Capture architectural decisions made during Claude Code sessions as structured ADRs. Auto-detects decision moments, records context, alternatives considered, and rationale. Maintains an ADR log so future developers understand why the codebase is shaped the way it is.

Architecture Decision Records Capture architectural decisions as they happen during coding sessions. Instead of decisions living only in Slack threads, PR comments, or someone's memory, this skill produces structured ADR documents that live alongside the code. When to Activate User explicitly says "let's record this decision" or "ADR this" User chooses between significant alternatives (framework, library, pattern, database, API design) User says "we decided to..." or "the reason we're doing X instead of Y is..." User asks "why did we choose X?" (read existing ADRs) During planning phases when architectural trade offs are discussed ADR Format Use the lightweight ADR format proposed by Michael Nygard, adapted for AI assisted development: Workflow Capturing a New ADR When a decision moment is detected: 1. Initialize (first time only) — if docs/adr/ does not exist, ask the user for confirmation before creating the directory, a README.md seeded with the index table header (see ADR Index Format below), and a blank template.md for manual use. Do not create files without explicit consent. 2. Identify the decision — extract the core architectural choice being made 3. Gather context — what problem prompted this? What constraints exist? 4. Document alternatives — what other options were considered? Why were they rejected? 5. State consequences — what are the trade offs? What becomes easier/harder? 6. Assign a number — scan existing ADRs in docs/adr/ and increment 7. Confirm and write — present the draft ADR to the user for review. Only write to docs/adr/NNNN decision title.md after explicit approval. If the user declines, discard the draft without writing any files. 8. Update the index — append to docs/adr/README.md Reading Existing ADRs When a user asks "why did we choose X?": 1. Check if docs/adr/ exists — if not, respond: "No ADRs found in this project. Would you like to start recording architectural decisions?" 2. If it exists, scan docs/adr/README.md index for relevant entries 3. Read matching ADR files and present the Context and Decision sections 4. If no match is found, respond: "No ADR found for that decision. Would you like to record one now?" ADR Directory Structure ADR Index Format Decision Detection Signals Watch for these patterns in conversation that indicate an architectural decision: Explicit signals "Let's go with X" "We should use X instead of Y" "The trade off is worth it because..." "Record this as an ADR" Implicit signals (suggest recording an ADR — do not auto create without user confirmation) Comparing two frameworks or libraries and reaching a conclusion Making a database schema design choice with stated rationale Choosing between architectural patterns (monolith vs microservices, REST vs GraphQL) Deciding on authentication/authorization strategy Selecting deployment infrastructure after evaluating alternatives What Makes a Good ADR Do Be specific — "Use Prisma ORM" not "use an ORM" Record the why — the rationale matters more than the what Include rejected alternatives — future developers need to know what was considered State consequences honestly — every decision has trade offs Keep it short — an ADR should be readable in 2 minutes Use present tense — "We use X" not "We will use X" Don't Record trivial decisions — variable naming or formatting choices don't need ADRs Write essays — if the context section exceeds 10 lines, it's too long Omit alternatives — "we just picked it" is not a valid rationale Backfill without marking it — if recording a past decision, note the original date Let ADRs go stale — superseded decisions should reference their replacement ADR Lifecycle proposed : decision is under discussion, not yet committed accepted : decision is in effect and being followed deprecated : decision is no longer relevant (e.g., feature removed) superseded : a newer ADR replaces this one (always link the replacement) Categories of Decisions Worth Recording Category Examples Technology choices Framework, language, database, cloud provider Architecture patterns Monolith vs microservices, event driven, CQRS API design REST vs GraphQL, versioning strategy, auth mechanism Data modeling Schema design, normalization decisions, caching strategy Infrastructure Deployment model, CI/CD pipeline, monitoring stack Security Auth strategy, encryption approach, secret management Testing Test framework, coverage targets, E2E vs integration balance Process Branching strategy, review process, release cadence Integration with Other Skills Planner agent : when the planner proposes architecture changes, suggest creating an ADR Code reviewer agent : flag PRs that introduce architectural changes without a corresponding ADR

architecture-decision-records