diff --git a/CHANGELOG.md b/CHANGELOG.md
index 210166531..40182cb8e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,159 @@
 # Change Log
+## 1.0.0 (03/31/2026)
+> [!IMPORTANT]
+> This is the first GA release of Smithy Java. All client modules are now considered stable.
+> Some modules, including server, CLI, and MCP, are still in developer-preview and may contain bugs.
+> No guarantee is made about their API stability. Unstable modules are marked with a warning in their
+> `README.md` and with the `@SmithyUnstableApi` annotation in their `package-info.java`.
+
+### Features
+- Added endpoint rules engine with BDD codegen, fused opcodes, and peephole optimizations. ([#1035](https://github.com/smithy-lang/smithy-java/pull/1035))
+- Added support for AWS Query protocol in the client.
+- Added support for request compression. ([#968](https://github.com/smithy-lang/smithy-java/pull/968))
+- Added checksum support in requests. ([#911](https://github.com/smithy-lang/smithy-java/pull/911))
+- Added event streams support to AWS JSON protocols. ([#1076](https://github.com/smithy-lang/smithy-java/pull/1076))
+- Added event stream implementation for RPCv2. ([#849](https://github.com/smithy-lang/smithy-java/pull/849))
+- Added support for `@eventHeader` and `@eventPayload` for RPC protocols. ([#864](https://github.com/smithy-lang/smithy-java/pull/864))
+- Added event stream signing support. ([#1054](https://github.com/smithy-lang/smithy-java/pull/1054))
+- Implemented new event streams API. ([#1035](https://github.com/smithy-lang/smithy-java/pull/1035))
+- Added an OpenTelemetry based plugin to publish operation metrics. ([#1030](https://github.com/smithy-lang/smithy-java/pull/1030))
+- Added support for native remote MCP servers. ([#943](https://github.com/smithy-lang/smithy-java/pull/943))
+- Added MCP ping request support. ([#1016](https://github.com/smithy-lang/smithy-java/pull/1016))
+- Added MCP proxy server support for prompts.
+- Added MCP metrics observer support to McpServerBuilder.
+- Added support for SSE + streaming with MCP notifications.
+- Added structured content to MCP tool responses when possible.
+- Added output schema to MCP tools/list.
+- Added protocol version to MCP initialize response.
+- Added workingDirectory to StdioProxy.
+- Added error response parsing for restXml. ([#922](https://github.com/smithy-lang/smithy-java/pull/922))
+- Added support for BigDecimal Documents in CBOR.
+- Added map input for dynamic client.
+- Added `DataStream.writeTo()` and IO utilities.
+- Added `isAvailable` to check if DataStream has not been consumed.
+- Added close to DataStream to allow closing resources.
+- Added generic types to JMESPath predicates. ([#1067](https://github.com/smithy-lang/smithy-java/pull/1067))
+- Added utility to fill shapes with random values.
+- Added fuzz testing framework.
+- Added document discriminator sanitizer for JSON protocols. ([#932](https://github.com/smithy-lang/smithy-java/pull/932))
+- Added plugin phases, auto-plugins, and hierarchy for codegen.
+- Added ability to register default plugins in codegen.
+- Added new code sections to support deserialization overrides.
+- Added plugin test runner. ([#855](https://github.com/smithy-lang/smithy-java/pull/855))
+- Added compile method for EndpointRuleSet in RulesEngineBuilder.
+- Added singletons for AwsCredentialsResolver implementations. ([#1059](https://github.com/smithy-lang/smithy-java/pull/1059))
+- Added strategy for writing error types to headers.
+- Added ModifiableHttpHeaders method to overwrite HTTP header values.
+- Generated input shape with additionalInput member for operations with Unit input.
+- Added model bundle version to decide whether to wrap input or not.
+- Added additionalInfo to BundleMetadata.
+- Allowed event processors to compose. ([#1095](https://github.com/smithy-lang/smithy-java/pull/1095))
+- Allowed lists to be marked as httpPayload.
+- Added KEYS synchronization.
+- Added HttpTransportConfig for transport settings.
+
+### Bug Fixes
+- Fixed CBOR deserializer crash on empty input for no-input operations. ([#1103](https://github.com/smithy-lang/smithy-java/pull/1103))
+- Fixed protocol initialization for AwsRestJson1Protocol. ([#1023](https://github.com/smithy-lang/smithy-java/pull/1023))
+- Fixed incorrect codegen for HttpApiKeyAuthTrait.
+- Fixed encoding/decoding of errors and exception events. ([#1055](https://github.com/smithy-lang/smithy-java/pull/1055))
+- Fixed SchemaIndex collision for Unit inputs/outputs.
