Ujex Blog

Posts on every layer of agent infrastructure.

Open Source AI Agent SDK Comparison 2026: LangGraph, Letta, Mastra, Agno, Pydantic AI, Ujex
Six open-source agent SDKs compared by what they actually do. Frameworks vs runtimes vs substrates. With code samples and a clear pick-by-use-case guide.
Apr 12, 2026
How to Give an AI Agent an Email Address (2026 Guide)
How to give your AI agent its own real email inbox — with or without a SaaS vendor. Six approaches compared (AgentMail, Nylas, Mailgun, self-hosted Postfix, Composio, Ujex Postbox) with code samples and cost.
Apr 05, 2026
Self-Hosting Postfix + OpenDKIM + Brevo for AI Agent Email
The runbook. Hetzner VM, Postfix on :25 (when port-25 unblocks), OpenDKIM signing, Brevo as the relay until you don't need it. End-to-end DKIM/SPF/DMARC. ~4 hours, $5/month.
Mar 19, 2026
Building With LangGraph On Top Of Ujex (Reference Architecture)
LangGraph for the orchestration. Ujex for the substrate (email, memory, ingress, audit, mobile). Concrete reference architecture with code, deploy commands, and where each piece runs.
Feb 24, 2026
Best Email APIs for AI Agents in 2026 (Honest Comparison)
Six email APIs, ranked by use case. AgentMail, Nylas, Composio, Mailgun, self-host, Ujex Postbox. With actual costs at 1k / 10k / 100k messages/month.
Feb 12, 2026
Git-Backed Memory for AI Agents: Why Markdown Beats Vector Stores
Your agent's memory should live in git, not a database. Here's the case for markdown-first, bucket-as-source-of-truth memory — version control, grep, diff, no vendor lock-in.
Jan 30, 2026
Mem0 vs Letta vs Zep vs Ujex Recall: Picking an Agent Memory Layer
Four agent memory products. One isn't an agent framework. One is a managed graph memory. One is markdown-first and lives in your bucket. Honest matrix + when each is right.
Jan 25, 2026
Human-in-the-Loop AI Agents: A Production Setup Guide
Adding approval gates to autonomous AI agents. Mobile-first design, sub-second latency, biometric auth. Code, architecture, and the design decisions that matter at scale.
Nov 26, 2025
LangGraph + Ujex Recall: Long-Term Memory Without Building Your Own
Drop Ujex Recall into a LangGraph agent loop. Markdown-first memory in your bucket; BM25 + vectors. Survives across sessions, persists across deployments, greppable on your laptop.
Oct 22, 2025
Self-Hosted vs SaaS Agent Infrastructure: When Each Makes Sense
Self-hosted AI agent stack vs cloud provider comparison. Data residency, compliance risks, vendor lock-in, ops cost. When self-host wins; when cloud wins; when hybrid is right.
Sep 30, 2025
A Hash-Chained Audit Log for Your AI Agent (And Why It Matters)
When your agent does something weird, can you say what it did? Append-only, hash-chained logs are the difference between investigation and guesswork. Code, structure, and a 200-line library.
Sep 03, 2025
Migrating From Mem0 / Letta / Zep to Ujex Recall
Export, transform, re-ingest. Plus the things to think about: embedding model differences, namespace mapping, and what to do with frontmatter.
Aug 31, 2025
AgentMail Alternatives: 5 I Actually Tested
I built test agents on five AgentMail alternatives: Nylas, Mailgun + custom, Composio, self-host Postfix + Brevo, Ujex Postbox. Here's what each is good at and where each falls down.
Aug 22, 2025
Stopping a $5,000 Surprise Bill From An AI Agent
How to stop your AI agent from running up a huge API bill automatically. Per-agent spending limits with real-time alerts. Open-source governor for AI agent cost management.
Jul 14, 2025
Cloudflare Tunnel vs ngrok vs Ujex Ingress
Three reverse-tunneling stacks. Different sweet spots. Cloudflare Tunnel for free + custom domain. ngrok for fast prototyping. Ujex Ingress for agent-shaped workloads.
Jun 19, 2025
Eight Vendors Or One: The Real Cost of Glue Infrastructure
An opinion piece. Most agent teams are running SendGrid + ngrok + Pinecone + Temporal + Auth0 + Twilio + Stripe + Honeycomb. Eight vendors, eight integrations, eight failure modes.
May 22, 2025
MCP Server for Email: Adding Postbox to Claude Desktop
Wire Ujex Postbox into Claude Desktop / Cursor / Cline / Zed via the @ujex/postbox-mcp server. Five minutes; agent gets full inbox/outbox tools.
May 19, 2025
AI Agent Audit Logs for HIPAA, SOC 2, and GDPR Compliance
What auditors actually need from your agent audit trail. Hash chains, retention, PII handling, and the gap between 'we have logs' and 'we have an audit log that passes review.'
May 10, 2025
Phone Approvals For An AI Agent: How `mobile.ask` Works
Human-in-the-loop AI agent setup using mobile push. Approve before send workflow for autonomous agents — sub-second mobile oversight, biometric confirm, FCM-backed. The mobile.ask primitive in detail.
Apr 30, 2025
How to Receive a Webhook on a Local AI Agent (7 Ways, Honest)
Your agent runs on your laptop. OpenAI / Stripe / GitHub / your own service needs to call it. Here are seven ways, with code samples and tradeoffs for each.
Apr 22, 2025
What Even Is 'Agent Infrastructure'? A Field Guide for 2026
Agent frameworks, agent runtimes, agent infra, agent observability, agent evals, agent memory layers — the words overlap. This is a definition pass with examples in each box.
Apr 19, 2025
Why We Built Postbox When AgentMail Exists
Honest founder post. AgentMail is a great product. Here's why we built Postbox anyway — and why it makes sense to have both options in the world.
Mar 15, 2025