MCP server for Harness platform access

Harness MCP Server 2.0

An MCP (Model Context Protocol) server that gives AI agents full access to the Harness.io platform through 11 consolidated tools and 245 resource types.

Why Use This MCP Server

Most MCP servers map one tool per API endpoint. For a platform as broad as Harness, that means 240+ tools — and LLMs get worse at tool selection as the count grows. Context windows fill up with schemas, and every new endpoint means new code.

This server is built differently:

• 11 tools, 245 resource types. A registry-based dispatch system routes harness_list, harness_get, harness_create, etc. to any Harness resource — pipelines, services, environments, orgs, projects, feature flags, cost data, and more. The LLM picks from 11 tools instead of hundreds.
• Full platform coverage. 41 default toolsets spanning CI/CD, GitOps, Feature Flags, Cloud Cost Management, Security Testing, Chaos Engineering, Database DevOps, Internal Developer Portal, Software Supply Chain, Infrastructure as Code Management, Release Management, Governance, Service Overrides, Knowledge Graph, and more. Opt-in Ansible coverage is available when you need inventory and playbook data.
• Multi-project workflows out of the box. Agents discover organizations and projects dynamically — no hardcoded env vars needed. Ask "show failed executions across all projects" and the agent can navigate the full account hierarchy.
• 35 prompt templates. Pre-built prompts for common workflows: build & deploy apps end-to-end, debug failed pipelines, review DORA metrics, triage vulnerabilities, optimize cloud costs, audit access control, plan feature flag rollouts, review pull requests, approve pending pipelines, and more.
• Works everywhere. Stdio transport for local clients (Claude Desktop, Cursor, Devin Desktop), HTTP transport for remote/shared deployments, Docker and Kubernetes ready.
• Zero-config start. Just provide a Harness API key. Account ID is auto-extracted from PAT and SAT tokens, org/project defaults are optional, and toolset filtering lets you expose only what you need.
• Extensible by design. Adding a new Harness resource means adding a declarative data file — no new tool registration, no schema changes, no prompt updates.

Prerequisites

Before installing or running the server, you need a Harness API key:

1. Log in to your Harness account
2. Go to My Profile → API Keys → + New API Key
3. Create a new Token under the API key — this generates a PAT or SAT in the format <prefix>.<accountId>.<tokenId>.<secret>
4. Save the token somewhere secure — you'll need it in the next step

For detailed instructions, see the Harness API Quickstart.

Quick Start

Option 0: Hosted Harness MCP

If your Harness account has the hosted MCP service enabled, clients that support remote MCP servers can connect directly to the managed endpoint instead of running the server locally.

Important: The hosted MCP service uses Harness Platform OAuth, not HARNESS_API_KEY. It must also be enabled/configured per account by Harness Support before the endpoint can be used.

See Hosted Harness MCP for configuration examples.

Option 1: npx (Recommended)

No install required — just run it:

HARNESS_API_KEY=pat.xxx.xxx.xxx npx harness-mcp-v2@latest

Or configure the API key in your AI client (see Client Configuration below).

# Stdio transport (default — for Claude Desktop, Cursor, Devin Desktop, etc.)
HARNESS_API_KEY=pat.xxx npx harness-mcp-v2

# HTTP transport (for remote/shared deployments)
HARNESS_API_KEY=pat.xxx npx harness-mcp-v2 http --port 8080

Note: The account ID is auto-extracted from PAT and SAT tokens (pat.<accountId>... or sat.<accountId>...), so HARNESS_ACCOUNT_ID is only needed for API keys without an embedded account segment.

Option 2: Global Install

npm install -g harness-mcp-v2

# Then run directly
harness-mcp-v2

Option 3: Build from Source

For development or customization:

git clone https://github.com/harness/mcp-server.git
cd mcp-server
pnpm install
pnpm build

# Run
pnpm start              # Stdio transport
pnpm start:http         # HTTP transport
pnpm inspect            # Test with MCP Inspector

Anthropic MCP Directory bundle

The MCPB bundle manifest lives in [mcp-directory/](mcp-directory/), and the 512×512 bundle icon is tracked at [icon.png](icon.png) in the repository root. The packaged archive contains root-level manifest.json, icon.png, server/, package.json, npm-shrinkwrap.json, and production node_modules/.

