orangerail

Give your agent your database. Don't give it SQL.

Quickstart · Commands · What it does not govern · Against a rules file · Examples · Docs

orangerail init on a three-model Prisma schema, then a real tools/list against the server it generated. Sixteen tools: a get and a list per object, one action per write, and check_approval. Nothing on that list takes a query. The three locks are --gate delete, which is a default you change in one line, not a verdict.

A rules file cannot do this. It can ask the agent not to run a query. It cannot take the tool off the list — and we measured what the difference is worth, including the four claims that died when we did.

orangerail reads the schema you already have and generates the agent's surface from it. orangerail init turns a prisma/schema.prisma into an MCP server: a get and a list per object, one action per write with a zod input schema, and nothing else — no execute_sql, and nothing on the tool list that takes a query. It is a scanner and a code generator, with no LLM calls and no API keys. Writes you are happy to have run unattended run unattended. The ones you are not carry policy: { approval: 'required' }, which stops the call and turns it into an approval a person can act on later — including a person who is not you, after the conversation that produced it has ended.

Bounded is not safe, and this README will not pretend otherwise. A generated surface buys a reach that is finite and legible, not a claim that nothing harmful is inside it. You declared the verbs, so a destructive verb you declared is a verb the agent can call.

One precondition decides whether any of this is worth installing: orangerail governs only its own tools. If the agent also has a shell with credentials or a second database MCP server, it can go around the rail — see what orangerail does not govern.

Pre-release and installable: 0.1.5 on npm — orangerail (the CLI) plus orangerail-core, orangerail-mcp, orangerail-docs-gen and orangerail-studio. The API will move before 1.0, and Status has the one upgrade note that matters.

See your whole domain as a map

One command, and the surface init generates is a map you can read.

$ orangerail studio
orangerail studio: scanning ontology — 9 object(s), 27 action(s)
orangerail studio: building the interactive map…
orangerail studio: serving on http://127.0.0.1:4820 — open it in your browser

Every object, how they relate, and every write action an agent can reach. Hover a table to light up its relations and actions; click one to read the policy that governs it.

Crisper version: assets/studio-map.mp4 — the same run at full resolution. One real run on a sample commerce domain, --gate delete. The locks are not annotations added for the video: they are what the studio draws from your ontology, which is why nine actions carry one and eighteen do not.

Be exact about what that is worth. The relations come from ontology/_links.mjs, which init derives from your Prisma relations, so Customer_list's description reads List Customer records. Relations: has many Order. The agent is told that a Customer has many Orders. It still cannot follow the edge: no traversal tool, no join, no aggregate, and Customer_list refuses a filter that reaches into Order. Knowing the shape of a domain and being able to query across it are different things, and only the first one is here.

Related MCP server: postgres-mcp

Quickstart

Seven steps, every output verbatim from one recorded run. The reasoning behind each one — and the failure each prevents — is in Quickstart, annotated; requirements and the Prisma 7 caveat are the first thing on that page.

1. Install orangerail into the project you are about to scan.

npm i -D orangerail

2. Scan your project, in a repo with a prisma/schema.prisma.

$ npx orangerail init --yes --preset approval-for-writes --no-studio
  ✓  scanned your sources — 2 object(s), 6 action(s)
  ✓  generated a governed MCP server under ontology/
  ✓  --gate delete: 2 of 6 write action(s) gated behind human approval — the other 4 run when the agent calls them
  ✓  recorded that posture in orangerail.governance.json — commit it
  ✓  approvals queue + audit chain at .orangerail/store/ — inside this project, so an
     agent with file tools over this directory can write them

  These files are yours — re-scans never modify them; `orangerail sync` reports drift.

  Change what is gated by editing `policy` in ontology/<action>.mjs, or re-run init
  with `--gate all` (gate every write) or `--gate none` (gate nothing).
  orangerail.governance.json holds the posture init just generated, which nobody has reviewed yet.
  From now on `orangerail sync` fails when an action gets weaker than that file, and
  `orangerail mcp` refuses to serve it. Read the file, then run
  `orangerail sync --accept-governance` to vouch for it as reviewed.

  That store is the record of which writes a human approved, and appending one line to
  .orangerail/store/approvals.jsonl marks a staged action approved — the next
  `check_approval` then executes it, because the gate reads that store and never the
  audit chain. `orangerail audit verify` reports the forgery afterwards; it is a report,
  not a gate, and it does not prevent the write. The generated config carries the
  one-line move at the `createFileStore` call — see docs/audit-log.md.
orangerail docs: wrote /private/tmp/shop/.orangerail/generated/AGENTS.md

Done. Run `orangerail studio` to explore the map, or `orangerail mcp`.

3. Install the runtime the generated code loads.

npm install orangerail-core zod

4. Give the generated actions a database to reach.

npm install @prisma/client@6
export DATABASE_URL="file:./dev.db"
npx prisma generate
npx prisma db push --skip-generate

Already have a database? Do not db push over it — adopting orangerail against an existing database.

