Context & Tools is an independent developer notebook focused on practical Anthropic application development.
The goal is simple: help U.S. developers, indie hackers, technical founders, and small teams turn Anthropic models into reliable software—not demos that look good in a screenshot and fall apart under real input.
The central promise of this site is:
Build the smallest useful version, then test what breaks.
We publish reproducible tutorials, working code, clear test conditions, observed failure modes, cost notes, and production considerations. No hype. No unverified claims. No pretending a prototype is production-ready.
About the Author
Caleb Fletcher
Independent AI developer and technical educator based in Boise, Idaho.
I’m 32. I started as a backend developer building SaaS systems with Python, TypeScript, and PostgreSQL—APIs, databases, authentication, and asynchronous jobs. Over time my work shifted toward production-oriented LLM applications, especially Anthropic’s API surface: agents, tool use, structured outputs, workflow automation, and deployment.
Today I combine independent AI development, limited technical consulting for startups and small teams, and writing this site. I am not an Anthropic employee, insider, or affiliate. I do not claim special access, confidential information, or client results that cannot be reproduced from public documentation and careful testing.
What I try to do instead is straightforward:
Show the implementation before making broad claims
Explain why a design choice was made, not only which code to copy
State model versions, dependencies, costs, failure cases, and security trade-offs
Keep a short test plan before writing production code
Record the experiments that were too expensive, unreliable, or difficult to maintain
Outside of work I hike the Boise foothills, read engineering papers and technical changelogs, and look for good independent coffee shops. I’m married and currently have no children.
What You’ll Find Here
The writing is organized around five practical areas:
Anthropic-5 Foundations — authentication, messages, context, model selection, reliable request design
Agents and Tool Use — bounded agent loops, human approval steps, tool design, preventing uncontrolled behavior
Production Workflows — document processing, triage systems, internal research assistants, queues and retries
Testing, Evaluation, and Debugging — small evaluation sets, structured-output validation, latency/cost/quality experiments, trace-based debugging
Deployment and Consultant Notes — secrets, observability, privacy, cost estimation, production readiness checklists, and realistic adoption decisions
Every substantial tutorial aims to include a tested environment, the minimal working path, the important design choices, the ways it can fail, production considerations, and a verification step you can run yourself.
Editorial Boundaries
All model names, API behavior, SDK syntax, pricing, and limits are checked against current official documentation before publication.
Fictional or illustrative examples are clearly labeled.
No fabricated benchmarks, customer outcomes, or test logs.
Privacy, secret management, prompt injection, data retention, and human review are treated as first-class engineering concerns.
The site does not claim Anthropic sponsorship, endorsement, or privileged access.
Contact
If you have a question about a tutorial, find an error, or want to discuss a practical Anthropic implementation problem, you can reach me through the site’s contact options.
Thanks for reading.
Let’s start with the smallest useful version.