To keep the archive small, build MCPB packages from a staging directory:

pnpm prepare:mcpb

The staging directory is written to dist/mcpb/ with production dependencies installed from npm-shrinkwrap.json using npm's flat layout. The pinned official MCPB CLI validates it and creates dist/harness-mcp-server-<version>.mcpb.

Version tags matching v*.*.* publish that bundle to the corresponding GitHub Release automatically. To backfill an existing release without republishing npm, run the Release workflow manually with its release_tag input (for example, v3.2.20). The workflow checks out and builds that exact tag before replacing only its versioned MCPB asset.

CLI Usage

harness-mcp-v2 [stdio|http] [--port <number>]

Options:
  --port <number>  Port for HTTP transport (default: 3000, or PORT env var)
  --help           Show help message and exit
  --version        Print version and exit

Transport defaults to stdio if not specified. Use http for remote/shared deployments.

HTTP Transport

When running in HTTP mode, the server exposes:

Endpoint	Method	Description
/mcp	POST	MCP JSON-RPC endpoint (initialize + session requests)
/mcp	GET	SSE stream for server-initiated messages (progress, elicitation)
/mcp	DELETE	Terminate an active MCP session
/mcp	OPTIONS	CORS preflight
/health	GET	Health check — returns { "status": "ok", "sessions": <count> }
/.well-known/oauth-protected-resource	GET	RFC 9728 metadata when HARNESS_MCP_MODE=oauth
/.well-known/oauth-protected-resource/mcp	GET	Path-aware RFC 9728 metadata for the default /mcp resource

The HTTP transport runs in session-based mode. A new MCP session is created on initialize, the server returns an mcp-session-id header, and subsequent requests for that session must include the same header.

Operational constraints in HTTP mode:

• Set HARNESS_MCP_AUTH_TOKEN for shared or remotely reachable single-user and multi-user deployments. When set, every POST, GET, and DELETE request to /mcp must include Authorization: Bearer <token>.
• OAuth mode accepts HarnessID access tokens instead of HARNESS_MCP_AUTH_TOKEN and can bind to a non-loopback address without the unauthenticated opt-out.
• Non-loopback single-user and multi-user binds require HARNESS_MCP_AUTH_TOKEN by default. To run unauthenticated on a non-loopback interface anyway, set HARNESS_MCP_ALLOW_UNAUTHENTICATED_HTTP=true explicitly.
• POST /mcp without mcp-session-id must be an initialize request.
• POST /mcp, GET /mcp, and DELETE /mcp for existing sessions require the mcp-session-id header.
• GET /mcp is used for SSE notifications (progress updates and elicitation prompts).
• Idle sessions are reaped after MCP_SESSION_TTL_MS milliseconds once no request or SSE stream is active (default 1800000, or 30 minutes).
• GET /health is the only non-MCP endpoint.
• Request body size is capped by HARNESS_MAX_BODY_SIZE_MB (default 10 MB).
• Set x-harness-pipeline-version: 0 or 1 on the initialize request to select V0 or V1 pipeline resources for that HTTP session.
• Set x-harness-auto-approve-risk: none|low_write|medium_write|high_write|all on the initialize request to choose a stricter per-session auto-approval threshold. The server caps this value at the deployment-level HARNESS_AUTO_APPROVE_RISK, so a session can reduce but not expand the configured approval ceiling.

HarnessID OAuth Mode

Set HARNESS_MCP_MODE=oauth to let remote MCP clients discover HarnessID and complete OAuth 2.1 Authorization Code with PKCE. OAuth mode is available only with HTTP transport. Production HarnessID, MCP resource, and API routing defaults are built in:

HARNESS_MCP_MODE=oauth

This defaults to the issuer https://id.harness.io/idp/realms/HarnessIDP, resource https://mcp.harness.io/mcp, OAuth client mcp-client, and Harness API base https://mcp.harness.io/cli. Override them only for QA, local development, or another Harness environment.

HARNESS_API_KEY must not be set in this mode. HARNESS_MCP_OAUTH_JWKS_URI defaults to <issuer>/protocol/openid-connect/certs, and HARNESS_ACCOUNT_ID is unnecessary because the account comes from the token.

