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Public API and MCP Servers

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ZennoPoster and ProjectMaker 7.9.2 introduced a public HTTP API (PublicApi) and a suite of public MCP servers. You can control the product externally from your own scripts and applications or through an AI assistant, with access permissions defined by your API key.

Requirements

ZennoPoster 7.9.2 or newer; ZennoDroid 2.6.1 or newer for Android workflows. Windows x64. ProjectMaker must be running with the required project open.

1. What’s New in 7.9.2​

Public REST API (PublicApi) — more than 100 operations under a unified contract:

  • working with a project in ProjectMaker: action tree, variables, lists, tables, and static data;
  • managing tasks and execution sessions in ZennoPoster;
  • controlling a browser instance: navigation, clicks, text input, and screenshots.

The contract is described in OpenAPI, and you can generate a client for any language from the specification.

API keys with flexible permissions. Keys are issued in ProjectMaker. Each key has its own set of permissions (scopes) and maximum operation tier, ranging from strictly read-only access to full control.

Public MCP servers built on top of this API: download them, enter your key, and connect them to your AI client. The assistant’s permissions are determined by your key, and connections are accepted only from the local machine.

The product’s built-in AI chat runs on the same infrastructure: the same API and the same permission model, with no hidden privileged channels. To learn more about the chat itself, see AI Assistant.

2. Two Sets of MCP Servers​

This is the most important thing to understand before setup. There are two sets of servers, and they serve different purposes.

Internal serversPublic servers
Ports6107 ProjectMCP, 6108 BrowserMCP6207-6211
StartupAutomatically with ProjectMakerManually, downloaded separately
API keyNot requiredRequired, with permissions defined by you
CoverageProjectMaker project and browserProject, browser, ZennoPoster tasks, ZennoDroid
SetupSetup Guide for AI AssistantsThis page

The internal servers support the built-in AI chat. You can also connect an external assistant to them if you only need to work with the ProjectMaker project and browser without granular access control.

The public servers are needed when you want to manage ZennoPoster tasks, work with ZennoDroid, or control exactly what the assistant is allowed to do.

Do Not Use Ports 6107-6113

The product’s internal infrastructure uses this port range. Do not run your own processes on these ports, or the built-in AI chat will stop working.

3. API Keys: Permissions and Tiers​

Keys are issued in ProjectMaker under Settings → API Keys → Add. In the dialog, specify:

  • Label — a name that will help you identify who the key was issued to.
  • Maximum tier — the highest operation severity level allowed. T0 permits read-only access, while higher tiers enable changes.
  • Permissions (scopes) — a set of access areas. By default, only read permissions are enabled.
The Key Is Shown Only Once

Copy and save the key as soon as you create it. You cannot view it again; if you lose it, the easiest solution is to delete it and issue a new one.

If a key does not have sufficient permissions, the API returns a structured error specifying the exact permission or tier that is missing.

Recommended workflow:

  1. Issue a key with the T0 tier and read-only permissions.
  2. Make sure the assistant can see the project and answer questions about it.
  3. Issue a second key with write permissions and use it when changes are needed.

Using a separate key for each client and machine makes revocation easier: if something goes wrong, you will know exactly which key to delete.

4. Installing Public Servers​

Step 1. Choose the Servers You Need​

TaskServerPort
Read and edit the project: blocks, connections, variables, lists, tablesMCP.ProjectMaker6207
Control the browser open in ProjectMakerMCP.Instance6208
Control the browser within ZennoPoster tasksMCP.Instance, second copy6209
Create and manage tasks: start, threads, stop, logsMCP.ZennoPoster6210
Work with Android devices through ZennoDroidMCP.Android6211

You do not need to install everything at once. If you are starting with a single server, choose MCP.ProjectMaker.

Step 2. Download and Extract​

The archives are available on the releases page and follow a naming pattern such as MCP.ProjectMaker-v0.2.0-win-x64.zip. Extract the archive to a convenient folder, such as C:\ZennoMCP\. These are ready-to-use, self-contained builds, so you do not need to install .NET separately.

Step 3. Start the Server with Your Key​

Open the folder containing the extracted server, type powershell in the File Explorer address bar, and press Enter. Replace zp_xxx with your key.

ProjectMaker, port 6207
.\ZennoLab.AI.MCP.ProjectMaker.exe --NeuroBot:ApiKey=zp_xxx
Browser in ProjectMaker, port 6208
.\ZennoLab.AI.MCP.Instance.exe --Instance:ApiKey=zp_xxx
ZennoPoster tasks, port 6210
.\ZennoLab.AI.MCP.ZennoPoster.exe --ZennoPosterApi:ApiKey=zp_xxx
Android, port 6211
.\ZennoLab.AI.MCP.Android.exe --Android:ApiKey=zp_xxx

The console window must remain open: if the server stops running, the assistant loses access.

Starting Without Entering the Key

Enter the key in the ApiKey field in the appsettings.json file next to the program, and you will be able to start the server by double-clicking the exe. You can also pass the key through an environment variable such as NeuroBot__ApiKey. The command-line argument takes precedence over the environment variable and the settings file.

