Public spec library
The agent does not run on opacity.
Architecture, security, concepts, and the vision behind YiG — written as durable articles you can forward to your security reviewer, your compliance officer, or the controller next desk over.
User manuals
Free downloadable setup, deployment, login, activation, and troubleshooting guides for the Yigcore Excel Add-in.
- Excel Add-in PRD Deployment and Activation Guide PDF · English Download the production manifest, deploy it in Excel or Microsoft 365 Admin Center, sign in, activate trial or paid license, configure providers, and troubleshoot.
- Excel Add-in PRD 部署与激活手册 PDF · 中文 下载生产 manifest，在 Excel 或 Microsoft 365 管理中心部署，完成登录、试用或付费许可证激活、Provider 配置和常见问题排查。
Vision
Why YiG exists, and what kind of product we are building.
- YiG product line 2026-05-13 A guided tour of the YiG suite — Thinker, Enterprise, Finance, and the Office Add-ins — and which one fits which team.
- Computer as instrument, not lifestyle product 2026-05-10 Why YiG looks more like Bloomberg than Notion, and what that means for finance teams.
- The close is not a process 2026-05-11 Why month-end close is a judgment-intensive reckoning, not a task list, and what that means for the software that touches it.
- Against the co-pilot metaphor 2026-05-11 The co-pilot frame is ubiquitous in enterprise AI. It is the wrong frame for finance. The metaphor you choose determines the product you build.
Concepts
How to think about YiG — the patterns and principles that govern every workflow.
- You drive. YiG drafts. — A HITL design principle 2026-05-10 Human-in-the-loop is not a feature bolted onto YiG — it is the architecture. Why every write waits for a reviewer, and what that choice costs and buys.
- Why the spreadsheet is still winning 2026-05-11 Finance teams keep their workbooks not because they have not found a better tool, but because the workbook is the right primitive. What that demands of agents.
- The yellow flag 2026-05-11 Why designing AI uncertainty as a first-class product feature is the correct architectural choice — not a limitation to hide.
- How the reviewer gate works 2026-05-11 The architectural component that enforces human-in-the-loop. What it enforces, how it is built, and why it cannot be bypassed by configuration.
- Workflow templates explained 2026-05-11 What a workflow template is, how the planner executes it, how templates handle edge cases, and how to read the output shape.
- The BYOK model 2026-05-11 What bring-your-own-key means for data handling, compliance, and model selection. Why YiG is not in the inference business.
- Run your first GL reconciliation 2026-05-11 A walkthrough of the GL reconciliation workflow from first invocation to approved output — what happens at each layer and what the reviewer sees.
- Connecting YiG Thinker to Slack 2026-05-11 How the Slack surface works: webhook setup, thread-based review flow, what the reviewer sees, and what gets logged.
- The surface contract 2026-05-16 Slack, Teams, Feishu, and Excel are not integration targets but the surface where work happens — and that changes what the agent owes them, and they it.
- What we don't cache and why 2026-05-16 Agent state is a trust decision before it is a performance decision. YiG rebuilds what should be auditable and persists only what survives review.
Architecture
How YiG is structured. Trust boundaries, layers, and what crosses each boundary.
- Architecture overview 2026-05-10 Four layers, clear trust boundaries, and what crosses each boundary. No internals.
- What the operator controls 2026-05-11 The full operator control surface: surfaces, workflows, model, reviewers, audit destination, and deployment topology. What is configurable and what is not.
- Deployment topologies in practice 2026-05-11 Local, customer cloud, and single-tenant managed — the tradeoffs between each topology, when to choose each, and how to migrate between them.
Security
Data residency, audit log, reviewer gate, and what we will not do.
- Security and data handling 2026-05-10 Where customer data lives, what YiG logs, how long any of it is kept, and the handling lines the architecture will never cross.
- Reading an audit log 2026-05-11 What each field in a YiG audit record means, how records chain together into a run trail, and how to use the trail in a downstream audit.
- The shape of an audit trail 2026-05-16 An audit trail is a reconstruction contract: recorded state should let an independent reviewer rebuild the decision that produced an output.
Specs
Public summaries of completed internal specifications.