Project 6 — LangGraph agent
Words made simple
A few useful meanings before you read the explanation.
- AI
- Software techniques for tasks such as recognizing patterns, understanding language or generating content.
- API
- A way for one piece of software to ask another for data or an action. A claims API might return the current status of a claim.
- Schema
- A description of the fields and value types that data should contain. It helps check that an answer has the expected shape.
More words from this lesson
- Deterministic
- Following steps or rules defined by code. The model does not decide which step should run next in a deterministic workflow.
- State
- The data describing where a workflow is now, what it already knows, and what still needs to happen.
- Checkpoint
- A saved snapshot of workflow progress that can help it continue later.
- Durable
- Able to retain progress and recover across interruptions. Durable workflows require appropriate storage and retry behavior.
- Idempotency
- Making a repeated request have the same intended business effect as one request. It helps avoid duplicate submissions or payments.
Requirements
Convert the assistant into an explicit state graph, add durable progress, clarification/approval pauses, and safe resume.
Architecture
Router node → read/search or draft nodes → review → validated continuation → response. State and transitions are inspectable.
Technologies
TypeScript LangGraph, compatible schemas, supported durable checkpointer, safe business services, stream event projection.
Database design
Run ownership/version, checkpoint reference, immutable draft, pending review event, and authenticated decision record.
API design
Start/status/resume routes; require ownership and current pending event on resume.
AI design
Model nodes handle intent and language; deterministic nodes handle permissions, validation, review routing, and budget enforcement.
Security
Server-controlled identity, restricted graph tools, exact draft approval, safe state streams, and idempotent effects.
Evaluation
Worker restart, concurrent thread requests, replay, duplicate resume, rejected approval, and versioned pending runs.
Observability
Node timings, state transitions, checkpoint errors, pause age, resumed outcomes, and linked traces.
Deployment
Durable store, deployment draining/migration plan, serialized per-thread writes, rollback compatible with pending state.
Interview questions
- “Why LangGraph?” Answer: explicit state, branching, and recovery.
- “What repeats after interrupt?” Answer: the interrupted node can restart, so isolate side effects and use idempotency.
Acceptance: A restarted worker resumes an authorized task without duplicate external effects.
Can you explain it without the notes?
Project 6 — LangGraph agent
Use your own words. Explain an example and one limitation before checking the explanation.
Check your explanation
Requirements: Convert the assistant into an explicit state graph, add durable progress, clarification/approval pauses, and safe resume.
Turn this concept into a clear answer.
Practice this conceptAdapted from 13_AI.MD · “Project 6 — LangGraph agent”. Examples are study fragments; framework behavior can depend on your version.