# graphile-function-bindings
PostGraphile v5 plugin that exposes API-bound compute functions as typed
GraphQL mutations.
At schema build (gather phase), the plugin queries `function_api_bindings`
joined to `function_definitions` for the configured `apiId` and emits one
mutation per graphql-enabled binding:
```graphql
(input: Input!): Payload
```
The payload returns the created invocation (`invocationId`, `status`, and the
full `FunctionInvocation` when the table is exposed in the schema).
## Binding config
One binding serves both REST and GraphQL. Per-protocol behavior lives in the
binding's `config` jsonb:
```json
{
"graphql": true,
"rest": { "path": "/resize", "methods": ["POST"] }
}
```
- Absent `graphql` key ⇒ the mutation is enabled.
- `"graphql": false` ⇒ the binding is not exposed as a GraphQL mutation.
## Input type derivation
Derivation lives in `src/derive.ts` (protocol-agnostic — intended to be the
shared source for future REST payload validation). Priority:
1. A JSON Schema on the binding config (`config.schema` /
`config.payloadSchema`): object properties become input fields
(string/number/boolean/enum/array/required mapped to GraphQL equivalents).
2. The definition's `payload_args` (`[{ "name": ..., "type": ... }]`): each
declared arg becomes a nullable scalar field.
3. Fallback: a single `payload: JSON` field passed through verbatim.
No runtime payload validation is performed — derivation shapes the input
types only.
## Resolver
Invoking a function is a plain, RLS-enforced `INSERT INTO
function_invocations` executed on the normal authenticated connection
(`withPgClient` + `pgSettings` from the Grafast context). The server layer is
responsible for pgSettings (including the `jwt.claims.api_id` provenance
claim) — the plugin never sets claims, never uses a privileged connection,
and never bypasses RLS.
## Usage
```ts
import { createFunctionBindingsPlugin } from 'graphile-function-bindings';
const preset = {
// ...
plugins: [createFunctionBindingsPlugin({ apiId })],
};
```
The GraphQL server (`graphql/server`) wires this automatically per API using
the resolved `api.apiId`.
## Schema invalidation
Bindings are loaded once per schema build. New or changed bindings appear
after the next schema rebuild — i.e. when the server's cached PostGraphile
handler for the API is invalidated (graphile-cache LISTEN/NOTIFY) or the
server restarts. TODO: emit a cache invalidation NOTIFY when
`function_api_bindings` rows change so rebuilds happen automatically.
---
## Education and Tutorials
1. 🚀 [Quickstart: Getting Up and Running](https://constructive.io/learn/quickstart)
Get started with modular databases in minutes. Install prerequisites and deploy your first module.
2. 📦 [Modular PostgreSQL Development with Database Packages](https://constructive.io/learn/modular-postgres)
Learn to organize PostgreSQL projects with pgpm workspaces and reusable database modules.
3. ✏️ [Authoring Database Changes](https://constructive.io/learn/authoring-database-changes)
Master the workflow for adding, organizing, and managing database changes with pgpm.
4. 🧪 [End-to-End PostgreSQL Testing with TypeScript](https://constructive.io/learn/e2e-postgres-testing)
Master end-to-end PostgreSQL testing with ephemeral databases, RLS testing, and CI/CD automation.
5. ⚡ [Supabase Testing](https://constructive.io/learn/supabase)
Use TypeScript-first tools to test Supabase projects with realistic RLS, policies, and auth contexts.
6. 💧 [Drizzle ORM Testing](https://constructive.io/learn/drizzle-testing)
Run full-stack tests with Drizzle ORM, including database setup, teardown, and RLS enforcement.
7. 🔧 [Troubleshooting](https://constructive.io/learn/troubleshooting)
Common issues and solutions for pgpm, PostgreSQL, and testing.
## Related Constructive Tooling
### 📦 Package Management
* [pgpm](https://github.com/constructive-io/constructive/tree/main/pgpm/pgpm): **🖥️ PostgreSQL Package Manager** for modular Postgres development. Works with database workspaces, scaffolding, migrations, seeding, and installing database packages.
