Work
Production systems, case studies, public projects, and supporting systems. The index below is the complete guide to the work on this site. Operational walkthroughs use illustrative, anonymized data.
The operating system behind an ecommerce business
flagshipStorefront, marketplaces, pricing, purchasing, inventory, accounting, advertising, fulfillment, and AI evolved into one production platform - without stopping the business to rewrite it.
Letting the system set prices
flagshipHow the pricing pipeline actually works: what the agents are allowed to see, the rules they cannot break, and how the whole thing is tested before it is trusted with real prices.
Every dollar accounted for
flagshipAn append-only double-entry platform for marketplace settlements, FIFO inventory, international goods flows, Xero synchronization, and reconciliation.
What should we buy with the cash available today?
case studyInventory simulation and constrained budget allocation across velocity, stockout risk, lead time, freight mode, and expected return.
Advertising optimization with an independent brake pedal
case studyEmpirical scoring, structured exploration, desired-state synchronization, and intraday spend controls for live marketplace advertising.
Envoy: The terminal I wanted
public projectWhy I rolled my own web-first terminal emulator and hosted PWA for server-side development across devices, with voice and agent ergonomics.
AgentLib and Code Agent
publicThe agent framework and interactive coding agent behind the production agents - public on GitHub.
Frameworks: the same idea, twice
frameworksjpsql, a typed query builder born of frustration with ORMs and string-interpolated SQL, and AgentLib, built years later on the same object-based philosophy. With code.
Fifteen years on the revenue path
case studyA custom ecommerce storefront that kept serving the business while the channels, providers, and systems around it changed.
Law-firm scheduling, check-in & outreach
client workAn auditable scheduling/check-in system and an evidence-first client outreach pipeline built around how a law firm actually works.
Built for the warehouse floor
case studyIdempotent label purchases, document transformation, printing, tracking, and recovery across eight carrier integrations.
The breadth behind the case studies
Targeted services, operational tools, and developer utilities that support daily operations across the platform.
Report Archive
evidence before interpretation
A PostgreSQL archive for external marketplace and advertising reports: raw JSONB payloads in report-specific tables, event-time extraction, natural-key and occurrence-aware deduplication, ingestion logging. Research notes document where vendor identifiers collide or date semantics differ from their apparent meaning.
schema-flexible ingestion · empirical key validation · backfills · auditability
Glanceboard & Watchtower
make silent failure visible
An always-on office status board plus health check-ins for databases, disks, systemd units, journals, cron reports, and workflow freshness. Quiet when healthy; unmistakable when an operator needs to act.
observability · operational UX · agent-readable status
Browser Control
deterministic runs, agent-assisted repair
A browser automation platform with guarded session acquisition and AI-oriented page snapshots. An agent authors a workflow once; normal runs execute without an LLM; individual stages are repaired when a site changes.
Playwright · hybrid deterministic/AI · bounded generated code
Customer messages & email triage
AI only for ambiguity
Per-folder UID watermarks and deterministic routing for known senders; a narrowly constrained classifier handles ambiguous messages with safe fallback to human review. The surrounding system owns claims, SMTP delivery, and IMAP state repair.
IMAP/SMTP correctness · durable state · human fallback
RMA & returns
exceptions as first-class workflows
Returns and RMA state coordinated across providers with barcode normalization. The value is not the happy path - it is preserving identity and status when physical items, communications, refunds, and marketplace events diverge.
exception workflows · physical/digital reconciliation
Cash Flow
normalize unstable banking identities
Local financial control combining SimpleFIN and browser-automated bank data: canonical transaction identity where upstream IDs are regenerated, chunked backfill, outage recovery, balance snapshots, and payment planning.
financial data · deduplication · recovery
Recurring Sales
idempotent scheduled commerce
Recurring Stripe charges connected to customer/address deduplication, order creation, PDF receipts, email delivery, and daily/weekly/monthly/yearly scheduling.
payments · idempotency · document generation
Personal Executive Coach
durable longitudinal agent product
A private PostgreSQL-backed coaching system: ingestion, canonical conversation, durable worker claims, transactional outbox delivery, planning graphs, reminders, append-only provenance with correction and semantic rewind, bounded retrieval, XMPP transport, and proactive scheduling. Thoroughly tested with ~1,777 automated tests.
AI product architecture · durable workflows · test discipline
Envoy
portable terminal and agent interface
The terminal that runs my own development across devices. Native scroll buffer, multi-tab PTY lifecycle, mobile touch gestures, path hover with file and image thumbnail previews, drag-to-upload file insertion, per-session memory limits, and integrated voice/text agent control.
terminal protocols · real-time UI · mobile PWA · voice & agents
Gaia Voice Server
voice-to-terminal agent bridge
A thin Android client connects to a server-owned PTY/agent session and Gemini Live voice session, separating voice and agent lifecycles and bridging synchronous tool calls through controlled polling.
Android/Kotlin · real-time voice · lifecycle separation
LLM Compatibility Gateways
protocols, streaming, and auth
Codex, Cursor, and Workbuddy gateways adapt specialized backends to OpenAI-compatible interfaces: OAuth refresh, account pools, SSE reconstruction, model catalogs, usage/quota behavior, protobuf handling, session checkpoints. Public; unofficial.
protocol reverse engineering · streaming · compatibility layers
Adaptive Enhance
image processing in Rust
A dependency-light exposure-correction implementation supporting grayscale, RGB, palette, alpha, 8- and 16-bit inputs, with pipe-oriented PNG tools and library/CLI APIs. Public.
algorithms · image formats · Unix-tool composition
Pickcraft
resumable prospect intelligence
A browser-research pipeline for prospect discovery, evidence collection, deduplication, scoring, leases, retries, and ranked export.
research workflows · resumability · evidence-based scoring
Chain & warehouse tooling
purchasing to physical execution
Purchase orders, receiving, preparation/shipping, inventory removals, documents, labels, supplier management, and warehouse workflows connecting purchasing decisions to physical execution.
supply-chain operations · operator tooling
Questions about any of these?
Architecture details, operational volumes, and measured outcomes are tracked privately and available in conversation.
hello@jacobstoner.com