Decision infrastructure for coding agents
Decision infrastructure gives coding agents a durable, reviewable and enforceable record of what a software team has already decided.
Decision infrastructure
Practical notes on giving coding agents durable project context, reproducible decisions and constraints that mean what they claim.
Decision infrastructure
Decision infrastructure is the repository-level system that records an engineering decision, makes the relevant decision retrievable by coding agents, and verifies any machine-checkable constraint against the code. It turns project memory from optional prose into maintained engineering infrastructure.
Read the field note01
Decision infrastructure gives coding agents a durable, reviewable and enforceable record of what a software team has already decided.
Decision drift happens when later code changes gradually stop reflecting an engineering decision that the team still considers valid.
Coding agents often reverse valid architectural decisions because the rationale and rejected alternatives are missing from the task context.
Negative decisions document approaches a team deliberately rejected so people and coding agents do not repeatedly reintroduce them.
Repository-local decisions travel with the code, inherit review and remain available across agent vendors and execution environments.
Record rejected approaches with scope, evidence and reconsideration conditions so coding agents do not rediscover the same failure.
An agent-ready ADR adds explicit scope, lifecycle, rejected alternatives, retrieval terms and machine-checkable consequences.
Migrate decisions by preserving identifiers and provenance, then deliberately rescoping, accepting or rejecting them in the destination repository.
02
Use layered instructions, repository decision records and deterministic retrieval to give coding agents persistent context without one enormous prompt.
AGENTS.md and CLAUDE.md guide particular coding agents; ADRs preserve durable decisions. They solve related but different problems.
Agent instruction files shape model behaviour, but they do not prove that a patch complies with an engineering decision.
Coding agents remember architectural decisions reliably only when the repository can retrieve a current, cited record for each task.
Keep decisions in one vendor-neutral repository record and use each agent's instruction file only as a route into that shared authority.
A practical AGENTS.md should teach Codex how to work in a repository while routing durable engineering decisions to their authoritative records.
Use CLAUDE.md to route Claude Code toward current architecture decisions, not to duplicate an entire decision history.
Multiple agents stay consistent when they share authority, retrieval and verification—not when prompts happen to resemble one another.
03
ADRs become more useful to coding agents when they are validated, discoverable by task language, lifecycle-aware and connected to checks.
Requirements as code makes important product constraints versioned, validated, discoverable and testable alongside the implementation.
04
RAG is flexible for broad knowledge discovery; deterministic retrieval is useful when engineering decisions need reproducible results and citations.
A read-only MCP boundary lets coding agents discover and cite accepted decisions without silently changing the authority they depend on.
05
Enforce an architectural decision in CI by translating one objective consequence into a deterministic check linked to the accepted record.
Deterministic checks make agent governance reproducible by evaluating explicit constraints without asking another model for a compliance opinion.
06
A worked example showing how to record, retrieve and enforce a 30-day account-restoration decision for coding agents.
Use this checklist to assess whether a repository gives coding agents durable decisions, reproducible retrieval and honest enforcement.
Instruction files, ADRs, MCP servers, RAG and CI policy engines govern different stages; dependable systems combine them without confusing guidance with proof.
A reproducible benchmark can measure whether instructions improve agent behaviour and whether deterministic checks catch the violations that remain.
07
Record the database convention, expose its rationale before planning, and enforce only the structural consequences that CI can prove.
Test observable outcomes—decision retrieval, citations, commands, policy results and patch behaviour—rather than asking the agent whether it complied.
Decision provenance links an AI-assisted change to the reviewed records, repository state and evidence that governed it.
08
Repository-native context is the safer authority layer for engineering decisions; RAG remains useful for broader discovery across large, mixed corpora.