The MCP catalog

The catalog is the list of MCP servers Splox already knows how to talk to. You pick one, connect it once, and your agents can call its tools. It lives on the Tools screen, under Browse.

The Browse tab of the Splox Tools screen — The catalog: name, category, description, auth type and transport

What a catalog entry is

An entry is a server somebody else runs, plus everything Splox needs to reach it on your behalf. This is one, as the app fetches it:

curl -s "https://<your-host>/api/v1/mcp-catalog?page=1&per_page=8" \
  -H "Cookie: session=$SESSION"

{
  "mcp_servers": [
    {
      "id": "019b0a48-1145-7805-a4cb-7069736e6978",
      "name": "Reddit",
      "description": "Browse Reddit, search posts, read comments, vote, and manage subreddit subscriptions.",
      "url": "https://mcp.splox.io/reddit/mcp",
      "transport_type": "http",
      "auth_type": "oauth",
      "auth_config": {
        "oauth_scopes": "identity read submit vote mysubreddits subscribe history edit"
      },
      "image_url": "https://splox-app.s3.amazonaws.com/mcp-icons/reddit.png",
      "is_featured": true
    }
  ],
  "current_page": 1,
  "per_page": 8,
  "total_count": 83,
  "total_pages": 11
}

The two fields that decide what connecting feels like:

string

http or sse. How Splox speaks to the server. The catalog knows the right one; you only choose it when you add a server of your own.

string

oauth — you are redirected to the provider and come back with a token. manual — you paste API keys into named fields. Either way the credential is held by the platform, not by your harness. See Connections.

Some entries are Splox’s own bridges to a service (mcp.splox.io/reddit/mcp), some are the vendor’s own server (mcp.linear.app/sse, mcp.notion.com/sse). The distinction does not change anything about how you use it.

per_page is capped at 20 by the server, whatever you ask for. Page through with page=, or use the search box in the app.

Adding one

Click the card. You get a page that shows what the server is, the URL it lives at, and a form for the one thing Splox does not already know — who you are on the other side.

ABOUT
  Linear · Connect this MCP server via OAuth.
  sse  oauth  https://mcp.linear.app/sse

CONNECTION
  Connection name: Linear
  You will be redirected to Linear to authorize access. We never see your password.

  [Cancel]  [Connect]

ABOUT
  X (Twitter) · Connect this MCP server to your account.
  http  manual  https://mcp.splox.io/x/mcp

CREDENTIALS
  Connection name: X (Twitter)
  + How to get your credentials
  X-api-key *            X-api-secret *
  X-access-token *       X-access-token-secret *
  X-bearer-token *

  [Cancel]  [Connect]

Connecting Linear over OAuth — An OAuth entry asks for a name; the authorization happens at the provider

The Connection name is yours — it is how the server appears in your own list afterwards, and it matters when you connect the same provider twice for two different accounts.

Adding a server that is not in the catalog

Add MCP server takes a URL instead of an entry. You choose the transport yourself, and authentication is either none or custom headers.

The Add custom MCP server form — Any MCP endpoint, by URL, with headers you name

The app posts what you typed:

curl -s -X POST "https://<your-host>/api/v1/user-mcp-servers" \
  -H "Cookie: session=$SESSION" -H "Content-Type: application/json" \
  -d '{"name":"DeepWiki","url":"https://mcp.deepwiki.com/mcp",
       "transport_type":"http","auth_type":"manual","custom":true,
       "credentials":{},"auth_config":{"required_headers":[]}}'

{
  "server": {
    "id": "01a06134-991c-7fb2-a7ff-518d188c1608",
    "name": "DeepWiki",
    "url": "https://mcp.deepwiki.com/mcp",
    "transport_type": "http",
    "auth_type": "manual",
    "auth_config": {"required_headers": []},
    "is_system": false,
    "created_at": "2026-09-02T08:20:32.154318Z"
  },
  "status": "created"
}

That id is the point of the whole exercise. It is what an agent’s tools entry names.

What you have afterwards

The server shows up under Your MCP servers, with its transport, its auth type and a trash icon that removes it.

The Your MCP servers tab with one connected server — A connected server: this is where its uuid comes from

Ask the platform what it exposes:

curl -s "https://<your-host>/api/v1/user-mcp-servers/01a06134-991c-7fb2-a7ff-518d188c1608/tools" \
  -H "Cookie: session=$SESSION"

{
  "options": [
    {"label": "Ask Question",         "value": "ask_question"},
    {"label": "Read Wiki Contents",   "value": "read_wiki_contents"},
    {"label": "Read Wiki Structure",  "value": "read_wiki_structure"}
  ],
  "total": 3
}

Then give it to an agent, by uuid, in programs/<name>/main.py:

researcher = agent(
    "Researcher",
    system_prompt=prompt("researcher"),
    model="kimi-k3",
    provider="splox",
    tools=[
        "system:compute",
        "01a06134-991c-7fb2-a7ff-518d188c1608",                 # every tool it has
        # "01a06134-991c-7fb2-a7ff-518d188c1608#ask_question",  # or just this one
    ],
)

No file in the checkout lists your servers, so from inside a run the way to find the uuid and the slugs is to ask:

from tools.harness import harness_mcp_servers, harness_mcp_tools

for server in harness_mcp_servers():
    print(server["mcp_server_id"], server["name"])

print([t["name"] for t in harness_mcp_tools("system:search")["tools"]])

system:compute Compute
system:media Media
system:search Search
system:email Email
system:sms SMS
system:memory Memory
system:harness Harness
['fetch', 'search']

Get a slug wrong and git push origin main refuses the publish, naming the file and the slug — which is the cheapest place to find out. See Publishing a version.

The v2 API has the same two questions as GET /v2/tool-servers, with system:* ids for the platform packages and uuids for yours. Use that one from outside the product; the /api/v1 paths above are what the app itself calls.

​What a catalog entry is

​Adding one

​Adding a server that is not in the catalog

​What you have afterwards

What a catalog entry is

Adding one

Adding a server that is not in the catalog

What you have afterwards