sundial

Decision-aware coding autonomy for staff-engineer-supervised AI work. Sundial turns engineer judgment into reusable agent context by storing accepted decisions as plain markdown Decision Records (DRs) inside your project.

When an agent encounters a consequential choice without precedent, it writes a candidate DR instead of silently inventing a new rule. You review candidates in a file-backed Candidate Inbox (or in the companion VS Code extension), accept or reject them, and retire older DRs as they age out. Accepted DRs become durable project memory that the next agent run consults before designing or coding.

• Open source, file-backed, no vendor lock-in
• One-line install
• Works with Claude Code and Codex CLI off the shelf
• Companion VS Code extension for the Candidate Inbox

Install

npm install -g sundial

Requires Node.js >= 20.

Quickstart

Initialize a project:

sundial init --root /path/to/project --claude --codex

init always creates .sundial/ and starter domains. Runtime assets are opt-in:

• --claude writes missing Claude Code project assets to .claude/skills/ and .claude/CLAUDE.md from CLI templates.
• --codex writes missing Codex project assets to .agents/skills/ and AGENTS.md from CLI templates.
• Pass both flags to bootstrap both runtimes.

Refresh installed skill files later without rerunning store init:

sundial update --claude --codex

The update command discovers the nearest ancestor .sundial store by default; pass --root /path/to/project to target a specific project. Sundial-owned instruction blocks in files such as AGENTS.md and .claude/CLAUDE.md are repaired or refreshed without overwriting user-authored content outside those blocks.

How it works

1. Retrieve precedent. Before design or coding, the agent consults accepted DRs.
2. Create candidates. When the agent hits a consequential choice with no precedent, it writes a candidate DR.
3. Review the inbox. The engineer edits, accepts, or rejects candidates and retires DRs that no longer apply.
4. Improve future work. Accepted DRs become durable project memory.

project/
  .sundial/
    domains.md
    drs/
      accepted/
        adr-001-testing-strategy.md
        dr-014-agent-permissions.md
      candidates/
        cand-027-error-boundaries.md
      rejected/
      retired/

Commands

sundial init --root <path> [--claude] [--codex]
sundial update --claude --codex
sundial status
sundial bootstrap --provider claude
sundial bootstrap --provider codex
sundial domains

sundial dr list [--status accepted]
sundial dr get DR-0001
sundial dr retrieve --domain <domain>
sundial dr disable DR-0001
sundial dr enable DR-0001
sundial dr retire DR-0001 [--by DR-0002]
sundial dr promote CAND-0003 --from rejected

sundial candidate create --title "Decision title" --domain <domain> --decision "Do the thing"
sundial candidate list
sundial candidate show CAND-0001
sundial candidate accept CAND-0001
sundial candidate reject CAND-0001 --reason "Covered by DR-0001"
sundial candidate retire CAND-0001 [--by DR-0001]

Notes:

• Enabled accepted DRs are the only precedent retrieved by dr retrieve.
• Candidate DRs can include a proposed domain with a description; accepting the DR appends that proposal to .sundial/domains.md.
• DRs can include a ## Appendix section for human-facing explanatory context; short and medium retrieval omit it.

VS Code

A companion VS Code extension contributes a Sundial activity bar view with a Candidate Inbox, a Sundial: Initialize Project command, and a Sundial: Bootstrap Decisions command. Bootstrap invokes the selected Claude or Codex CLI and requires it to create DR candidates through sundial candidate create, so candidates use the normal lifecycle path. The extension expects the sundial CLI to be available on PATH.

Links

• Source: https://github.com/bjackson-arcridge/sundial
• Issues: https://github.com/bjackson-arcridge/sundial/issues
• About: https://arcridgelabs.com/sundial.html

License

Apache 2.0