diff --git a/AGENTS.md b/AGENTS.md
new file mode 100644
index 0000000..23b6ff8
--- /dev/null
+++ b/AGENTS.md
@@ -0,0 +1,29 @@
+# AGENTS.md
+
+This file provides guidance to AI agents when working with code in this repository.
+
+## Project Overview
+
+`tar-diff` is a Go library and CLI toolset for diffing and patching tar files, primarily used for efficient distribution of OCI container images.
+
+## Agent Workflow Guidelines
+
+- **For simple changes**: Propose a short plan and ask a human to review it before you start implementing it.
+- **Never assume or guess** intent or meaning. If instructions, code, or documentation are ambiguous, ask for clarification.
+- **If you find a potential bug or security issue** in the code, inform the developer.
+- **Follow development conventions**: All code style, commit formatting, and testing requirements are in [`CONTRIBUTING.md`](CONTRIBUTING.md).
+
+## AI Permissions
+
+- **Always allowed**: Read any file, run linting commands (`make validate`, `golangci-lint`), search GitHub issues and PRs, analyze logs and test output.
+- **Safe to change**: Log messages, comments, variable names, code formatting.
+- **Ask first**: Anything that affects core algorithms, file format, or cross-platform compatibility. This includes: documentation files (`README.md`, `CONTRIBUTING.md`, `AGENTS.md`), test assertions, linting config (`.golangci.yml`), refactoring, binary diff and patch logic (`pkg/tar-diff/`, `pkg/tar-patch/`), file format specification (`file-format.md`), CLI interface changes (`cmd/`), build configuration (`Makefile`, `.goreleaser.yml`), CI workflows (`.github/workflows/`), dependency changes (`go.mod`), platform-specific code (`cmd/tar-diff/tmpdir_*.go`).
+- **Never**: Push directly to `main`, commit compiled binaries (`tar-diff`, `tar-patch`), break cross-platform compatibility, modify the tardiff file format without approval, log or hardcode sensitive information.
+
+## Platform Requirements
+
+Code must work on Linux (x86_64, ARM), macOS (ARM), and Windows (x86_64).
+
+## File Format
+
+For tardiff file format work, see [`file-format.md`](file-format.md) for the complete binary format specification.