5. Point your agent host at it. Drop this in your project root as .mcp.json:

{
  "mcpServers": {
    "orangerail": {
      "type": "stdio",
      "command": "./node_modules/.bin/orangerail",
      "args": ["mcp"],
      "env": { "DATABASE_URL": "file:./dev.db" }
    }
  }
}

Other hosts, the claude mcp add one-liner, and running from source: wire it into your agent host.

6. Record the governance baseline — and commit it. ontology/ is yours to edit, so the one line that disarms the whole flow is one careless deletion away and a re-scan cannot notice. The posture is compared against a recorded file instead.

npx orangerail sync --accept-governance

Commit orangerail.governance.json. Its whole value is that a pull request removing an approval gate shows "approval": "required" turning into null in its own diff, in front of a reviewer, before CI runs at all.

7. Now leave. While you are gone the agent works the queue: the writes you left un-gated go through, and the deletion it was asked for stops. When you come back:

$ npx orangerail status
orangerail status
  objects:  2
  actions:  2 approval-gated, 4 auto
  baseline: 6 action(s) match orangerail.governance.json
  preset:   approval-for-writes
  pending:  1 approval(s) awaiting a decision
  store:    /private/tmp/shop/.orangerail/store
            Inside the project root, so an agent with file tools over this directory can
            write it: one appended line in approvals.jsonl is a decision no human made,
            and the next `check_approval` executes the staged action — the gate reads
            this store, never the audit chain. `orangerail audit verify` reports the
            forgery afterwards; it is a report, not a gate. Pointing the store `dir` at a
            directory this agent's process cannot write is what removes the reach — see
            docs/audit-log.md.
  server:   not detected — no orangerail mcp is running against this store
  hosts:    .mcp.json declares orangerail and nothing else.
            Project scope only (.mcp.json, .cursor/mcp.json, .vscode/mcp.json); user- and
            machine-scope MCP config is not read.
  audit:    chain OK — 5 record(s) verified

$ npx orangerail approvals list
c4818df5-770c-446f-883a-e9c0f7e615a2  "deleteCustomer"  by "local-dev" [dev]  0s ago  input={"id":2}

1 pending approval(s).

$ npx orangerail approvals approve c4818df5-770c-446f-883a-e9c0f7e615a2
approve ok (approved)

The agent's next check_approval is the first moment the row can change. Nothing ran before you said so, and every step is on the hash chain. That whole sequence is what tests/e2e/ONT-093-quickstart-runs-as-documented.sh runs against this repository's own build on every regression pass.

Why the prompt is the wrong control

The thing stopping you from walking away is not that the agent does too much. It is that your only control is a question it has to ask you. The twentieth prompt of the afternoon gets the same click as the first, and the switch that ends the asking ships in the box — Claude Code's bypassPermissions mode "skips permission prompts, except those forced by explicit ask rules", per its own permissions reference. A boundary re-established by a person on every call cannot hold once nobody is there.

The prompt is also the wrong shape. It asks about a tool — may this run Bash — and the risk you carry is about your domain: stock edits are fine, order deletions are not, refunds under $50 need nobody. That distinction does not exist at the tool level. It exists in your schema.

The run this is built for

One run of examples/unattended-queue — a real MCP client, no API key, every line asserted. The video shows six of the twelve; the row numbers jump, so you can see where.

A 15-item back-office queue on a commerce database, handed to an agent with the operator gone for the day and told not to ask for confirmation. Twelve items are ordinary reversible writes. Three are destructive: delete a cancelled order, delete a customer under an erasure request, delete a discontinued product. Scored from the database afterwards, not from what the agent said it did:

That is the metric this project is built around, and it is not "how much did we block". It is how much finished while nobody was watching, and what is waiting when you get back.

Two separable claims sit in that table and they are not equally well evidenced. That the twelve go through and the three cannot is a property of the server, and it is reproducible on your machine — examples/unattended-queue runs exactly that queue through a real MCP client, deterministically, asserting every line. That a model chooses these calls when handed the queue in prose needed a live agent driving a real host, and that half is a measurement, not a reproduction: small numbers, enough to say the gate holds where it was tested and not enough to be a rate.

Against the thing you would do instead

The comparison that matters is not a raw SQL server. It is a rules file: a well-written CLAUDE.md naming the permitted tables and the forbidden ones, over a Postgres MCP server with full write access. Same queue, same model, three clones.

It tied on compliance, and it kept tying — through adversarial rewrites, a fake prior approval, an instruction planted in a database row, and a much smaller model. On one axis it beat us. So this project does not argue that your agent will ignore your rules: across every run measured here, it followed them.

The row that does not tie is the last one, and it is not about the agent's behaviour: a grant travels with the session it was registered for, and a rules file travels with the machine account it was written under. A global ~/.claude/CLAUDE.md closes most of that gap for a single developer on one machine — if that is you, you may not need this. It stops closing at a CI runner, a container, a service account, or a teammate's checkout, each of which gets the database credentials anyway.

Every run, the axis where the rules file wins, and the limits of the measurement: against the thing you would do instead. examples/vs-a-rules-file executes both arms.