+- Fixed handling of timestamps inside oneOf unions.
+- Fixed handling of event payload members of blob and string type. ([#1064](https://github.com/smithy-lang/smithy-java/pull/1064))
+- Fixed bug of adding a null element to the list when list is empty or null.
+- Fixed Sigv4 multivalued query key ordering and double path encoding. ([#984](https://github.com/smithy-lang/smithy-java/pull/984))
+- Fixed query params with more than one value per key. ([#973](https://github.com/smithy-lang/smithy-java/pull/973))
+- Fixed double encoding URIs for signing. ([#972](https://github.com/smithy-lang/smithy-java/pull/972))
+- Fixed httpQuery related protocol tests. ([#945](https://github.com/smithy-lang/smithy-java/pull/945))
+- Fixed httpHeader and httpPrefixHeaders protocol tests. ([#914](https://github.com/smithy-lang/smithy-java/pull/914))
+- Fixed QueryCustomizedError protocol test.
+- Fixed type conversion issues in MCP.
+- Fixed naming conflict between class name and Schema field when structure name is all capitals.
+- Fixed name conflicts resolving. ([#902](https://github.com/smithy-lang/smithy-java/pull/902))
+- Fixed builder setters to use the correct boxed or primitive type.
+- Fixed javadoc link. ([#987](https://github.com/smithy-lang/smithy-java/pull/987))
+- Fixed URI concat issue with HttpClientProtocol.
+- Fixed bytecode loading and creation.
+- Fixed O(N!) allocations for recursive union variants.
+- Fixed content-type for http-payload when already in headers.
+- Fixed skipping OperationGenerator in types-only codegen mode.
+- Fixed gradle to generate javadoc and sources jar for publishing. ([#854](https://github.com/smithy-lang/smithy-java/pull/854))
+- Fixed delay publishing the initial event until fully wired. ([#865](https://github.com/smithy-lang/smithy-java/pull/865))
+- Fixed null protocol version handling in MCP requests.
+- Fixed proxy initialization failures no longer silently swallowed.
+- Correctly handled BigInteger and BigDecimal defaults.
+- Correctly adapted oneOf unions nested in oneOfUnions.
+- Properly supported lists of Documents. ([#869](https://github.com/smithy-lang/smithy-java/pull/869))
+
+### Improvements
+- Switched to faster and cheaper array-backed headers.
+- Optimized Context implementation with chunked array storage.
+- Optimized SchemaConverter and MCP Schema conversion.
+- Optimized string validation.
+- Optimized endpoints VM with fused opcodes, `ite`, negative indexing, and `SPLIT` opcode.
+- Optimized timestamp handling with minor improvements.
+- Avoided unnecessary UTF-8 decoding and byte[] allocations when flushing MCP structs.
+- Avoided boxing for primitive Documents and fixed equals for various Documents.
+- Used SmithyUri instead of URI for performance.
+- Improved HttpHeaders to only allocate names when needed.
+- Added upper bound on container pre-allocation during deserialization.
+- Prevented allocating large arrays based on BigInteger lengths.
+- Added stricter verifications while reading lists in Json Codec.
+- Added better header and value validation.
+- Improved client content-type deserialization handling.
+- Converted Jackson exceptions to SerializationException.
+- Used JmespathRuntime for JMESPath evaluation.
+- Used proper classloader for loading services. ([#958](https://github.com/smithy-lang/smithy-java/pull/958))
+- Used symbols instead of hardcoded strings. ([#1072](https://github.com/smithy-lang/smithy-java/pull/1072))
+- Used sealed interfaces for enums and records for unions.
+- Oriented DataStream around InputStream.
+- Made Client implement Closeable.
+- Made ClientTransport extend Closeable.
+- Made rules engine independent of client.
+- Moved to blocking client, towards virtual threads.
+- Increased default MCP HTTP proxy timeout from 60s to 5 minutes.
+- Upgraded to Jackson 3.0.3.
+
+### Documentation
+- Added package info and unstable annotations. ([#1094](https://github.com/smithy-lang/smithy-java/pull/1094))
+- Reviewed and annotated public classes with unstable annotation as needed. ([#1077](https://github.com/smithy-lang/smithy-java/pull/1077))
+- Added docs and tests for FormUrlEncodedSink.
+- Added message member to DocumentException toString.
+- Used snippets for code comments.
+
+### Breaking Changes
+- Removed tracing API. ([#1068](https://github.com/smithy-lang/smithy-java/pull/1068))
+- Removed ExternalSymbols.
+- Removed MCP CLI functionality.
+- Removed MCP bundles module.
+- Removed unused ExecutorService from call context.