The server publishes RFC 9728 protected-resource metadata and returns this challenge when a client has not authenticated:

HTTP/1.1 401 Unauthorized
WWW-Authenticate: Bearer resource_metadata="https://mcp.harness.io/.well-known/oauth-protected-resource/mcp"

It validates the HarnessID access token's RS256 signature, iss, expiry, and sub using the configured JWKS endpoint, and checks that the token was issued to HARNESS_MCP_OAUTH_CLIENT_ID through the azp claim. HARNESS_MCP_OAUTH_RESOURCE is the RFC 9728 protected-resource identifier used for discovery and challenges. Current HarnessID access tokens use aud: account rather than the MCP URL, so the resource is not compared with aud.

The account ID comes from the token's HARNESS_MCP_OAUTH_ACCOUNT_CLAIM claim (account_id by default), which the HarnessID organization scope populates. Each session stores the caller's access token and forwards it to the Harness API as Authorization: Bearer, so Harness RBAC and audit records reflect the logged-in user rather than a shared PAT. The session is bound to the sub and account it was created with: a later request may carry a refreshed token, but one for a different user or account is rejected.

Clients normally need only the MCP resource URL:

{
  "mcpServers": {
    "harness": {
      "url": "https://mcp.harness.io/mcp"
    }
  }
}

The client reads the protected-resource metadata, discovers HARNESS_MCP_OAUTH_ISSUER, and then uses that authorization server's RFC 8414 metadata. If the client does not support dynamic client registration, use the pre-registered mcp-client client ID.

See HarnessID OAuth for a self-hosted MCP server for the QA Keycloak checklist and validation commands.

Multi-User Mode

Set HARNESS_MCP_MODE=multi-user for shared HTTP deployments where each client authenticates as a different Harness user. In this mode:

• HARNESS_API_KEY must not be set in the server config — the server holds no Harness credentials.
• Each session must provide x-harness-api-key on the initialize request. x-harness-account-id is required only when the API key does not embed an account segment.
• Sessions may also provide x-harness-org and x-harness-project headers to set default scope for that session.
• The Harness API key flows through to every Harness API call for that session, so the audit trail in Harness reflects the real user.
• HARNESS_MCP_AUTH_TOKEN is independent and can still be used as an additional transport-layer gate.

# Health check
curl http://localhost:3000/health

# MCP initialize request (capture mcp-session-id response header)
# In multi-user mode, x-harness-api-key is required on initialize.
# x-harness-account-id is needed only for API keys without an embedded account segment.
curl -i -X POST http://localhost:3000/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "Authorization: Bearer $HARNESS_MCP_AUTH_TOKEN" \
  -H "x-harness-api-key: $HARNESS_API_KEY" \
  -H "x-harness-account-id: $HARNESS_ACCOUNT_ID" \
  -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-03-26","capabilities":{},"clientInfo":{"name":"test","version":"1.0"}}}'

# Subsequent MCP request (use returned session ID)
curl -X POST http://localhost:3000/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "Authorization: Bearer $HARNESS_MCP_AUTH_TOKEN" \
  -H "mcp-session-id: <session-id>" \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/list","params":{}}'

# Terminate session
curl -X DELETE http://localhost:3000/mcp \
  -H "Authorization: Bearer $HARNESS_MCP_AUTH_TOKEN" \
  -H "mcp-session-id: <session-id>"

HARNESS_MCP_ALLOWED_HOSTS controls Host-header validation for DNS-rebinding protection, and CORS limits browser origins. Neither is authentication; use HARNESS_MCP_AUTH_TOKEN or an authenticated gateway/reverse proxy for access control.

Client Configuration

Note: HARNESS_ORG and HARNESS_PROJECT are optional. They set the org ID and project ID used when not specified per tool call. Agents can discover orgs and projects dynamically using harness_list(resource_type="organization") and harness_list(resource_type="project"). The deprecated names HARNESS_DEFAULT_ORG_ID and HARNESS_DEFAULT_PROJECT_ID are still accepted for backward compatibility.

Hosted Harness MCP

Harness also supports a hosted MCP endpoint for accounts that have the managed service enabled. This is useful when you want a shared remote MCP endpoint instead of running npx harness-mcp-v2 or self-hosting the HTTP transport yourself.

Important: Hosted MCP authentication uses Harness Platform OAuth. It does not use HARNESS_API_KEY in the client config. Hosted MCP availability is configured per Harness account, so you will need to work with Harness Support to enable/configure the setting before using it.

The hosted endpoint https://mcp.harness.io/mcp is a managed service. Client-side MCP config in Claude, Cursor, or Cowork cannot override which Harness environment it routes to. For Harness0 or another private Harness SaaS environment, ask Harness Support to enable/configure hosted MCP for that environment, or run the local/self-hosted server and set HARNESS_BASE_URL to the target Harness host.

