diff --git a/README.md b/README.md
index 0799213..b795ccf 100644
--- a/README.md
+++ b/README.md
@@ -81,18 +81,30 @@ Tagged commits trigger CI to publish:
 - npm (public): [`@o1-labs/mina-archive-node-graphql`](https://www.npmjs.com/package/@o1-labs/mina-archive-node-graphql)
 - Docker (GHCR): `ghcr.io/o1-labs/archive-node-api`
 
-To cut a release:
+Normal releases after `1.0.0` are cut with:
 
 ```sh
 npm version <major|minor|patch>
 git push --follow-tags
 ```
 
-CI builds, publishes the npm package with provenance, and pushes Docker tags `1.2.3`, `1.2`, `1`, `latest`.
+For the initial `1.0.0` tag and current npm trusted-publishing caveat, see
+the [versioning & schema stability policy](./docs/versioning.md#releasing).
+
+CI builds, publishes the npm package with provenance once npm trusted
+publishing is configured, and pushes Docker tags `1.2.3`, `1.2`, `1`,
+`latest`.
+
+From 1.0.0 the GraphQL schema, HTTP endpoints, and configuration are a versioned public contract — see the [versioning & schema stability policy](./docs/versioning.md) for what counts as a breaking change and how deprecations work.
 
 ## Hardware requirements
 
-The bottleneck is the Postgres database, not this server. For production load, point `PG_CONN` at multiple read replicas — the server fans queries across them and recovers automatically as hosts come and go. A recent benchmark on a 12-core / 32 GB box (API + Postgres co-located) sustained ~800 req/s with p99 latency of 39 ms. Use `npm run benchmark` to size your own deployment.
+The bottleneck is the Postgres database, not this server. Listing multiple hosts
+in `PG_CONN` gives failover, not read fan-out; put a load balancer or managed
+reader endpoint in front of read replicas when you need to spread query load. A
+recent benchmark on a 12-core / 32 GB box (API + Postgres co-located) sustained
+~800 req/s with p99 latency of 39 ms. Use `npm run benchmark` to size your own
+deployment.
 
 For SLOs, capacity guidance, what to monitor, and incident response, see the [operations runbook](./docs/runbook.md).
 
diff --git a/docs/getting-started.md b/docs/getting-started.md
index e46c25e..f184168 100644
--- a/docs/getting-started.md
+++ b/docs/getting-started.md
@@ -76,7 +76,7 @@ Use this when you already have an archive-node Postgres reachable but don't want
 docker pull ghcr.io/o1-labs/archive-node-api:latest
 