+- Removed map* methods from Hooks and replaced with cast.
+- Removed logic to deserialize using the protocol codec. ([#870](https://github.com/smithy-lang/smithy-java/pull/870))
+- Removed default from JsonArraySchema.
+- Removed unused jline dependency.
+- Split codegen-plugins back into codegen-core and removed client-api. ([#1091](https://github.com/smithy-lang/smithy-java/pull/1091))
+- Moved from plugin-based codegen to mode-based codegen for types, client, and server.
+- Moved endpoints to upper level.
+- Separated java and resources into different folders. ([#1078](https://github.com/smithy-lang/smithy-java/pull/1078))
+- Surface area review of client packages. ([#1086](https://github.com/smithy-lang/smithy-java/pull/1086))
+- Surface area review of CLI package API. ([#1085](https://github.com/smithy-lang/smithy-java/pull/1085))
+- Made errorSchemas non-default in the interface.
+- Made union members implicitly type-cast in getValue.
+- Made additionalProperties a Document.
+
+### Other
+- Bumped dependencies across multiple Gradle groups.
+- Bumped Gradle actions, checkout, upload-artifact, cache, and setup-java actions.
+- Added integration tests to compile and check AWS endpoints.
+- Added S3 model from Maven.
+- Updated to latest Smithy with stricter BDD validation.
+- Built examples explicitly using JDK21.
+- Made mcp-schemas and smithy-ai-traits jars reproducible.
+- Fixed build cache misses.
+- Moved examples and mcp-schemas to new structure.
+- Tests and codegen fixes to build most AWS API models. ([#1081](https://github.com/smithy-lang/smithy-java/pull/1081))
+- Removed build warnings. ([#1109](https://github.com/smithy-lang/smithy-java/pull/1109))
+
 ## 0.0.3 (08/21/2025)
 > [!WARNING]
 > This is a developer-preview release and may contain bugs. **No** guarantee is made about API stability.
@@ -69,4 +224,4 @@
 - Added JSON protocol support - restJson1, awsJson.
 - Added RPCV2 CBOR protocol support.
 - Implemented Dynamic client that can load a Smithy model to call a service.
-- Added Smithy Lambda Endpoint wrapper to run generated server stubs in AWS Lambda.
\ No newline at end of file
+- Added Smithy Lambda Endpoint wrapper to run generated server stubs in AWS Lambda.
diff --git a/VERSION b/VERSION
index 2c91216aa..3eefcb9dd 100644
--- a/VERSION
+++ b/VERSION
@@ -1,2 +1 @@
-0.0.3
-
+1.0.0
diff --git a/aws/aws-service-bundle/README.md b/aws/aws-service-bundle/README.md
new file mode 100644
index 000000000..53f3f9c62
--- /dev/null
+++ b/aws/aws-service-bundle/README.md
@@ -0,0 +1,7 @@
+## aws-service-bundle
+
+> [!WARNING]
+> This is a developer-preview module and may contain bugs. No guarantee is made about API stability.
+> This module is not recommended for production use.
+
+Provides generic request parameters for interacting with AWS services described by an AWS service bundle.
diff --git a/aws/aws-service-bundler/README.md b/aws/aws-service-bundler/README.md
new file mode 100644
index 000000000..86700bbed
--- /dev/null
+++ b/aws/aws-service-bundler/README.md
@@ -0,0 +1,7 @@
+## aws-service-bundler
+
+> [!WARNING]
+> This is a developer-preview module and may contain bugs. No guarantee is made about API stability.
+> This module is not recommended for production use.
+
+Produces service bundles for AWS services from Smithy models.
diff --git a/aws/integrations/aws-lambda-endpoint/README.md b/aws/integrations/aws-lambda-endpoint/README.md
new file mode 100644
index 000000000..7c0a917f6
--- /dev/null
+++ b/aws/integrations/aws-lambda-endpoint/README.md
@@ -0,0 +1,7 @@
+## aws-lambda-endpoint
+
+> [!WARNING]
+> This is a developer-preview module and may contain bugs. No guarantee is made about API stability.
+> This module is not recommended for production use.
+
+Provides an endpoint implementation for running Smithy Java server stubs as AWS Lambda request handlers.
diff --git a/cli/README.md b/cli/README.md
index c11eff958..d57c2bafa 100644
--- a/cli/README.md
+++ b/cli/README.md
@@ -1,7 +1,8 @@
 ## smithy-call
 
 > [!WARNING]
-> This project is still in development and is not intended for use in production.
+> This is a developer-preview module and may contain bugs. No guarantee is made about API stability.
+> This module is not recommended for production use.
 
 This module contains the base-version of smithy-call: a CLI that uses ahead-of-time compilation and the dynamic client to make adhoc calls to services.
