Cartpanda · Agent Harness
Control plane preview · v0.1
claude-opus-4-7 onlinePlano, TX · Delaware · main@sha:a1b2c

Honest scope note. This harness preview runs on Vercel with the Claude API so you can click through it in 60 seconds. In your stack it becomes a Hono service in front of your agent runners, wired into your Neon + Drizzle + Temporal Cloud + ECS Fargate pipeline. TypeScript end-to-end. No Python, no n8n, no glue-layer.

For Renato · Cartpanda & Fluveo

Constrain.
Track.
Synthesize.
Merge.

A four-module preview of the control plane your agents need before a single line of generated TypeScript touches a charge in your Hyperswitch connector. Deterministic AST-level guardrails on monetary code, live PROGRESS.md synchronisation across git worktrees, Temporal saga synthesis from a one-liner spec, and a human-in-the-loop merge queue that holds the pager until a senior clicks Approve. No LLM math, no parseFloat on cents, no empty catch.

01 FinTech AST guardrail02 PROGRESS.md state tracker03 Temporal saga architect04 HITL merge queue
01

FinTech AST Guardrail

Every PR authored by an agent passes through a deterministic pre-commit gate before it ships into your Hono handlers. parseFloat on monetary values, empty catch blocks, missing Zod parse at the boundary — the gate catches them all and replies with the corrected code. The LLM is a pair, not a cowboy.

Business value · Zero parseFloat on a charge. Ever.

agent_output.ts · pending reviewbranch: agent/hyperswitch-charge
17 lines · TypeScript · ESM
guardrail · agent.trace
// hit Run Pre-Commit Gate to validate the snippet
02

PROGRESS.md State Tracker

Each agent writes to its own worktree and commits progress to a shared PROGRESS.md. The orchestrator tails it live and coordinates merge readiness. No shared mutable state, no Slack pings, no cross-agent contention. Just file-based source of truth — the same pattern your team already uses, instrumented.

Business value · See four agents converge in real time. Exactly your internal workflow.

orchestrator · agent.trace
// click Start feature to drive the orchestrator
PROGRESS.md0 / 9 tasks
# Feature: Add 3DS refund flow (spec v1)
> orchestrator: claude-opus-4-7
> worktrees: 4 parallel
## agent_db
branch: feat/3ds-refund-db
[ ]Drizzle migration for refunds.three_d_secure_token
[ ]Down migration + rollback test
[ ]Update charges.ts schema with typed reference
## agent_api
branch: feat/3ds-refund-api
[ ]POST /v1/refunds/3ds handler with Valibot guard
[ ]Wire idempotency middleware (IDM-004)
## agent_test
branch: feat/3ds-refund-test
[ ]Vitest integration suite: happy path + timeout retry
[ ]Mock Hyperswitch 3DS callback
## agent_saga
branch: feat/3ds-refund-saga
[ ]Temporal workflow with compensation on timeout
[ ]Activity timeouts per ADR-008
03

Temporal Saga Architect

One-line spec in, typed Temporal.io workflow out: proper activity timeouts, compensation on every side-effect, typed input / output. The diagram is generated from the same response so the Lead Architect can audit the saga shape before the agent writes a single line of production code.

Business value · From one sentence to a reviewable saga. Seconds, not an afternoon.

saga.spec
claude-opus-4-7 · max 2500 tokens
// submit a saga spec to see the workflow + diagram.
04

Human-in-the-Loop Merge Queue

Every PR authored by an agent lands here with the guardrail matrix attached. A senior reviews the diff, the LLM reasoning note, the activity timeouts — and clicks Approve. No merges without a human signature. Blocked PRs are automatically re-prompted with the failing rule.

Business value · Your pager stays quiet. Your SOC-2 auditor stays happy.

agent_harness.merge_queue4 awaiting a human
cartpanda/payments · main
idtitleagentdiffconfstatus
PR-412Add idempotency key to Hyperswitch connectorclaude-code+62 -1175%needs review
PR-411Temporal saga: webhook replay handler for Stripecodex+88 -491%needs review
PR-410Refund saga for Brazilian Pix network timeoutscursor+104 -2263%blocked
PR-409Drizzle schema migration: add refund_reason to chargesdevin+28 -196%approved
PR-408Add Valibot guard on /v1/charges POST endpointclaude-code+34 -888%needs review