Strands Agents is an open-source SDK for building and running AI agents in Python and TypeScript. Developers use it to create agents with model providers, tools, lifecycle controls, memory, sessions, streaming, tracing, and evaluations, and the catalogue includes add-ons for its agent-building workflow.
Borrowing it
Nothing to install: this file belongs to strands-agents/harness-sdk. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/strands-agents/harness-sdk/main/AGENTS.mdgit clone --depth 1 https://github.com/strands-agents/harness-sdkWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/strands-agents/harness-sdk/agents-md)<a href="https://agentmods.dev/instructions/strands-agents/harness-sdk/agents-md"><img src="https://agentmods.dev/badge/instructions/strands-agents/harness-sdk/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/strands-agents/harness-sdk/agents-md"><img src="https://agentmods.dev/badge/instructions/strands-agents/harness-sdk/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.03101 | $0.03101 |
| Opus 5.5 | $0.01240 | $0.01240 |
| Sonnet 5.5 | $0.00620 | $0.00620 |
| Haiku 4.5 | $0.00310 | $0.00310 |
Grade A, and why
harness-sdk AGENTS.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 109 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent Development Guide - Strands Agents Monorepo
This document provides guidance for AI agents working in the Strands Agents monorepo. For human contributor guidelines, see CONTRIBUTING.md.
This file is shared by agents with different goals — writing code, opening PRs, helping contributors — and is organized by task.
Context
Monorepo Layout
strands-agents/
├── harness-py/ # Python Strands harness (hatch) — see harness-py/AGENTS.md
├── harness-ts/ # TypeScript Strands harness (npm) — see harness-ts/AGENTS.md
├── strands-cli/ # strands CLI (npm) — see strands-cli/AGENTS.md
├── strands-py/ # Python SDK (hatch) — see strands-py/AGENTS.md
├── strands-ts/ # TypeScript SDK (npm workspace) — see strands-ts/AGENTS.md
├── strands-mcp/ # MCP server with Strands docs for coding agents (hatch)
├── site/ # Documentation site (Astro) — see site/AGENTS.md
├── team/ # Governance + cross-SDK process (tenets, decisions, API bar-raising, PR & compatibility guidelines, designs/ proposals)
├── test-infra/ # CDK stack for integ tests that require provisioned AWS infra
├── .agents/ # Agent skills and references
├── package.json # npm workspace root
└── .github/workflows/ # CI (ci.yml is the merge gate)
Determine which sub-project you're in and follow its conventions — each has its own AGENTS.md.
Where the "why" lives: team/
Before designing a feature or changing an API, read the relevant context in team/. It captures the reasoning the code itself doesn't:
team/designs/— RFC-style proposals for significant features (numberedNNNN-*.md). The richest source of architectural context: problem framing, the chosen approach, alternatives considered, and consequences. If you're touching a major subsystem, find its design doc first.team/DECISIONS.md— lightweight architecture decision records for smaller calls.team/TENETS.md— the principles a contribution should align with.team/API_BAR_RAISING.mdandteam/FEATURE_LIFECYCLE.md— the bar and process for API changes and feature deprecation.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 9d ago Changed · +5 tokens per session bed0d611e382
- 16d ago Changed · +4 lines · +92 tokens per session e27c229f6e6a
- 29d ago Changed · +2 lines · +224 tokens per session 5fa86de3871d
- 2mo ago First seen · 103 lines · 2,780 tokens per session scan A 86a118214015
harness-sdk AGENTS.md is an instructions file published in the GitHub repository strands-agents/harness-sdk (8,996 stars, last pushed today), licensed Apache-2.0. It adds 3,101 tokens to every session, about $0.0124 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
deepseek-harness AGENTS.md
AGENTS.md instructions for deepseek-ai/deepseek-harness, covering agents.md, pre-stable apis and released session data, repository layout, commands and host sandbox failures.