Design PCBs from Gemini CLI and Gemini agents

Gemini CLI with sign-in

Add the server for your user, so it is there in every project:

gemini mcp add --transport http --scope user pcbeditor https://api.robodib.com/mcp

Or write the entry yourself. Use httpUrl, which is Gemini CLI’s key for Streamable HTTP:

{
  "mcpServers": {
    "pcbeditor": {
      "httpUrl": "https://api.robodib.com/mcp"
    }
  }
}

Start Gemini CLI and run /mcp auth pcbeditor. Gemini CLI discovers PCBEditor’s OAuth endpoints, registers itself and opens the consent page in your browser. Run /mcp to see the tools.

Gemini CLI with a personal access token

Create a token at pcbeditor.com/profile/ai-tools and keep it in an environment variable. Gemini CLI expands environment variables in settings.json string values, so the file holds only the variable name:

{
  "mcpServers": {
    "pcbeditor": {
      "httpUrl": "https://api.robodib.com/mcp",
      "headers": {
        "Authorization": "Bearer $PCBEDITOR_TOKEN"
      }
    }
  }
}

export PCBEDITOR_TOKEN="pcbe_..."
gemini

The CLI form works too, but your shell expands the variable when you run it, so the token value is written into settings.json:

gemini mcp add --transport http --scope user \
  --header "Authorization: Bearer $PCBEDITOR_TOKEN" pcbeditor https://api.robodib.com/mcp

Gemini agents with Google ADK

Connect to the MCP server

The Agent Development Kit’s McpToolset speaks Streamable HTTP. Pass the server URL and your token as a header:

import os
from google.adk.agents import LlmAgent
from google.adk.tools.mcp_tool import McpToolset
from google.adk.tools.mcp_tool.mcp_session_manager import StreamableHTTPConnectionParams

pcbeditor = McpToolset(
    connection_params=StreamableHTTPConnectionParams(
        url="https://api.robodib.com/mcp",
        headers={"Authorization": "Bearer " + os.environ["PCBEDITOR_TOKEN"]},
    )
)

root_agent = LlmAgent(
    name="pcb_designer",
    model="gemini-flash-latest",
    instruction="Design and check PCBs with the PCBEditor tools. Follow design jobs with get_job.",
    tools=[pcbeditor],
)

Or load the OpenAPI spec

ADK’s OpenAPIToolset turns every operation in the spec into a tool. The spec is at https://api.robodib.com/agent-api/openapi.json.

import os, urllib.request
from google.adk.tools.openapi_tool.auth.auth_helpers import token_to_scheme_credential
from google.adk.tools.openapi_tool.openapi_spec_parser.openapi_toolset import OpenAPIToolset

spec = urllib.request.urlopen("https://api.robodib.com/agent-api/openapi.json").read().decode()
auth_scheme, auth_credential = token_to_scheme_credential(
    "apikey", "header", "Authorization", "Bearer " + os.environ["PCBEDITOR_TOKEN"]
)
pcbeditor = OpenAPIToolset(
    spec_str=spec, spec_str_type="json",
    auth_scheme=auth_scheme, auth_credential=auth_credential,
)

Plain Gemini function calling

Without ADK, declare the tools you need as Gemini functions. Function declarations use a subset of the OpenAPI schema, so each operation’s request schema in the spec maps across. When the model returns a function call, your code sends it to PCBEditor as a REST request:

POST https://api.robodib.com/agent-api/v1/tools/{name}
Authorization: Bearer pcbe_...
Content-Type: application/json

The body and response for every tool are defined in the spec. Return the response to the model as the function result.

Common questions

Can Gemini design a PCB?

With PCBEditor's MCP server connected, Gemini CLI or a Gemini agent can ask PCBEditor for a complete board: parts, schematic, placement, autorouting and a design-rule check. Gemini runs the conversation; PCBEditor's engines do the wiring, routing and checks.

Should I use httpUrl or url in settings.json?

httpUrl. Gemini CLI uses httpUrl for Streamable HTTP servers, which is what PCBEditor's server speaks; url is for the older SSE transport.

Why does /mcp auth fail over SSH?

Gemini CLI's OAuth sign-in needs a local browser and a redirect to localhost. On a remote machine without one, use a personal access token in the headers instead.

Does the Gemini API read OpenAPI specs?

Gemini function declarations use a subset of the OpenAPI schema, and your code executes the calls. Google's Agent Development Kit can load PCBEditor's MCP server or its OpenAPI spec directly and turn each tool into a function the model can call.