 
diff --git a/codegen/test-utils/README.md b/codegen/test-utils/README.md
new file mode 100644
index 000000000..cf6b97750
--- /dev/null
+++ b/codegen/test-utils/README.md
@@ -0,0 +1,7 @@
+## codegen-test-utils
+
+> [!WARNING]
+> This is a developer-preview module and may contain bugs. No guarantee is made about API stability.
+> This module is not recommended for production use.
+
+Provides utilities for testing Smithy Java codegen plugins.
diff --git a/mcp/mcp-server/README.md b/mcp/mcp-server/README.md
new file mode 100644
index 000000000..f0efe0096
--- /dev/null
+++ b/mcp/mcp-server/README.md
@@ -0,0 +1,7 @@
+## mcp-server
+
+> [!WARNING]
+> This is a developer-preview module and may contain bugs. No guarantee is made about API stability.
+> This module is not recommended for production use.
+
+Provides Model Context Protocol (MCP) server support for Smithy Java, enabling MCP server generation from Smithy models.
diff --git a/model-bundle/model-bundle-api/README.md b/model-bundle/model-bundle-api/README.md
new file mode 100644
index 000000000..34e1ebb60
--- /dev/null
+++ b/model-bundle/model-bundle-api/README.md
@@ -0,0 +1,7 @@
+## model-bundle-api
+
+> [!WARNING]
+> This is a developer-preview module and may contain bugs. No guarantee is made about API stability.
+> This module is not recommended for production use.
+
+Implements the model-bundle utility for packaging and loading Smithy models at runtime.
diff --git a/server/server-api/README.md b/server/server-api/README.md
index f30a49977..6792ff220 100644
--- a/server/server-api/README.md
+++ b/server/server-api/README.md
@@ -1,2 +1,7 @@
 ## server-api
+
+> [!WARNING]
+> This is a developer-preview module and may contain bugs. No guarantee is made about API stability.
+> This module is not recommended for production use.
+
 Provides the base API for servers.
diff --git a/server/server-core/README.md b/server/server-core/README.md
index 28da3cc4c..b8610f21c 100644
--- a/server/server-core/README.md
+++ b/server/server-core/README.md
@@ -1,2 +1,7 @@
 ## server-core
+
+> [!WARNING]
+> This is a developer-preview module and may contain bugs. No guarantee is made about API stability.
+> This module is not recommended for production use.
+
 Provides core server functionality for the Smithy Java framework.
diff --git a/server/server-netty/README.md b/server/server-netty/README.md
index fc24c502c..6df3dff15 100644
--- a/server/server-netty/README.md
+++ b/server/server-netty/README.md
@@ -1,2 +1,7 @@
 ## server-netty
+
+> [!WARNING]
+> This is a developer-preview module and may contain bugs. No guarantee is made about API stability.
+> This module is not recommended for production use.
+
 Netty-based implementation of a Smithy Java server.
diff --git a/server/server-proxy/README.md b/server/server-proxy/README.md
new file mode 100644
index 000000000..9a06248ea
--- /dev/null
+++ b/server/server-proxy/README.md
@@ -0,0 +1,7 @@
+## server-proxy
+
+> [!WARNING]
+> This is a developer-preview module and may contain bugs. No guarantee is made about API stability.
+> This module is not recommended for production use.
+
+Provides proxy server functionality for the Smithy Java framework, enabling request forwarding using the dynamic client.
diff --git a/server/server-rpcv2-cbor/README.md b/server/server-rpcv2-cbor/README.md
index 55f259a9e..6caa8f115 100644
--- a/server/server-rpcv2-cbor/README.md
+++ b/server/server-rpcv2-cbor/README.md
@@ -1,2 +1,7 @@
-### server-rpcv2-cbor
+## server-rpcv2-cbor
+
+> [!WARNING]
+> This is a developer-preview module and may contain bugs. No guarantee is made about API stability.
+> This module is not recommended for production use.
+
 Server implementation of the [RPCv2](https://smithy.io/2.0/additional-specs/protocols/smithy-rpc-v2.html) CBOR protocol.
diff --git a/smithy-ai-traits/README.md b/smithy-ai-traits/README.md
new file mode 100644
index 000000000..aa93be93b
--- /dev/null
+++ b/smithy-ai-traits/README.md
@@ -0,0 +1,7 @@
+## smithy-ai-traits
+
+> [!WARNING]
+> This is a developer-preview module and may contain bugs. No guarantee is made about API stability.
+> This module is not recommended for production use.
+
+Defines Smithy AI traits for annotating models with AI-specific metadata such as prompts and tool definitions.