Cursor rule

1---
2description: "Extract a DDD-style ubiquitous language glossary from the current conversation, flagging ambiguities and proposing canonical terms. Saves to specs/UBIQUITOUS_LANGUAGE_LATEST.md. Use when user wants to define domain terms, build a glossary, harden terminology, create a ubiquitous language, or mentions \"domain model\" or \"DDD\"."
3alwaysApply: false
4---
5 
6# Define Language
7 
8Extract and formalize domain terminology from the current conversation into a consistent glossary, saved to `specs/UBIQUITOUS_LANGUAGE_LATEST.md`.
9 
10**Distinct from `model-domain` and `deepen-architecture`:** Use this skill to produce a canonical glossary of terms (words and definitions). Use `model-domain` to stress-test a plan through an interview that resolves domain model decisions. Use `deepen-architecture` to find module-level refactoring opportunities in the codebase.
11 
12> **HARD GATE** — Ubiquitous language is NOT optional. Every term in the domain that could be misunderstood must be glossed. Ambiguity = rework.
13 
14## Process
15 
161. **Scan the conversation** for domain-relevant nouns, verbs, and concepts
172. **Identify problems**:
18   - Same word used for different concepts (ambiguity)
19   - Different words used for the same concept (synonyms)
20   - Vague or overloaded terms
213. **Propose a canonical glossary** with opinionated term choices
224. **Write to `specs/UBIQUITOUS_LANGUAGE_LATEST.md`** in the working directory using the format below
235. **Output a summary** inline in the conversation
24 
25## Output Format
26 
27Write a `specs/UBIQUITOUS_LANGUAGE_LATEST.md` file with this structure:
28 
29```md
30# Ubiquitous Language
31 
32## Order lifecycle
33 
34| Term        | Definition                                              | Aliases to avoid      |
35| ----------- | ------------------------------------------------------- | --------------------- |
36| **Order**   | A customer's request to purchase one or more items      | Purchase, transaction |
37| **Invoice** | A request for payment sent to a customer after delivery | Bill, payment request |
38 
39## People
40 
41| Term         | Definition                                  | Aliases to avoid       |
42| ------------ | ------------------------------------------- | ---------------------- |
43| **Customer** | A person or organization that places orders | Client, buyer, account |
44| **User**     | An authentication identity in the system    | Login, account         |
45 
46## Relationships
47 
48- An **Invoice** belongs to exactly one **Customer**
49- An **Order** produces one or more **Invoices**
50 
51## Example dialogue
52 
53> **Dev:** "When a **Customer** places an **Order**, do we create the **Invoice** immediately?"
54> **Domain expert:** "No — an **Invoice** is only generated once a **Fulfillment** is confirmed."
55 
56## Flagged ambiguities
57 
58- "account" was used to mean both **Customer** and **User** — these are distinct concepts.
59```
60 
61## Rules
62 
63- **Be opinionated.** When multiple words exist for the same concept, pick the best one and list the others as aliases to avoid.
64- **Flag conflicts explicitly.** If a term is used ambiguously, call it out in "Flagged ambiguities" with a clear recommendation.
65- **Only include terms relevant for domain experts.** Skip names of modules or classes unless they have domain meaning.
66- **Keep definitions tight.** One sentence max. Define what it IS, not what it does.
67- **Show relationships.** Use bold term names and express cardinality where obvious.
68- **Group terms into multiple tables** when natural clusters emerge. One table is fine if terms are cohesive.
69- **Write an example dialogue.** 3–5 exchanges between a dev and domain expert showing terms used precisely.
70 
71## Re-running
72 
73When invoked again in the same conversation:
74 
751. Read the existing `specs/UBIQUITOUS_LANGUAGE_LATEST.md`
762. Incorporate any new terms from subsequent discussion
773. Update definitions if understanding has evolved
784. Re-flag any new ambiguities
795. Rewrite the example dialogue to incorporate new terms
80