 # or pin a specific version (recommended for production)
-docker pull ghcr.io/o1-labs/archive-node-api:0.0.6
+docker pull ghcr.io/o1-labs/archive-node-api:1.0.0
 ```
 
 ### 2. Run
diff --git a/docs/versioning.md b/docs/versioning.md
new file mode 100644
index 0000000..df7c7a9
--- /dev/null
+++ b/docs/versioning.md
@@ -0,0 +1,155 @@
+# Versioning & Schema Stability Policy
+
+From **1.0.0** onward the Archive Node API follows [Semantic Versioning](https://semver.org/)
+and treats its **GraphQL schema**, **HTTP endpoints**, and **configuration** as the
+public contract.
+
+## What the version numbers mean
+
+Given `MAJOR.MINOR.PATCH`:
+
+- **MAJOR** — a backwards-incompatible change to the public contract (see
+  "Breaking changes" below). Consumers may need to update queries or config.
+- **MINOR** — backwards-compatible additions: new schema fields/types/arguments,
+  new optional config, new endpoints. Existing queries keep working.
+- **PATCH** — backwards-compatible bug fixes and internal changes.
+
+## What counts as a breaking change
+
+GraphQL schema:
+
+- Removing or renaming a type, field, enum value, or argument.
+- Changing a field's type.
+- **Output fields:** making a non-null field nullable (`String!` → `String`).
+  Clients written against the guarantee may now receive `null` where they
+  cannot handle it. The reverse — `String` → `String!` — only strengthens the
+  guarantee and is safe.
+- **Arguments and input fields:** making a nullable argument non-null
+  (`String` → `String!`), which rejects callers that were legitimately omitting
+  it. Here the reverse is the safe direction — the mirror image of output
+  fields, because the client is the one supplying the value.
+- Adding a required (non-null, no-default) argument to an existing field.
+
+Operational contract:
+
+- Removing or renaming an environment variable, or changing its default in a way
+  that alters behaviour.
+- Removing or renaming an HTTP endpoint (`/`, `/healthcheck`, `/readiness`,
+  `/metrics`).
+- Raising the minimum supported Node.js runtime, whether through `engines`, the
+  Docker base image, or the Node version used by CI to publish the package.
+- Enabling by default behaviour that can reject, throttle, or block a request
+  that was previously accepted, such as rate limiting, request-size caps,
+  query-cost limits, or a stricter CORS allowlist.
+
+Additive counterparts of the above (new optional field, new nullable argument,
+new env var with a safe default) are **minor**, not breaking.
+
+## Flag-gating behaviour changes
+
+Changes that alter **default response shape or content**, or the **set of exposed
+queries**, ship **disabled by default behind an environment flag** — the practice
+this repo already follows with `ENABLE_BLOCK_TRANSACTION_DETAILS` (gates
+block-detail output) and `ENABLED_QUERIES` (allowlists the exposed query
+surface).
+
+- A flagged, default-off change is **minor**.
+- Flipping such a default on — or removing the flag so the new behaviour is
+  unconditional — changes what existing clients receive out of the box, and is
+  **major**.
+
+Correcting a result that was demonstrably wrong is a bug fix, not a flagged
+behaviour change. Call the fix out explicitly in the release notes with the
+before/after shape so consumers know why content changed.
+
+This is what lets consumers survive upgrades. The
+[mina-explorer](https://github.com/o1-labs/mina-explorer) fires fallback query
+chains and degrades on the exact `"Cannot query field"` validation error, so it
+tolerates a field it doesn't know about — but not a *default response* that
+quietly changes shape. An unflagged change there doesn't error; it blanks
+Explorer pages while every health check stays green. That failure mode is why
+this is a rule rather than a convention: the schema checker cannot catch it,
+because nothing about the schema is technically breaking.
+
+## Error messages and validation behaviour
+
+GraphQL validation and parse errors are part of the public contract. Clients use
+them for capability detection: they probe for a field or filter and fall back
+based on the error text.
+
+Covered by this policy:
+
+- Validation and parse errors must be returned in `errors[]` with their verbatim
+  `graphql-js` wording, including `Cannot query field "X" on type "Y".`,
+  `Unknown argument "X" on field "Y".`, `Unknown type "X".`, and unknown
+  input-field errors that name the field, such as `inBestChain`.
+- `errors[]` must still be present in the response body when the HTTP status is
+  non-2xx; clients parse the body regardless of status code.
+- Error masking applies to unexpected thrown runtime errors only. Widening it to
+  cover validation or parse errors, or replacing their text with a generic
+  string, error code, or redacted message, is **major**.
+
+Known consumers match this text today:
+[mina-explorer](https://github.com/o1-labs/mina-explorer) checks for
+`inBestChain`, while mina-explorer-api checks for `Cannot query field`,
+`Unknown argument`, `Unknown type`, and `inBestChain`. As with flag-gating,
+breaking this does not fail loudly: the schema checker stays green, health
+checks stay green, and consumers may serve empty views.
+
+## Deprecation policy
+
+We prefer deprecation over removal:
+
+1. Mark schema elements with the `@deprecated(reason: "…")` directive, pointing to
+   the replacement and planned removal target, for example
+   `"Use X. Removed in 2.0.0, no earlier than 2026-11-15."`.
+2. Announce the deprecation in the GitHub release notes for the minor that
+   introduces it. The 90-day clock starts when that release is published.
+3. Keep the deprecated element working for **at least one minor release and 90
+   days**, whichever is later, before removing it in a subsequent **major**.
+
+Environment variables follow the same path: continue honouring the old name
+(with a startup warning) for one minor + 90 days before removal.
+
+## Enforcement
+
+Schema changes are checked in CI by **graphql-inspector** (the "Check Schema"
+job). A change it flags as breaking fails the build unless the PR carries the
+`expected-breaking-change` label — so every breaking change is a deliberate,
+reviewed decision that must be paired with a major version bump.
+
+## Releasing
+
+Releases are cut from `main` by a maintainer:
+
+```sh
+npm version <major|minor|patch>   # bumps package.json + creates a git tag
+git push --follow-tags            # tag push triggers the publish pipeline
+```
+
+For the initial `1.0.0` release only, `package.json` on `main` already carries
+the version to release. Tag it directly (`git tag v1.0.0 && git push
+--follow-tags`) rather than running `npm version`, which would bump past it.
+
+CI then builds and publishes the npm package (with provenance, once npm trusted
+publishing is configured for this repository) and the Docker images. Choose the
+bump level according to the rules above.
+
+## Migrating from npm `0.0.6`
+
+Tags `0.0.7` through `0.0.9` existed in git but were not published to npm, so
+npm consumers should treat `1.0.0` as an upgrade from `0.0.6`. Review these
+operator-visible changes before rolling out:
+
+- Browser deployments must set `CORS_ORIGIN` deliberately.
+- Rate limiting is enabled and depends on the correct `TRUST_PROXY` hop count.
+- The supported Node.js runtime moves to Node 22.
+- Boolean environment variables reject junk values instead of relying on
+  JavaScript truthiness.
+- `actions` result semantics include correctness fixes called out in the release
+  notes.
+
+## Supported versions
+
+The latest released **MAJOR.MINOR** receives bug and security fixes. Older lines
+are supported on a best-effort basis.
diff --git a/package-lock.json b/package-lock.json
index 3d57615..8a1e739 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@o1-labs/mina-archive-node-graphql",
-  "version": "0.0.9",
+  "version": "1.0.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@o1-labs/mina-archive-node-graphql",
-      "version": "0.0.9",
+      "version": "1.0.0",
       "license": "ISC",
       "dependencies": {
         "@envelop/core": "^4.0.0",
diff --git a/package.json b/package.json
index f187cfa..edc7256 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@o1-labs/mina-archive-node-graphql",
-  "version": "0.0.9",
+  "version": "1.0.0",
   "description": "A NodeJS GraphQL server for exposing Mina Protocol archive node data for o1js/zkApps",
   "repository": {
     "type": "git",