Hosted MCP example:

{
  "mcpServers": {
    "harness-prod1-mcp": {
      "url": "https://mcp.harness.io/mcp",
      "auth": {
        "CLIENT_ID": "mcp-client"
      }
    }
  }
}

Example with both hosted and local entries:

{
  "mcpServers": {
    "harness-hosted": {
      "url": "https://mcp.harness.io/mcp",
      "auth": {
        "CLIENT_ID": "mcp-client"
      }
    },
    "harness-local": {
      "command": "/absolute/path/to/npx",
      "args": ["-y", "harness-mcp-v2@latest"],
      "env": {
        "HARNESS_API_KEY": "pat.xxx.xxx.xxx",
        "PATH": "/directory/containing/node:/usr/local/bin:/usr/bin:/bin"
      }
    }
  }
}

Troubleshooting npx ENOENT or node: No such file or directory

This is a client process-launch failure, not a Harness authentication failure. The MCP server has not started yet, so changing HARNESS_API_KEY will not affect spawn npx ENOENT.

GUI apps (Cursor, Claude Desktop, Devin Desktop, VS Code) don't always inherit your shell's PATH, so they can fail to find npx or node after a config reload. Fix this by using absolute paths and explicitly setting PATH in the env block:

{
  "mcpServers": {
    "harness": {
      "command": "/absolute/path/to/npx",
      "args": ["-y", "harness-mcp-v2"],
      "env": {
        "HARNESS_API_KEY": "pat.xxx.xxx.xxx",
        "PATH": "/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin"
      }
    }
  }
}

Find your paths with which npx and which node in a terminal, then make sure the directory containing node is included in the PATH value above. Common locations:

• Homebrew (macOS): /opt/homebrew/bin/npx
• nvm: ~/.nvm/versions/node/v20.x.x/bin/npx (run nvm which current to find the exact path)
• System Node: /usr/local/bin/npx

Claude Desktop (claude_desktop_config.json)

npx (zero install)

{
  "mcpServers": {
    "harness": {
      "command": "/absolute/path/to/npx",
      "args": ["-y", "harness-mcp-v2@latest"],
      "env": {
        "HARNESS_API_KEY": "pat.xxx.xxx.xxx",
        "PATH": "/directory/containing/node:/usr/local/bin:/usr/bin:/bin"
      }
    }
  }
}

node (local install)

npm install -g harness-mcp-v2

{
  "mcpServers": {
    "harness": {
      "command": "/absolute/path/to/harness-mcp-v2",
      "env": {
        "HARNESS_API_KEY": "pat.xxx.xxx.xxx",
        "PATH": "/directory/containing/node:/usr/local/bin:/usr/bin:/bin"
      }
    }
  }
}

Claude Code (via claude mcp add)

npx (zero install)

claude mcp add harness -- npx harness-mcp-v2

node (local install)

npm install -g harness-mcp-v2
claude mcp add harness -- harness-mcp-v2

Then set HARNESS_API_KEY in your environment or .env file.

Cursor (.cursor/mcp.json)

npx (zero install, recommended for local Cursor configs)

{
  "mcpServers": {
    "harness": {
      "command": "/absolute/path/to/npx",
      "args": ["-y", "harness-mcp-v2@latest"],
      "env": {
        "HARNESS_API_KEY": "pat.xxx.xxx.xxx",
        "PATH": "/directory/containing/node:/usr/local/bin:/usr/bin:/bin"
      }
    }
  }
}

Run which npx in a terminal and use that full path for command; include the directory from which node at the front of PATH.

node (local install)

npm install -g harness-mcp-v2

{
  "mcpServers": {
    "harness": {
      "command": "/absolute/path/to/harness-mcp-v2",
      "env": {
        "HARNESS_API_KEY": "pat.xxx.xxx.xxx",
        "PATH": "/directory/containing/node:/usr/local/bin:/usr/bin:/bin"
      }
    }
  }
}

Run which harness-mcp-v2 after npm install -g harness-mcp-v2 and use that full path for command; include the directory from which node at the front of PATH.

