Field notes on the marketing harness
One post per feature: how to put your coworkers and bots on one team, drive it from MCP, and orchestrate every flow. Written for marketers and the people who build with them.
What is a marketing harness?
A marketing harness puts every coworker and every bot on one team, with MCP as the interface and an orchestration and visualization layer underneath. Here is what that means.
MCP-native marketing
MCP-native marketing means every TrailGuide capability is a tool you call in plain language from Claude, and the same tools run for your agents too.
Marketing from the command line
Marketing from the command line: the TrailGuide CLI pipes extract, personalize, and journey deploy into one scriptable command you can review in pull requests.
Connect any data source
Connect any data source to TrailGuide: it introspects your warehouse or product database and maps tables to a semantic model, so segments run on your real data.
Model-driven segments
Model-driven segments let you describe an audience in plain language; TrailGuide compiles it to SQL against your semantic model and fails closed when unsure.
Boolean segment composition
Boolean segment composition builds audiences from real logic: match ANY (OR) or ALL (AND) of your conditions, exclude with NOT, and add range operators safely.
Bring your own model (BYOM)
Bring your own model (BYOM) connects your own LLM from any of seven providers to power all content generation in TrailGuide, with keys encrypted at rest.
Multi-step journeys with real waits and exits
A multi-step journey enrolls a user from a trigger, alternates sends and waits, and exits them the moment any exit criterion matches, all shown live.
Event triggers that fire on the moment
Event triggers watch for a row change, threshold, burst, or segment join and fire at an offset you set, turning reactive campaigns into configuration.
Personalization as a live API endpoint
A personalization endpoint takes a user or content key and returns personalized JSON for email, push, or in-app, with live preview and ready snippets.
Agentic copy that stays inside your rules
Agentic copy rewrites itself on every send inside hard guardrails you set, with banned words, required elements, batched variants, and human approval.
Delivery across every channel
Delivery across every channel sends one message over push, email, SMS, Slack, or a safe custom HTTP call, through the providers you already run.
Optimization lineage
Optimization lineage treats every message as a hypothesis, branches it into variants, measures each one against its parent, and recommends the next test to run.
Global holdout lift
A global holdout is a control group held back from messaging so you can measure true incremental lift, per campaign and globally, not just vanity opens.
Frequency and engagement caps
Frequency and engagement caps limit how often you message a user and pull back sends to disengaged users, protecting the inbox and your sender reputation.
Master Blaster broadcasts
Master Blaster turns a winning journey into a one-time broadcast to a large audience, inside your guardrails, with resolving deep links and a changelog.
The agent fleet
The agent fleet is a set of autonomous AI coworkers that surface opportunities and draft marketing tasks. They are recommend-only, so a human always decides.
The Workflow task tracker
The Workflow tab is a shared board of tasks for people and bots. Every task has an owner, can tag any coworker, and handoffs mirror to email and Slack.
Scheduled digests
Scheduled digests are daily briefs you set up through your own Claude MCP: your tasks or campaign performance from the last 24 hours, delivered privately.
Customer Skills
Customer Skills are versioned rule bundles that capture your brand voice, dos and don'ts, and offers, then fork into A/B variants you can test in real sends.