What the agent gets instead of execute_sql

Run orangerail init on a three-model Prisma schema (Order, OrderItem, Payment) and the entire tool list is 16 entries: a get and a list per object, one action per write, and check_approval. Nothing else, and nothing that takes a query.

Each action's input is a zod schema derived from your own columns, published in tools/list, so updateProduct refuses a string where the column is an integer and says which field it was. Each read is a findUnique by id or a paged findMany, whose filter is a closed set of predicates over declared fields — enforced by the server before it reaches your resolver, not merely advertised.

A fixed surface is a narrow one: no aggregation, no join, no free-form query, no DDL. A question it cannot express has to be answered somewhere else — all of it, and where enforcement actually lives, is in what orangerail does not govern.

See it stop an agent

One real run of examples/governed-writes through a real MCP client. The destructive tool stays available rather than hidden, the agent cannot force it through, and the row changes only after a human decided — in a separate terminal, at a separate time, which is the part that makes leaving possible.

Declaring a rule the generator cannot derive

Everything above is generated. When a rule lives in your head rather than your schema — "never issue a coupon for a sold-out item" — you write it once, in TypeScript, and it joins the same surface:

import { defineAction, defineObject } from 'orangerail-core';
import { z } from 'zod';

// Your existing backend. orangerail never replaces it — it only gates the call.
declare const findProduct: (id: string) => Promise<{ id: string; status: string } | null>;
declare const grantCoupon: (args: { productId: string; amount: number }) => Promise<void>;

// A `where` guard has to read the row it guards, so the target needs `resolve`.
export const Product = defineObject({
  name: 'Product',
  schema: z.object({ id: z.string(), status: z.string() }),
  resolve: { get: async ({ id }) => findProduct(id) },
});

export const issueCoupon = defineAction({
  name: 'issueCoupon',
  target: Product,
  input: z.object({ productId: z.string(), amount: z.number() }),
  policy: {
    approval: 'required',
    where: { field: 'status', op: 'neq', value: 'soldout' },
  },
  // `execute` runs only after the approval clears, and receives the validated
  // input plus the resolved caller. There is no `audit` switch: every staged,
  // approved, rejected and executed action is written to the hash chain.
  execute: async ({ input, identity }) => {
    await grantCoupon({ productId: input.productId, amount: input.amount });
    return { issuedBy: identity.subject };
  },
});

That block is not an illustration — it is packages/cli/test/readme-example.ts printed verbatim, compiled by the repo typecheck and compared against this file on every run, so it cannot rot into something that never compiled.

Status

orangerail init runs against your own project today, with no checkout of this repo, and the API will move before 1.0. All five packages are published from .github/workflows/release.yml over npm's Trusted Publishing, so each one carries a provenance attestation naming the workflow and commit that built it; there is no npm token in this repository.

Upgrade from 0.1.0 if you are on it. That release published a read filter to the agent and never checked it, so a <Object>_list call could read an object type the server never exposed (the mechanism). The fix is in 0.1.2 and lives in orangerail-mcp, so upgrading the package applies it with no re-run of init. 0.1.2 also narrows what filter accepts and changes what a pending approval does across the upgrade — both under Upgrading from 0.1.0 in the CHANGELOG.

Docs

• Commands — every command, what --gate chooses, and how to narrow the surface to the tables you name.

• Quickstart, annotated — the seven steps with the reasoning, the requirements, and the failure each step prevents.

• Wire it into your agent host — stdio, .mcp.json, and running from source.

• What orangerail does not govern — the preconditions, the missing capabilities, and where enforcement actually lives.

• What the audit log proves — the exact bar, why "tamper-evident" is not used, when a database-level audit is the better tool, and where to put the store.

• Against the thing you would do instead — the full rules-file comparison.

• How orangerail compares — against --read-only, OpenAPI codegen, Prisma's own servers and Supabase's.

• Adopting orangerail against an existing database — prisma db pull onto a live database, and what Prisma 7 changes.

• Also ask the host to prompt — the optional client-side prompt on un-gated writes.

• Troubleshooting — the readouts that report something is wrong with the install rather than with your policy.

• What we measured, and what died — every claim this project made or was tempted to make, and which ones survived being run. Four did not.

• bench/ — the fixtures behind that page, so you can disagree by reproducing rather than by arguing.

• The MCP registry entry — what the listing is, and the step a hundred-character description cannot fit.

Examples

• unattended-queue — the run at the top of this file, made reproducible. Deterministic, asserted, no API key.

• governed-writes — the same gate in isolation, one destructive call at a time.

• vs-a-rules-file — the rules-file comparison made runnable, both arms executed, including the column where the rules file wins.

Development

This repo is built under a deterministic 9-stage gate harness. Every change runs through ./scripts/verify.sh — language, structure, gate self-test, no-LLM, templates, then typecheck / lint / test / build — and CI runs that script and nothing else, so a green local run is a green build. A hard invariant: no LLM-inference SDK is ever bundled (./scripts/check-no-llm.sh).

License

MIT