Browser Within ZennoPoster Tasks, Port 6209​

This is a second copy of the Instance server with different parameters. Extract the archive into a second folder and start it as follows:

.\ZennoLab.AI.MCP.Instance.exe --urls http://localhost:6209 `
  --Instance:Target=zennoposter --Instance:BaseUrl=http://localhost:5300/api/v1 `
  --Instance:ApiKey=zp_xxx

5. Connecting an AI Client​

Ready-made installation buttons for Cursor and VS Code, along with commands for Claude Code, are available on the installation page. The same steps are shown manually below.

Claude Code​

claude mcp add --transport http projectmaker http://localhost:6207
claude mcp list

GitHub Copilot, Cursor, VS Code​

Add the following to the .mcp.json file in your profile folder (Win + R → %USERPROFILE%):

{
  "servers": {
    "projectmaker": { "type": "http", "url": "http://localhost:6207" },
    "zennoposter": { "type": "http", "url": "http://localhost:6210" }
  }
}

Restart the client after editing the file: the configuration is loaded at startup.

LM Studio, Local Model​

You need LM Studio 0.3.17 or newer; earlier versions do not support MCP. Choose a model that supports tool use, otherwise it will not be able to execute commands. Add the block to the mcp.json file using the editor inside the program; the relevant section has a different name there:

{
  "mcpServers": {
    "projectmaker": { "url": "http://localhost:6207" }
  }
}
note

Local models are less capable than cloud-based ones: they are more likely to get lost in large projects and sometimes call the wrong tools. They are sufficient for reading and explaining a project, but a cloud model is better for complex changes.

Testing the Connection​

Ask the assistant:

Which ZennoPoster tools are available to you? List them.

If it lists the available tools, everything is working.

6. What an External Assistant Can Do​

Read the Project as a Graph​

  • get_project_structure returns nodes (type, label, starting point, switch, disabled state, whether they belong to an error branch, groupId, and actionId) and edges (OnSuccess, OnError, Default, Case-N, including implicit transitions). The response has three levels: a group overview, a single-group snapshot, or the complete graph, preventing excessive output for large templates.
  • find_path(from, to) finds the shortest path between two blocks.
  • get_action_connections(actionId) shows all incoming and outgoing connections for a specific block.

This allows the assistant to answer questions such as “how does execution reach this block?” and “what will break if this branch is removed?”

Saving and Verifying File State​

  • save_project and open_project return fileHash (the SHA-256 hash of the .zp file contents, calculated after writing), fileSizeBytes, and lastWriteTimeUtc. Opening the same file again produces an identical hash, allowing you to verify that the file on disk is exactly what you expected.
  • get_project_info includes the hasUnsavedChanges flag; the hash is calculated only when there are no unsaved changes.
  • By default, close_project will not close a project with unsaved changes. It returns 409 failed_precondition to prevent your work from being silently lost. To close it and discard the changes, you must explicitly pass discardUnsavedChanges: true.

Tasks, Browser, and Data​

  • ZennoPoster tasks and sessions: starting, threads, stopping, statuses, and logs.
  • Browser instance: navigation, clicks, text input, DOM interaction, and screenshots.
  • Project data: variables, lists, tables, and static data.

The complete operation reference, interactive OpenAPI contract, error codes, and versioning policy are available in the PublicApi documentation.

7. Example Prompts​

Start with read-only requests: this lets you see how well the assistant understands the project without risking any changes.

Understand the project:

Describe step by step what the open project does. Where can it fail?

Build a path from the start block to the block that submits the form.

Show all incoming and outgoing connections of the selected block and where the error branches go.

Edit and debug:

After the login block, add a captcha check. If a captcha appears, route
execution to a separate retry branch.

Find blocks that have no OnError branch filled in, and suggest what to put there.

Save the project and confirm that the file on disk was updated.

Run and investigate failures:

Run this task with 3 threads, wait for it to finish, and show which block
it failed on and what the variable values were at that moment.
tip

Before making changes through the assistant, save a copy of the project: changes can arrive quickly and in batches.

8. Troubleshooting​

SymptomCauseWhat to Do
The client says no tools are availableThe server is not running, or the configuration was added to the wrong programCheck the server window and restart the client; the configuration is loaded at startup
401 errorThe key is invalid or was not passed correctlyMake sure the entire key is specified without extra spaces or quotation marks. If the key is lost, issue a new one
403 errorThe key does not have the required permission or tierThe error message specifies exactly what is missing. Issue a key with the required scopes and a tier above T0
409 error when closing the projectThe project has unsaved changesSave the project or explicitly pass discardUnsavedChanges: true
The server does not start because the port is in useThe port is being used by another copy of the server or a third-party programClose the extra copy. Do not use the 6107-6113 range; it is reserved for internal services
The assistant cannot see the projectProjectMaker is closed or no project is open in itStart ProjectMaker, open the project, and try again
The archive cannot be downloaded from GitHubYour provider imposes restrictions in your regionTry a different connection. If that does not work, contact support and they will send you the file directly