Synapsor-Runner: Instructions file for Codex

Agent Guide For Synapsor Runner

Synapsor Runner is an OSS MCP safety layer for Postgres/MySQL agents. It replaces raw database tools such as execute_sql with reviewed business capabilities, proposal-first writes, approval outside the model, guarded writeback, and local evidence/replay.

First Commands

Use the stable package for public/user-facing examples:

npx -y @synapsor/runner demo --quick
npx -y @synapsor/runner audit --example dangerous-db-mcp

Use the local checkout while editing this repo:

corepack pnpm install
./bin/synapsor-runner demo --quick --no-interactive
./scripts/verify-release-gate.sh

What Not To Change Casually

Do not weaken these safety boundaries without a failing test and an explicit design note:

• no model-facing execute_sql, raw SQL, approval, commit, apply, or writeback tools;
• trusted tenant/principal context must come from backend/session/env config, not model-controlled arguments;
• proposals must not mutate the source database before approval;
• direct writeback must enforce tenant, primary key, allowed columns, expected-version/conflict guard, affected-row count, idempotency, and receipt recording;
• app-owned handlers must re-check tenant/scope, expected version, idempotency, allowed business action, transaction/rollback, and safe error receipts;
• local store lease guards and stale-lease reclaim must keep concurrent writers from corrupting the SQLite store.

How The Flow Works

MCP tool call
-> trusted context
-> scoped read from Postgres/MySQL
-> evidence/query audit
-> proposal diff
-> approval outside MCP
-> direct writeback or app-owned executor
-> receipt/replay

The source database remains the source of truth. Runner stores local evidence, proposals, receipts, query audit, and replay in SQLite.

Add A Capability Without Reading dist/

Start from schema inspection or a recipe, then run the smoke boundary before wiring an MCP client:

export DATABASE_URL="postgres://readonly:...@localhost:5432/app"
./bin/synapsor-runner onboard db \
  --from-env DATABASE_URL \
  --engine postgres \
  --schema public \
  --table invoices \
  --primary-key id \
  --tenant-column tenant_id \
  --conflict-column updated_at \
  --mode review \
  --visible-columns id,tenant_id,status,late_fee_cents,updated_at \
  --namespace billing \
  --object-name invoice \
  --id-arg invoice_id \
  --patch late_fee_cents=fixed:0 \
  --write-url-env SYNAPSOR_DATABASE_WRITE_URL \
  --yes \
  --output synapsor.runner.json

./bin/synapsor-runner config validate --config ./synapsor.runner.json
./bin/synapsor-runner tools preview --config ./synapsor.runner.json --store ./.synapsor/local.db
./bin/synapsor-runner smoke call --config ./synapsor.runner.json --store ./.synapsor/local.db