Commit-safe database MCP

Let MCP agents use Postgres and MySQL without giving the model SQL or write credentials.

Synapsor exposes reviewed business capabilities. Reads are tenant-scoped and evidenced. Writes become exact proposals and commit only through a trusted runner with approval, idempotency, and stale-row checks.

MCP connects the agent. Synapsor controls the commit.

Run the open-source demo See the guarded commit

Local-first · No account required · Source DB unchanged until approval · Postgres + MySQL

How it works

Agent writes become reviewable database-change proposals.

Step 1

Connect read-only

Select the Postgres/MySQL tables, views, fields, tenant key, and object key an agent may use.

Step 2

Agent proposes a change

The model calls an approved capability, not raw SQL or a writer connection.

Step 3

Inspect evidence and the row diff

Synapsor records source rows, policy evidence, query audit, and the exact proposed patch.

Step 4

Approve or reject

A reviewer or deterministic policy decides whether the proposal is approved for writeback.

Step 5

Trusted runner applies and reports

A customer-controlled runner validates guards, executes a parameterized one-row update, and returns applied/conflict/failed for replay.

See one proposal end to end

The source database stays unchanged while the change is reviewed.

The canonical late-fee support case shows the complete change-control loop: request, bound tenant/object context, evidence, row diff, approval, worker-ready job, writeback result, and replay.

External DB · Synapsor review branch

Run the demo Read write proposal docs

1Request

Can we waive the $55 late fee for Acme Robotics?

2Trusted scope

tenant_id=acme · current_ticket_id=T-1042 · principal=support_agent_17

3Evidence

customer tier, invoice, open ticket, late-fee policy

4Row diff

status: open -> pending_review; resolution_note: null -> approval note

5Decision

Awaiting support lead review

6Worker-ready job

Structured patch, tenant guard, primary key, expected updated_at, idempotency key

7Replay

Run, evidence, approval state, writeback result, and audit stay linked

MCP is the connection, not the commit boundary

Without Synapsor, the hard part lives in app glue.

Without Synapsor

Connect agent to database.
Give it a tool.
Hope it behaves.
Approval, idempotency, stale-row checks, and replay become app glue.
A normal tool call can become durable business state too quickly.

With Synapsor

MCP calls a reviewed semantic capability.
Synapsor binds trusted tenant, principal, and object context.
Reads become evidence and query audit.
Writes become exact proposals with before/after diffs.
A trusted runner commits only after approval and conflict checks.

Open source where trust matters

Inspect the code that applies the database update.

Synapsor Runner is the open-source trusted-writeback data plane. It runs in your environment, keeps the write credential there, accepts only approved structured jobs, generates parameterized SQL, enforces tenant and conflict guards, and reports the result to Synapsor.

Synapsor Cloud

proposal, evidence, approval, replay, job lease

Your environment

write credential, validation, transaction, result

Postgres/MySQL

existing source of truth

Start with one real workflow

Focus Synapsor on the first database change your agent should not make silently.

Support ticket updates

Propose status and resolution-note changes for a support lead to review.

Billing, fee, or refund adjustments

Stage late-fee waivers, credits, or refund notes for a billing owner or deterministic policy.

Order and account-state changes

Propose order status, account state, or review notes with primary-key and tenant guards.

The deeper platform is still there

Start beside your existing database; move native workflow state into Synapsor when it belongs there.

Start beside your existing database. When agent-owned workflow state belongs in Synapsor, Synapsor-native tables add real branch, settlement, and merge semantics.

Compare branching modes Synapsor-native quickstart

text

External Postgres/MySQL
  -> Synapsor review branch
  -> approved for trusted writeback

Synapsor-native tables
  -> real Synapsor branch
  -> deterministic settlement
  -> merge into Synapsor main