set OPENROUTERAPIKEY in your environment, then configure via .env or .mcp.json:

| Variable | Default | Description | |----------|---------|-------------| | OPENROUTERAPIKEY | required | OpenRouter API key | | OPENROUTERAPIKEYS | (optional) | Comma-separated OpenRouter keys for rotation | | OPENROUTERKEYCOOLDOWN_MS | 5000 | Base cooldown per key after failures | | SERVER_PORT | 3002 | HTTP server port | | MODE | ALL | AGENT, MANUAL, or ALL | | EMBEDDINGROUTINGENABLED | true | Enable embedding-based model routing | | INDEXER_ENABLED | true | Enable knowledge indexing |

Full ENV Reference

{
  "mcpServers": {
    "openrouter-agents": {
      "command": "npx",
      "args": ["@terminals-tech/openrouter-agents", "--stdio"],
      "env": {
        "OPENROUTERAPIKEY": "${OPENROUTERAPIKEY}",
        "INDEXER_ENABLED": "true"
      }
    }
  }
}

Multi-Client Setup

Transport Modes

| Transport | Flag | Use Case | |-----------|------|----------| | STDIO | (default) | MCP clients (Claude, Jan AI, Continue) | | HTTP | --http | Web apps, shared server |

STDIO is the default transport per MCP spec. Use --http explicitly for HTTP mode.

Client-Specific Setup

{
  "mcpServers": {
    "openrouter-agents": {
      "command": "npx",
      "args": ["@terminals-tech/openrouter-agents"],
      "env": {
        "OPENROUTERAPIKEY": "sk-or-..."
      }
    }
  }
}

{   "command": "npx",   "args": ["@terminals-tech/openrouter-agents"],   "env": { "OPENROUTERAPIKEY": "..." } }

Feature Matrix

| Feature | All MCP Clients | Claude Code Only | |---------|-----------------|------------------| | Core Research Tools | ✓ | ✓ | | Knowledge Base | ✓ | ✓ | | Session/Graph Tools | ✓ | ✓ | | Rail Protocol Tools | ✓ | ✓ | | Slash Commands | - | ✓ |

Models (v2.0.0)

High-Cost Tier

Low-Cost Tier

Models are selected via embedding-based routing — query embeddings are matched to model domain profiles without an LLM call.

Tools

MCP Compliance

Compliant with MCP Specification 2025-11-25 (stable, AAIF/Linux Foundation governance).

| Feature | SEP | Status | |---------|-----|--------| | JSON-RPC 2.0 | Core | Compliant | | Tools/Resources/Prompts | Core | Compliant | | Task Protocol | SEP-1686 | Compliant | | Sampling with Tools | SEP-1577 | Compliant | | Elicitation | SEP-1036 | Compliant | | MCP Apps | SEP-1865 | Compliant | | Enterprise Auth | SEP-990 | Compliant | | Client Metadata | SEP-991 | Compliant |

Full Compliance Report

Architecture

User Query
    │
    ▼
┌─────────────────┐
│  Planning Agent  │ ─── Decomposes into sub-queries
└────────┬────────┘
         │
    ┌────┴────┐
    ▼         ▼
┌───────┐ ┌───────┐
│Agent 1│ │Agent N│ ─── Parallel research (embedding-routed models)
└───┬───┘ └───┬───┘
    │         │
    ▼         ▼
┌─────────────────┐
│   Synthesizer   │ ─── Consensus + citations (Signal protocol)
└────────┬────────┘
         │
         ▼
┌─────────────────┐
│  Knowledge Base  │ ─── PGlite + pgvector (persistent)
└─────────────────┘

Core Abstractions

| Module | Purpose | |--------|---------| | Signal Protocol | Inter-agent communication with confidence scoring and consensus | | Rail Protocol | Bidirectional channels with backpressure, provenance, tunnels | | Error Taxonomy | Deterministic classification with auto-learning and circuit breakers | | Circuit Breaker | Model API fault tolerance with configurable thresholds and auto-recovery | | Parameter Normalization | Declarative alias system (q→query, cost→costPreference) | | RoleShift Protocol | Bidirectional server↔client via MCP sampling/elicitation | | Embedding Router | Local vector-based model selection via @terminals-tech/embeddings |

Circuit Breaker

Protects against cascading model API failures. Configurable via environment:

| Variable | Default | Description | |----------|---------|-------------| | RAILCIRCUITBREAKER | true | Enable circuit breaker | | RAILCIRCUITTHRESHOLD | 5 | Failures before tripping | | RAILCIRCUITRESET_MS | 120000 | Recovery timeout (ms) |

States: closed (normal) -> open (failing, requests rejected) -> half-open (testing recovery).

Transport (v2.0.0)

| Transport | Status | Use Case | |-----------|--------|----------| | Streamable HTTP | Primary | All new integrations | | SSE | Deprecated | Legacy compatibility only | | STDIO | Default | MCP clients (Claude, Jan AI, Continue) |

Links

• Homepage: terminals.tech
• npm: @terminals-tech/openrouter-agents
• GitHub: terminals-tech/openrouter-agents
• Docs: CLAUDE.md | Tool Patterns | Getting Started

Releasing

Releases are automated via release-please:

• Push conventional commits to main (e.g. feat:, fix:, chore:)
• release-please opens a version-bump PR
• Merge the PR → GitHub Release created automatically
• npm publish triggers on release via CI

npm test && npm publish --access public

Version: 2.0.0 | MCP SDK: 1.27.1 | MCP Spec: 2025-11-25 | Author: Tej Desai | License: MIT