### 🧪 Testing
* [pgsql-test](https://github.com/constructive-io/constructive/tree/main/postgres/pgsql-test): **📊 Isolated testing environments** with per-test transaction rollbacks—ideal for integration tests, complex migrations, and RLS simulation.
* [pglite-test](https://github.com/constructive-io/constructive/tree/main/postgres/pglite-test): **🪶 Drop-in pgsql-test replacement backed by PGlite** — in-process Postgres, no server required, instance-per-suite isolation.
* [pgsql-seed](https://github.com/constructive-io/constructive/tree/main/postgres/pgsql-seed): **🌱 PostgreSQL seeding utilities** for CSV, JSON, SQL data loading, and pgpm deployment.
* [supabase-test](https://github.com/constructive-io/constructive/tree/main/postgres/supabase-test): **🧪 Supabase-native test harness** preconfigured for the local Supabase stack—per-test rollbacks, JWT/role context helpers, and CI/GitHub Actions ready.
* [graphile-test](https://github.com/constructive-io/constructive/tree/main/graphile/graphile-test): **🔐 Authentication mocking** for Graphile-focused test helpers and emulating row-level security contexts.
* [pg-query-context](https://github.com/constructive-io/constructive/tree/main/postgres/pg-query-context): **🔒 Session context injection** to add session-local context (e.g., `SET LOCAL`) into queries—ideal for setting `role`, `jwt.claims`, and other session settings.
### 🧠 Parsing & AST
* [pgsql-parser](https://www.npmjs.com/package/pgsql-parser): **🔄 SQL conversion engine** that interprets and converts PostgreSQL syntax.
* [libpg-query-node](https://www.npmjs.com/package/libpg-query): **🌉 Node.js bindings** for `libpg_query`, converting SQL into parse trees.
* [pg-proto-parser](https://www.npmjs.com/package/pg-proto-parser): **📦 Protobuf parser** for parsing PostgreSQL Protocol Buffers definitions to generate TypeScript interfaces, utility functions, and JSON mappings for enums.
* [@pgsql/enums](https://www.npmjs.com/package/@pgsql/enums): **🏷️ TypeScript enums** for PostgreSQL AST for safe and ergonomic parsing logic.
* [@pgsql/types](https://www.npmjs.com/package/@pgsql/types): **📝 Type definitions** for PostgreSQL AST nodes in TypeScript.
* [@pgsql/utils](https://www.npmjs.com/package/@pgsql/utils): **🛠️ AST utilities** for constructing and transforming PostgreSQL syntax trees.
### 📚 Documentation & Skills
* [constructive-skills](https://github.com/constructive-io/constructive-skills): **📖 Platform documentation and AI agent skills** — feature catalog, blueprint reference, SDK guides (i18n, billing, limits, events, uploads, security, entities, search, AI), and deployment guides.
Install skills for AI coding agents:
```bash
# All platform skills (security, blueprints, codegen, billing, etc.)
npx skills add constructive-io/constructive-skills
# Individual repo skills (pgpm, testing, CLI, search, etc.)
npx skills add https://github.com/constructive-io/constructive --skill pgpm
npx skills add https://github.com/constructive-io/constructive --skill constructive-testing
```
## Credits
**🛠 Built by the [Constructive](https://constructive.io) team — creators of modular Postgres tooling for secure, composable backends. If you like our work, contribute on [GitHub](https://github.com/constructive-io).**
## Disclaimer
AS DESCRIBED IN THE LICENSES, THE SOFTWARE IS PROVIDED "AS IS", AT YOUR OWN RISK, AND WITHOUT WARRANTIES OF ANY KIND.
No developer or entity involved in creating this software will be liable for any claims or damages whatsoever associated with your use, inability to use, or your interaction with other users of the code, including any direct, indirect, incidental, special, exemplary, punitive or consequential damages, or loss of profits, cryptocurrencies, tokens, or anything else of value.