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 DB_AUTO_HEAL=true for in-memory mode (no persistence, no message).

Full Changelog | Extensions Guide | MCP Compliance Report

Configuration

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

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

Full ENV Reference

<details>
<summary><strong>.mcp.json example (team-shareable)</strong></summary>

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

<details>
<summary><strong>Jan AI</strong></summary>

1. Enable MCP Servers in Settings → Advanced → Experimental
2. Click + to add server
3. Configure:
- Name: openrouter-agents
- Command: npx
- Arguments: @terminals-tech/openrouter-agents
- Environment: OPENROUTER_API_KEY=sk-or-...

Note: STDIO is now default - no --stdio flag needed.
</details>

<details>
<summary><strong>Claude Desktop</strong></summary>

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

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

<details>
<summary><strong>Continue / Zed / Other MCP Clients</strong></summary>

Standard MCP config - STDIO is default, no flags needed:

{

  "command": "npx",

  "args": ["@terminals-tech/openrouter-agents"],

  "env": { "OPENROUTER_API_KEY": "..." }

}

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

<details>
<summary><strong>Research</strong></summary>

| Tool | Description |
|------|-------------|
| research | Async research (returns job_id) |
| conduct_research | Sync research with streaming |
| batch_research | Parallel batch queries |
| research_follow_up | Context-aware follow-up |
| agent | Unified entrypoint (auto-routes) |
</details>

<details>
<summary><strong>Knowledge Base</strong></summary>

| Tool | Description |
|------|-------------|
| search | Hybrid BM25+vector search |
| retrieve | Index or SQL query |
| query | SQL SELECT with params |
| get_report | Get report by ID |
| history | List recent reports |
</details>

<details>
<summary><strong>Session & Graph</strong></summary>

| Tool | Description |
|------|-------------|
| undo / redo | Session time-travel |
| checkpoint | Named save points |
| fork_session | Create alternate timeline |
| graph_traverse | Explore knowledge graph |
| graph_clusters | Find node clusters |
| graph_pagerank | Importance rankings |
</details>

<details>
<summary><strong>Rail Protocol</strong></summary>

| Tool | Description |
|------|-------------|
| list_rails | List rails, tunnels, routes, consensus |
| explain_rail | Detailed rail/tunnel config |
| list_routes | All defined routes |
| list_tunnels | Active agent-to-agent tunnels |
| list_consensus | Streaming consensus sessions |
</details>

<details>
<summary><strong>Utility</strong></summary>

| Tool | Description |
|------|-------------|
| ping | Health check |
| get_server_status | Full diagnostics |
| job_status | Check async job |
| date_time | Current timestamp |
| calc | Math evaluation |
| list_tools | Available tools |
</details>

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 |
|----------|---------|-------------|
| RAIL_CIRCUIT_BREAKER | true | Enable circuit breaker |
| RAIL_CIRCUIT_THRESHOLD | 5 | Failures before tripping |
| RAIL_CIRCUIT_RESET_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:

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

Manual publish:

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