From the field.
What Jigar learns building and training, shared as posts. Specifics over slogans.
The maker is not the verifier: how I build self-improving agent loops without pretending models self-learn
Most teams prompt harder, get a better answer, and start over tomorrow. That is not compounding. Self-learning updates model weights from experience; no public model including Fable 5 does that today. Self-improving means the system gets better: run, log, distill, repeat. The golden rule is maker ≠ verifier. Here is the four-layer architecture and loop patterns I ship.
Claude Cowork is not Claude Code for civilians: the knowledge-worker playbook after the mobile launch
Anthropic shipped Claude Cowork on mobile and web July 8, starting with Max subscribers. Usage data from 1.2 million sessions shows more than 90% of Cowork work is non-technical: memos, RFP reviews, inbox triage, decks. Tasks run in the cloud, sync across devices, and continue when you close the app. Here is how I govern Cowork without treating it like a coding agent.
How to actually use Fable 5: the four-layer architecture behind Mythos-tier results
Fable 5 is back globally, but most teams use it like a bigger Sonnet: prompt harder, better answer, start over tomorrow. Mythos-tier models need Mythos-tier systems: primitives, orchestration, memory, and self-improvement. The golden rule is maker ≠ verifier. Here is the architecture I draw on every engagement after the July 7 billing cliff.
MCP stateless headers can leak secrets into every proxy log: the security checklist I run 22 days before July 28
The 2026-07-28 MCP spec drops sticky sessions and routes on Mcp-Method and Mcp-Name headers. That is a scaling win and a new exfiltration surface. Akamai and SecurityWeek flagged desync risk and accidental API-key mapping into headers visible to load balancers. Here is the pre-GA security checklist I run on gateways and remote servers.
Claude Sonnet 5 is the new default: the migration checklist I run before swapping claude-sonnet-4-6 in production
Anthropic shipped Sonnet 5 on June 30 as default on Free and Pro chat and as claude-sonnet-5 on the Platform API at $2/$10 per million through August 31. Three breaking changes matter for agent builders: adaptive thinking on by default, manual extended thinking removed, and non-default sampling parameters return 400. The tokenizer adds roughly 30% tokens for the same text. Here is the swap checklist.
Fable 5 is back globally: the redeployment routing checklist I run before July 7
Anthropic restored Claude Fable 5 worldwide on July 1 after US export controls lifted June 30. Pro through Enterprise plans get up to 50% of weekly usage limits included through July 7, then usage credits. A new safety classifier blocks the Amazon-reported jailbreak in 99%+ of cases. Here is how I re-promote Fable without repeating June's config chaos.
Codex Record and Replay turns one demo into a Computer Use skill: how I inspect generated skills before trusting them unattended
Codex app 26.616 adds Record and Replay on macOS: perform a workflow once, Codex packages it into a skill you replay with different inputs. Thread handoff and automation run history ship alongside. Computer Use must be enabled. Here is the review checklist I run before any recorded skill runs unattended.
One agent spend dashboard for Cursor, Claude Code, and Copilot: what Copilot's ai_credits_used field unlocks
GitHub added ai_credits_used to the Copilot usage metrics API on June 19. It is a per-user total, not yet split by feature or model, but it closes a gap I have been papering over with spreadsheets. Here is how I unify Copilot credits with Claude API keys and Cursor team usage into one attributable spend view.
MCP goes stateless on July 28: the four-week migration checklist I run before deleting sticky sessions
The 2026 MCP release candidate locked May 21. The final spec lands July 28 with a stateless core: no initialize handshake, no Mcp-Session-Id, routing on Mcp-Method and Mcp-Name headers. Here is the pre-GA checklist I run on remote servers, gateways, and clients so production does not learn about the change from a 502.