In short:
ak-mcp-builderbuilds an MCP server so AI can use your service or API: it finishes one tool end to end, tests it with a real client, and only then adds more tools. It publishes to the MCP Registry only when you ask. It does not configure clients and does not call existing servers.
Disclosure: I maintain AgentKit and have an affiliate relationship with it: the AgentKit link in this post is an affiliate link; buying through it gets you 30% off.
Summary
Use it when you have a service or API and want AI to use it through MCP, when an old server needs to move to SDK v2, when you want a tool set reviewed, when you want to measure how well AI uses your tools, or when you want to publish a server to the MCP Registry. You do not need it to configure a client or to call tools on an existing MCP server.
flowchart LR
A["Service or API for AI to use"] --> B["ak-mcp-builder"]
B --> C["MCP server, tools tested for real"]
C --> D["Add tools when the workflow needs them"]
C --> E["MCP Registry, only when you ask"]
C --> F["Stop, report what is untested"]What to keep in mind:
| Concept | Question | Example |
|---|---|---|
| Contract of the first tool | What does the tool take, return, change, and need permission for? | crm_search_contacts takes query, limit, offset; returns one page with has_more; read-only; API key from an environment variable |
| Transport | Does the server run for one person on a machine, or for many over the network? | One person locally uses stdio; remote or many users use Streamable HTTP; no old HTTP+SSE |
| Annotations are only hints | Who actually blocks a destructive action? | readOnlyHint, destructiveHint only help the host UI; the server checks permissions itself and asks for confirmation before deleting |
| Two layers of testing | What evidence shows the server works? | Real calls with MCP Inspector or an SDK client; then a set of read-only questions run through a grading script |
If the project is on SDK v1, the skill keeps it there and only moves to v2 when you ask or when the feature you need requires v2. A registered tool or a clean tools/list does not count as done.
Sample prompt for a new server:
/ak-mcp-builder <service name>
Outcome: AI can find customers by name or email through an MCP tool.
Constraints: runs locally on my machine, API key read from the environment variable <VAR_NAME>.
Not doing: tools that edit or delete data.
Done when: calling the tool with MCP Inspector returns the right result.This skill has no flags. After the command name, you write the service or API to integrate, then the outcome, constraints and when it is done in the same prompt.
Below is the detailed version: the run flow, 6 situations with prompts, how to write the input, the change history by ak release, and common pitfalls. The detailed version and the interactive page are for subscribers. Your agent can also search them through the portal's MCP.
Opens when your account has subscriber access
This guide is for subscribers
Once your account has access, the full piece, the interactive visual and the agent call all open.
- Sign in or create a modernEngineer accountReading access belongs to your account email.
- Choose a plan on the pricing page1, 3 or 12 months, paid by VietQR bank transfer. Access opens about a minute after the money arrives.
- Or redeem a Facebook subscriber codePeople supporting the page on Facebook get an activation code by message each month.
Already a subscriber? Sign in to read.
Use this piece in your agent
Get an API keyCopy the text below and paste it into Claude Code, Codex or whichever agent you use. The agent reads the piece and checks it against the repo you have open.
Read "ak-mcp-builder: build MCP servers so AI can use your service" on modernEngineer and apply it to this repo.
1. Call the content_get tool of the modernengineer MCP server with locale "en", slug "ak-mcp-builder". If the modernengineer MCP server is not connected, stop and walk me through connecting it from https://modernengineer.dev/en/mcp.
2. Summarize the main steps of the piece and point out which apply to this repo.
3. Propose concrete changes and ask me before editing any file.Connect MCP in Claude Code (once)
claude mcp add --transport http modernengineer \
https://api.modernengineer.dev/mcp \
--header "Authorization: Bearer <API key>"Reading the full piece over MCP needs an API key from a subscriber account or one that bought this guide. Without access, the agent only gets the opening.
- Version
- v1.0.0
- Updated
- 22/10/2026
- Licence
- All rights reserved
- Slug
- ak-mcp-builder
