agentcore-harness-builder SKILL.md skillA
agentcore-harness-builder from timwukp/agent-skills-best-practice is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add timwukp/agent-skills-best-practice/agentcore-harness-builder@git:20260813.e5fc421Pins git:20260813.e5fc421 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- timwukp/agent-skills-best-practice
- Path
skills/skills/agentcore-harness-builder/SKILL.md- Versions recorded
- 5
- Latest version
- git:20260813.e5fc421, committed Aug 13, 2026
- First version recorded
- Jun 15, 2026
- Size
- 23,551 bytes
- Repository stars
- 12
- License
- MIT
Build production-ready AWS Bedrock AgentCore Harness agents end to end — declarative model + prompt, managed/BYO Memory, built-in Browser, Code Interpreter, Web Search and Knowledge Bases (RAG), Gateway/MCP tools + rate limits, inline functions, Skills (incl. AWS catalog), versioning + endpoints, advanced config (truncation, limits, lifecycle, network, inbound auth, BYO S3 Files/EFS mounts or container), Observability (log delivery), Evaluations, Optimizations, Identity…
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# AWS Bedrock AgentCore Harness Builder ## Overview A **Harness** is AWS Bedrock AgentCore's declarative, fully-managed way to run an agent. You hand AWS a JSON configuration — model, system prompt, tools, memory, skills, limits — and AWS runs the agent loop (Strands under the hood) inside a per-session Firecracker microVM with its own filesystem and shell. No container to build by default (a custom image via `environmentArtifact` is an advanced option), no agent loop to write. You change behavior by changing config, not redeploying code, and you can override model/prompt per invocation. This skill builds a **complete, best-practice Harness use case** that exercises every AgentCore capability the user needs, wired correctly the first time. Harness is **generally available** (GA 2026-06-17, all AWS Commercial Regions where AgentCore is available, plus GovCloud US-West since 2026-08; only Payments remains preview), but it is still fast-moving and the real API shapes often differ from the published docs — this skill encodes the hard-won facts so you don't rediscover them through validation errors. ### The two-plane mental model (internalize this first) …
Read the whole file at its exact version.
How to install
mdr add timwukp/agent-skills-best-practice/agentcore-harness-builder@sha256:d98e3df0d49e16d1The line at the top of this page pins the label git:20260813.e5fc421, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_l7vrhmlgw7rhc2ja)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 5 versions of this file, between Jun 15, 2026 and Aug 13, 2026, about one every 15 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260813.e5fc421 latest | 2026-08-13 | e5fc421 | 23,551 B | A | view · diff |
| git:20260813.c0f596a | 2026-08-13 | c0f596a | 22,103 B | A | view · diff |
| git:20260813.a836c74 | 2026-08-13 | a836c74 | 22,408 B | A | view · diff |
| git:20260727.31937ac | 2026-07-27 | 31937ac | 20,911 B | A | view · diff |
| git:20260615.311560e | 2026-06-15 | 311560e | 17,921 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (23551 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
timwukp/agent-skills-best-practice · 12 stars · license MIT · pushed 2026-09-16 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_l7vrhmlgw7rhc2ja GET https://markdownregistry.com/api/v1/resolve?ref=timwukp/agent-skills-best-practice/agentcore-harness-builder GET https://markdownregistry.com/api/v1/blob/d98e3df0d49e16d1bbbab420a2a43671e0a4631eda4369a0bebff14bdc418f0d
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.