Zelkor

Register Extra MCP Backends ​

Zelkor ships infrastructure MCP servers (Postgres, Qdrant, sandbox, AI Gateway /v1). Customer SaaS or internal tools run as your ClusterIP Deployment; you register them on the unified MCP gateway. Agents keep a single MCP_URL — they do not call your MCP Service directly.

Bring the agent you already wrote: tool secrets stay on the MCP pod or gateway, not in the agent. With NetworkPolicies enabled, agent egress to tools goes only through the MCP gateway.

Prerequisites ​

  • Platform release running with workspace.tools.enabled: true.
  • GitOps access to upgrade the platform Helm release (not the agent release).
  • Either a ClusterIP MCP Service in the cluster, or a hosted MCP hostname you want Envoy to dial.

Deploy your MCP server ​

For an in-cluster server: run your vendor or custom MCP image as a normal Kubernetes workload. Store SaaS credentials in a Secret on that Deployment. Example Service name acme-itsm-mcp on port 8080.

Zelkor does not ship ServiceNow, Jira, Salesforce, or Tavily MCP images.

For a hosted MCP (Tavily, a partner URL): skip a wrapper Deployment. Create a Secret whose data key is apiKey (the gateway reads that key name), then register the FQDN below.

bash
kubectl create secret generic tavily-mcp-key \
  --namespace zelkor \
  --from-literal=apiKey='tvly-YOUR_KEY'

Do not put the key in the hostname URL. The agent never receives this Secret.

Register on the platform release ​

Add an entry to workspace.tools.extraBackends on the zelkor-platform release. Chart default is an empty list.

yaml
workspace:
  tools:
    extraBackends:
      - name: acme
        service:
          name: acme-itsm-mcp
          port: 8080
        path: /mcp
        apiKey:
          secretRef:
            name: acme-mcp-gateway-key
        forwardHeaders:
          - name: X-Tenant-ID

Apply with your overlay file:

bash
helm upgrade zelkor-platform charts/zelkor-platform \
  --namespace zelkor \
  --reuse-values \
  -f my-platform-overlay.yaml

External hostname (no wrapper Deployment; Envoy dials this FQDN). Public HTTPS uses the cluster’s system CAs unless you set tls.caSecretRef.

yaml
      - name: tavily
        fqdn:
          hostname: mcp.tavily.com
          port: 443
        path: /mcp
        apiKey:
          secretRef:
            name: tavily-mcp-key

tools/list then includes tavily__tavily_search (and the vendor’s other tools) next to postgres__query. The worker calls MCP_URL with a Zelkor JWT; Envoy adds Authorization: Bearer from tavily-mcp-key.

Naming rules ​

RuleDetail
nameDNS-label safe; used as the tool prefix
ReservedDo not use postgres, qdrant, sandbox, egress, nemo, aegra, or langfuse
__Must not appear in name
TargetSet exactly one of service or fqdn

Gateway tools/list returns {name}__{tool} (for example acme__create_incident). tools/call strips the prefix and forwards JSON-RPC to your backend.

Optional fields: toolSelector, forwardHeaders (not Authorization — use apiKey instead), tls.caSecretRef (private CA). Without caSecretRef, an FQDN extra uses system CAs (same as LLM provider backends). egress.cidrs / ports are optional GitOps notes for your own CNI; Community Edition does not apply them to Envoy. Isolation is the agent NetworkPolicy plus the registered FQDN on MCPRoute. See External and Third-Party MCP.

Match agent tools.json before deploy ​

If your project lists MCP servers in tools.json, zelkor deploy compares names with workspace.tools.extraBackends on the platform release. On mismatch it exits non-zero and prints a GitOps snippet — it does not patch the platform chart for you.

Register extras on the platform first, then deploy the agent:

bash
helm upgrade zelkor-platform ... -f overlay-with-extraBackends.yaml
cd my-agent && zelkor deploy --env staging

Mode A vs Mode B ​

ModeWhat you do
AAgent reads MCP_URL and calls tools/list / tools/call itself
BEnable MCP inject on the agent chart so the runtime binds listed tools at graph load

Both modes see native and extra tools on the same gateway. Details: Drop-In Agent Contract.

Verify ​

From a pod that may reach the MCP gateway (or via port-forward to the gateway Service):

bash
curl -sS "http://zelkor-platform-mcp:80/mcp" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}'

Expect tool names including your prefix alongside postgres__query, sandbox__execute_python, etc.

Identity and isolation ​

Zelkor forwards tenant headers you configure. It does not enforce row-level security inside a community SaaS MCP — your server must honor tenant context or you run one MCP per tenant. Native Postgres and Qdrant wrappers are the servers Zelkor guarantees to filter.

See also ​