---
title: "What is a persona compiler? | AdBuyMCP"
description: "The deterministic stage that turns one described audience into the native targeting specification each channel accepts."
url: "https://adbuymcp.com/glossary/persona-compiler"
---

[Home](https://adbuymcp.com/) / [Glossary](https://adbuymcp.com/glossary) / Persona compiler

AdBuyMCP's own vocabulary

# What is a persona compiler?

The deterministic stage that turns one described audience into the native targeting specification each channel accepts, with a fidelity score and a lawful-basis manifest. Depending on the channel, that specification is segment identifiers, attribute combinations, show allowlists, venue packs or keyword seeds.

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What it means here

## Here is what the term means for a UK buyer

The definition above holds anywhere. Buying media in the UK adds the detail below, including where AdBuyMCP does something different.

The design splits the work between a language model and registry code. The model extracts semantics from the brief: what kind of person, which interests, which geography, what intent. It never emits a vendor segment identifier. Deterministic registry code then matches those semantics against catalogue keywords by whole-token overlap (exact token equality, never substring containment, so 'ai' cannot match 'sustainability') and emits known identifiers. That is why a compiled plan can be audited line by line, why a hallucinated segment cannot reach a buy, and why the same brief compiles the same way twice.

Read next

- [The four channels in an awareness plan Channels](https://adbuymcp.com/channels)
- [What UK awareness advertising costs Cost](https://adbuymcp.com/cost)
- [How the compilers produce a score Guide](https://adbuymcp.com/guides/what-a-fidelity-score-is)

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Related terms

## These terms sit next to this one

Most confusion in media buying comes from two adjacent terms being used interchangeably, so these are the neighbours worth reading next.

- ### [Fidelity score](https://adbuymcp.com/glossary/fidelity-score)
  A published score out of 100 answering one question: how much of an audience definition survives translation into a channel's native targeting words. It describes that translation, so it makes no forecast of reach or performance and says nothing about the quality of the media.
- ### [Audience segment](https://adbuymcp.com/glossary/audience-segment)
  A named group of people a seller will let you target, defined by some combination of demographics, behaviour, stated interest or inferred intent, and identified in a buying system by a specific identifier.
- ### [Lawful-basis manifest](https://adbuymcp.com/glossary/lawful-basis-manifest)
  A record attached to every compiled channel plan naming each data source used, the lawful basis it relies on, the conditions that come with it, and the warnings raised while compiling. The compiler writes it automatically as it builds the plan.

Same group

## These terms are also in AdBuyMCP's own vocabulary

These are the terms AdBuyMCP either coined or uses more strictly than the category does.

- [Exposure ledger](https://adbuymcp.com/glossary/exposure-ledger)
- [Evidence ledger](https://adbuymcp.com/glossary/evidence-ledger)
- [Model Context Protocol (MCP)](https://adbuymcp.com/glossary/mcp)

[All 81 terms](https://adbuymcp.com/glossary)