Principles of Building Agents
27 Jun 2026 - 27 Jun 2026
- book by Sam Bhagwat of Mastra
- focused on using LLMs, not building/training them.
- Pretty basic so I'm not getting a lot out of it. Some tricks and I need to be more hands-on with Mastra
Prompting
- zero, one, many shot
- seed crystal – ask LLM to generate prompt
Typically you should ask the same model that you’ll be prompting: Claude is best at generating prompts for Claude, gpt-4o for gpt-4o, etc.
- Is this true? Why?
Building an Agent
- Tool mindset
Hierarchical memory is a fancy way of saying to use recent messages along with relevant long-term memories
RAG tricks
- "Memory Processors" that cut down on context
- Dynamic Agenrs. dont quite see the point of this one.
- Guardrails, prompt injection
Cloud-based web search APIs. There are a few web search APIs that have become popular for LLMs to use, including Exa, Browserbase, and Tavily.
- and a bunch of others, prob many new ones since then
an “agentic iPaas” (integration-platform-as-a-service). we’ve seen folks be happy with Composio, Pipedream, and Apify.
Graph-based workflows
- Yes obvious good idea which I havent been thinking of for some reason. Maybe it conflicts with agent metaphor in my head?
- Mastra has a functional API for defining these, so that's yet another metaphor (but technically fine).
- unclear from the text if this builds some structure or executes something (prob the former)
- human-in-the-loop steps with suspend/resume (bad metaphor, I wouldnt' do it that way, a human and agent should be on equal ontological footing)
Streaming
- Something I've totally ignored, but realize you need it to have a framework. Should go in ellellem if it isn't there .
- Electric | Agents on sync ElectricSQL sounds interesting. It is mostly about the sync, "agents" is pure buzzseeking
Observability and Tracing
The standard format for traces is known as OpenTelemetry, or OTel for short.
- Wow had no idea that was a thing, good to know
RAG
- stuff I know<
- Mastra supports chunking pipeline which surprised me a bit
- Agentic RAG – with tools – not sure I get it
- ReAG – reasoning RAG
Multi-agent systems
- Man is that all it takes? I'm overthinking things.
- MA Patterns
- Agent Supervisor
- A2A protocol (should be more familar)
Evals
- So you just instantiate HallucinationMetric? How does that work?
Deployment / UI
- some standard AI-focused UI frameworks: Assistant UI, Copilot Kit, and Vercel’s AI SDK UI
- Deployment and scaling stuff that I admit I haven't thought about much so its a good overview
Multimedia
- ditto
Code generation
