AI

A language model is a function from text to text. You send it a list of messages, it returns one message, and nothing else happens. It cannot read your disk, check the clock, remember your previous question, or run the tool it just asked for. Every capability an AI product appears to have belongs to the program wrapped around the model. That program is the harness: the code that builds each request, executes the tools the model asks for, and decides what the model is shown in the first place. ...

An MCP server that adds two numbers has no opinion about who is calling it. One that posts to a social account has to answer a question before it can do anything at all: whose account? There are two workable answers. You can build a multi-tenant server that authenticates every caller and looks up the account they own, which is the shape Add GitHub OAuth to a FastMCP Server builds. Or you can build one process that acts as exactly one account, reads that account out of its own environment, and runs on the same machine as the client calling it. ...

An agent is a program that lets a language model decide which of your functions to run, runs them, and hands back the results until the model says it is done. There is no framework in this article and no API key. By the end you will have a coding agent on your own machine that lists, reads and writes files inside a directory you choose, asks permission before running a shell command, and stops instead of spinning when the model gets stuck. The core agent is a few hundred lines of Python, plus a model-free pytest suite, for a 795 MiB model. ...

Hermes Agent installs from a shell script in a couple of minutes. Installing it the same way twice, a year apart, on a machine you have since forgotten the details of, is the harder problem — and it is the one Ansible solves. This article builds one role that installs Hermes on two Macs that differ in the ways that actually matter: devbot5 — the Mac you are typing on minime — a headless Mac mini Connection local, no SSH at all ssh Runs as your login account a dedicated service account launchd job LaunchAgent in your home LaunchDaemon in /Library API bound to 127.0.0.1 0.0.0.0 Those last two rows are what this article is about. A headless Mac has no one logged in, so there is no GUI session for a LaunchAgent to live in and the job has to be a LaunchDaemon that starts at boot and drops privileges. A laptop joins hotel and coffee-shop networks, so binding an agent’s API to every interface there would publish a shell to whoever else is on that LAN. ...

Hermes Agent is Nous Research’s open-source (MIT) agent runtime: one agent with persistent memory that you can reach from a terminal or from a chat platform, backed by whichever model provider you point it at. Unlike an agent library, it ships as an installed program with its own config directory, a messaging gateway, and a command approval layer, so most of the work in getting started is deciding what it is allowed to do rather than writing code. ...

Add Per-Plan Rate Limiting to a FastMCP Server on macOS closes its troubleshooting with “back it with Redis (shared, atomic counters) if you run several instances behind a load balancer”, and Add Observability to a FastMCP Server on macOS adds a /health endpoint “for load balancers”. Neither article puts a load balancer in front of anything. This one does, and the first thing that happens is that the server stops working. ...

Generate Synthetic JSON Requests to Test an API on macOS built two generators and a CLI that fires batches at an order-intake API. This article puts the same generators behind an MCP server, so an agent can preview a payload, check the target, and trigger a batch by asking for one. Wrapping a generator in tools is the easy half. The half worth attention is the control surface: which decisions the caller gets to make and which ones the server keeps. A model that can pick the destination of a traffic generator is a server-side request forgery primitive with a friendly name, and a model that can pick the batch size can turn one sentence into fifty thousand POSTs. Here the target comes from the environment and the batch size is capped, so the tools stay useful without handing over either decision. ...

Most teams have a procedure that only lives in someone’s head. Cutting release notes, triaging a breaking change, prepping an on-call handoff: five steps, done slightly differently every time, and badly the week the person who knows them is on vacation. MCP gives you three primitives to fix that, and the interesting one is the least used. Tools are called by the model. Resources are read for context. Prompts are chosen by a person: named, parameterized templates a client surfaces as a slash command. That makes a prompt the natural home for a procedure — the user picks it, fills in one argument, and the model runs the same five steps in the same order every time. ...

A resource that returns a picture is the most demanding shape an MCP resource takes. It has to survive base64 encoding, arrive with a MIME type the client will accept, stay small enough to attach, and — if the picture is meant to reflect something live — return different bytes the next time the same URI is read. Serve Resources Well from an MCP Server on macOS covered the shapes of resources with an eight-byte PNG magic number standing in for a binary body. This article replaces that stub with a real image: a bar chart rendered on every read from state that anything can change, packaged so uvx runs it from a local directory, and wired into opencode so a model can read it, watch it change, and read it again. ...

opencode attaches an MCP server in a single command, with no config file to hand-edit and no JSON to get wrong. Everything after the -- separator is the command that launches the server, and because uvx resolves the package on first launch, there is nothing to install beforehand either: opencode mcp add hello -- uvx mcp-hello-server This tutorial uses that command to attach mcp-hello-server — a small FastMCP server on PyPI exposing two tools, server_info and greet — then drives it from a free model. You will confirm the server connects, prove the launch command works without involving a model at all, pin the same server to a single project instead of your whole machine, and finally ask North Mini Code Free to say hello to Alice in Japanese. ...