https://richchris.com/blog/digital-self-meter https://richchris.com/blog/digital-self-meter A free, client-side tool that rates how real, active, and consistent your digital identity is — no signup, no data leaves your browser. Mon, 22 Oct 2026 00:00:00 +0000 https://richchris.com/blog/ Production notes on AI agents, DeFi safety, and hardening your systems. en-us Mon, 19 Oct 2026 09:52:35 +0000 https://richchris.com/blog/crypto-self-custody-basics https://richchris.com/blog/crypto-self-custody-basics Self-custody in 2026: hot vs cold wallets, what a seed phrase protects, and where a hardware wallet stops paying for itself. Mon, 19 Oct 2026 00:00:00 +0000 https://richchris.com/blog/agent-tool-calling-json-schemas https://richchris.com/blog/agent-tool-calling-json-schemas A tool definition is three things: a JSON Schema for inputs, a validation boundary, and a dispatcher. All three in runnable Python. Mon, 12 Oct 2026 00:00:00 +0000 https://richchris.com/blog/verify-smart-contracts-etherscan https://richchris.com/blog/verify-smart-contracts-etherscan Every on-chain transaction is public — if you know how to read it. Decode a transaction on Etherscan and run the five-step check before you interact. Thu, 02 Jul 2026 00:00:00 +0000 https://richchris.com/blog/harden-ssh-ubuntu https://richchris.com/blog/harden-ssh-ubuntu A default SSH install accepts passwords — and the internet never stops guessing. Three moves make it near-impenetrable: Ed25519 keys, sshd_config, fail2ban. Thu, 02 Jul 2026 00:00:00 +0000 https://richchris.com/blog/ai-agent-memory-python https://richchris.com/blog/ai-agent-memory-python Your agent forgets everything when the program exits. Here's the memory ladder: in-context history, a JSON file that persists, and a save_memory tool. Thu, 02 Jul 2026 00:00:00 +0000 https://richchris.com/blog/ai-agent-loop-python https://richchris.com/blog/ai-agent-loop-python Every AI agent — including the coding agents you use daily — runs the same four-step loop. Here it is in 40 lines of runnable Python. Wed, 01 Jul 2026 00:00:00 +0000 https://richchris.com/blog/avoid-defi-wallet-drains https://richchris.com/blog/avoid-defi-wallet-drains Phishing, malicious approvals, seed theft, rug pulls, fake airdrops — the five attacks that drain DeFi wallets, and the checklist that blocks them. Wed, 01 Jul 2026 00:00:00 +0000 https://richchris.com/blog/dns-over-tls-ubuntu https://richchris.com/blog/dns-over-tls-ubuntu Your DNS queries travel in plain text — readable by your ISP and anyone on the network. Encrypt them with DNS-over-TLS on Ubuntu in five minutes. Wed, 01 Jul 2026 00:00:00 +0000