Devin Desktop (~/.windsurf/mcp.json)

npx (zero install)

{
  "mcpServers": {
    "harness": {
      "command": "/absolute/path/to/npx",
      "args": ["-y", "harness-mcp-v2@latest"],
      "env": {
        "HARNESS_API_KEY": "pat.xxx.xxx.xxx",
        "PATH": "/directory/containing/node:/usr/local/bin:/usr/bin:/bin"
      }
    }
  }
}

node (local install)

npm install -g harness-mcp-v2

{
  "mcpServers": {
    "harness": {
      "command": "/absolute/path/to/harness-mcp-v2",
      "env": {
        "HARNESS_API_KEY": "pat.xxx.xxx.xxx",
        "PATH": "/directory/containing/node:/usr/local/bin:/usr/bin:/bin"
      }
    }
  }
}

Using a local build from source?

Replace the command with the path to your built index.js:

{
  "command": "node",
  "args": ["/absolute/path/to/harness-mcp-v2/build/index.js", "stdio"]
}

MCP Gateway

The Harness MCP server is fully compatible with MCP Gateways — reverse proxies that provide centralized authentication, governance, tool routing, and observability across multiple MCP servers. Since the server implements the standard MCP protocol with both stdio and HTTP transports, it works behind any MCP-compliant gateway with no code changes.

Why use a gateway?

• Centralized credential management — no API keys in agent configs
• Governance & audit logging for all tool calls across teams
• Single endpoint for agents instead of N connections to N MCP servers
• Access control — restrict which teams can use which tools

Docker MCP Gateway

Register the server in your Docker MCP Gateway configuration:

{
  "mcpServers": {
    "harness": {
      "command": "npx",
      "args": ["harness-mcp-v2"],
      "env": {
        "HARNESS_API_KEY": "pat.xxx.xxx.xxx"
      }
    }
  }
}

Portkey

Add the Harness MCP server to your Portkey MCP Gateway for enterprise governance, cost tracking, and multi-LLM routing:

{
  "mcpServers": {
    "harness": {
      "command": "npx",
      "args": ["harness-mcp-v2"],
      "env": {
        "HARNESS_API_KEY": "pat.xxx.xxx.xxx"
      }
    }
  }
}

LiteLLM

Add to your LiteLLM proxy config:

mcp_servers:
  - name: harness
    command: npx
    args:
      - harness-mcp-v2
    env:
      HARNESS_API_KEY: "pat.xxx.xxx.xxx"

Envoy AI Gateway

The server works with Envoy AI Gateway's MCP support via HTTP transport:

# Start the server in HTTP mode
HARNESS_API_KEY=pat.xxx.xxx.xxx npx harness-mcp-v2 http --port 8080

Then configure Envoy to route to http://localhost:8080/mcp as an upstream MCP backend.

Kong

Use Kong's AI MCP Proxy plugin to expose the Harness MCP server through your existing Kong gateway infrastructure.

Other Gateways

Any gateway that supports the MCP specification (Microsoft MCP Gateway, IBM ContextForge, Cloudflare Workers, etc.) can proxy this server. For stdio-based gateways, use the default transport. For HTTP-based gateways, start the server with http transport and point the gateway at the /mcp endpoint.

Docker

Build and run the server as a Docker container:

# Build the image
pnpm docker:build

# Run with your .env file
pnpm docker:run

# Or run directly with env vars
docker run --rm -p 3000:3000 \
  -e HARNESS_API_KEY=pat.xxx.xxx.xxx \
  -e HARNESS_ACCOUNT_ID=your-account-id \
  harness-mcp-server

The container runs in HTTP mode on port 3000 by default with a built-in health check.

Kubernetes

Deploy to a Kubernetes cluster using the provided manifests:

# 1. Edit the Secret with your real credentials
#    k8s/secret.yaml — replace HARNESS_API_KEY and HARNESS_ACCOUNT_ID

# 2. Apply all manifests
kubectl apply -f k8s/

# 3. Verify the deployment
kubectl -n harness-mcp get pods

# 4. Port-forward for local testing
kubectl -n harness-mcp port-forward svc/harness-mcp-server 3000:80
curl http://localhost:3000/health

The deployment runs 2 replicas with readiness/liveness probes, resource limits, and non-root security context. The Service exposes port 80 internally (targeting container port 3000).

Configuration

The server automatically loads environment variables from a .env file in the project root if one exists. Copy .env.example to .env and fill in your values. Environment variables can also be set via your shell or MCP client config.

Variable	Required	Default	Description