Adr Author

ADR Author

When to use

You are the SA, drafting docs/architecture.md or revising it during change synchronization. You face a choice that would surprise a new engineer joining the project, or that involves a trade-off you'd want a successor to understand. Per CLAUDE.md §3.2: every non-trivial choice gets an ADR. This skill defines the format and the trigger.

Inputs and outputs

• Inputs: a candidate architectural choice and the alternatives you're weighing
• Outputs: a numbered ADR file under docs/decisions/, in the format in [references/template.md](./references/template.md)

When a choice is "non-trivial"

A choice deserves an ADR when at least one is true:

• It's a one-way door (hard to reverse later — pricing model, data partition strategy, primary key shape)
• It commits the team to a vendor or stack (Postgres vs DynamoDB, Stripe vs Adyen, REST vs gRPC)
• It contradicts a previous default (the team usually does X; for this feature we're doing Y)
• A reasonable engineer would assume the opposite default
• It encodes a trade-off (cost vs latency, simplicity vs flexibility, build vs buy)

If a choice is "the obvious thing the team always does," no ADR. If you can't tell, write the ADR — it's cheap.

Third-party dependency ADRs (require human Approver)

When the ADR introduces a third-party dependency that has not been approved in a prior ADR for this project, the ADR gains two required fields:

• Approver: — the Designated Dependency Approver named in SRS header per CLAUDE.md §2. Set by the user through the Orchestrator's NEEDS_CONTEXT clarification flow; never set by the agent.
• Approval-Date: — the date the human approved the choice.

Per CLAUDE.md §10 hard rule, you must NOT write the ADR with Status: Accepted until the human has approved. The flow:

1. While drafting architecture, you identify a needed third-party dependency.
2. Use .claude/skills/third-party-dependency-evaluation/SKILL.md to evaluate options.
3. Halt and return NEEDS_CONTEXT to the Orchestrator with the multi-choice proposal.
4. The Orchestrator relays to the Designated Dependency Approver.
5. The Approver picks an option.
6. Resume work. Write the ADR with Status: Accepted, Approver: , Approval-Date: .

Default-vendor ADRs are a sub-case: when the dependency is the org-level default per .claude/skills/solution-defaults/, the ADR's Approver field cites the skill rather than naming a per-project human:

Approver: Org Engineering Standards (per .claude/skills/solution-defaults/)
Approval-Date: 

Defaults are pre-approved at the org level; no NEEDS_CONTEXT is needed for the choice. See .claude/skills/solution-defaults/ for the table of pre-approved defaults and deviation conditions.

For non-dependency ADRs (e.g., "use event sourcing for the audit log", "primary-key UUIDv7 vs ULID"), the Approver field is not required. The ADR follows the normal Proposed → Accepted path with SA + reviewers.

When a later ADR depends on the same vendor approved by a prior ADR, cite the prior ADR's approval rather than re-triggering the flow:

Refs: ADR-0007 (approves Stripe for payments)

Procedure

1. Choose the next sequential number from docs/decisions/. Filenames: 0001-.md, 0002-.md, etc. Numbers are immutable; never renumber.
2. If the ADR introduces a new third-party dependency, follow the approval flow above before writing.
3. Use the template in [references/template.md](./references/template.md). Include Approver: and Approval-Date: if applicable.
4. Set Status to Proposed if the choice is still under review; Accepted once SA + reviewers agree (and the human Approver has confirmed for dependency ADRs).
5. Reference the ADR from the relevant section of docs/architecture.md (e.g., "Session storage: Postgres — see ADR-0007").
6. When a later decision supersedes this one, update both files: the new ADR cites Supersedes ADR-XXXX; the old ADR's Status changes to Superseded by ADR-YYYY (do not delete the old file).

Hard rules

• Never delete an ADR. Status changes preserve history; deletion erases it.
• Never renumber an ADR. References to ADR-0007 in code comments and docs would silently rot.
• Status Accepted requires explicit reviewer sign-off (SA can self-accept low-stakes non-dependency ADRs; high-stakes choices need a second engineer's review).
• For third-party-dependency ADRs: Accepted is impossible without the Approver field populated. The human is the gate.
• An ADR without a Consequences section is incomplete — every choice has consequences, including good ones. List both.
• An ADR without Alternatives Considered is incomplete. If you didn't consider alternatives, you didn't make a decision; you made a default.

References

• [references/template.md](./references/template.md) — copy-paste ADR template, including the Approver fields and worked examples
• CLAUDE.md §3.2 — SA exit criteria (every non-trivial choice → ADR)
• CLAUDE.md §10 — hard rule that third-party dependencies require human Approver
• .claude/skills/solution-defaults/SKILL.md — org-level pre-approved defaults; check before triggering the third-party-dependency-evaluation flow
• .claude/skills/third-party-dependency-evaluation/SKILL.md — what counts as third-party, dimensions to weigh, NEEDS_CONTEXT prompt format
• Michael Nygard's original ADR essay (external) — the format here follows his

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: evolplus
• Source: evolplus/talos
• License: Apache-2.0

Install and usage instructions live in the source repository linked above.