diff --git a/.github/workflows/release-fork.yml b/.github/workflows/release-fork.yml
index a4cc07dd4..49381ddbd 100644
--- a/.github/workflows/release-fork.yml
+++ b/.github/workflows/release-fork.yml
@@ -5,15 +5,16 @@
 #           LeXwDeX/opencode fork. Stripped-down version of upstream
 #           publish.yml — removes repo guard, Blacksmith runners, code
 #           signing, npm publish, and Tauri desktop.
-# Trigger : Manual workflow_dispatch (PRIMARY) — pick branch + version
+# Trigger : Manual workflow_dispatch (PRIMARY) — pick main or dev
 #           Push to main/dev ONLY registers the workflow in the Actions UI
 #           (the build job is gated on `github.event_name == 'workflow_dispatch'`)
-# Inputs  : version        — release version string (e.g. "1.14.30-fork.2")
-#                            Leave blank for auto timestamped version.
-#           create_release — when true, create a GitHub Release with the
+# Version : Independent GraphAgent SemVer derived only from graphagent-v* tags.
+#           dev builds the next stable version as X.Y.Z-dev.N; main publishes
+#           X.Y.Z and marks it Latest. OpenCode package versions are ignored.
+# Inputs  : create_release — when true, create a GitHub Release with the
 #                            built binaries + SHA256SUMS attached. Builds
-#                            from any branch other than `main` are marked
-#                            prerelease (test build); `main` = formal release.
+#                            from `dev` are marked prerelease (test build);
+#                            `main` builds are formal and become Latest.
 #           platforms      — comma-separated subset of linux,macos,windows
 #                            to build. Leave blank to build all three.
 # Jobs    : package-templates — package latest reference templates from the
@@ -31,15 +32,11 @@ on:
   # Manual trigger — the primary way to build releases
   workflow_dispatch:
     inputs:
-      version:
-        description: "Release version (e.g. 1.14.30-fork.2). Leave blank for auto."
-        required: false
-        type: string
       create_release:
         description: "Create a GitHub Release with the built binaries"
         required: false
         type: boolean
-        default: false
+        default: true
       platforms:
         description: "Platforms to build, comma-separated (linux,macos,windows). Leave blank for all."
         required: false
@@ -58,7 +55,36 @@ permissions:
 env:
   FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: false
 
+concurrency:
+  group: release-fork
+  cancel-in-progress: false
+
 jobs:
+  version:
+    name: Resolve GraphAgent Version
+    if: github.event_name == 'workflow_dispatch'
+    runs-on: ubuntu-latest
+    outputs:
+      channel: ${{ steps.release-version.outputs.channel }}
+      version: ${{ steps.release-version.outputs.version }}
+      tag: ${{ steps.release-version.outputs.tag }}
+      prerelease: ${{ steps.release-version.outputs.prerelease }}
+      latest: ${{ steps.release-version.outputs.latest }}
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Setup Bun
+        uses: ./.github/actions/setup-bun
+        with:
+          save-cache: false
+
+      - name: Resolve Version
+        id: release-version
+        run: bun run ./packages/opencode/script/release-version.ts
+
   # Package the latest reference templates from the dedicated config repo
   # (LeXwDeX/opencode-dag-config) into a release asset. dev/main do not manage
   # these templates anymore — the config repo is the single source of truth.
@@ -98,7 +124,7 @@ jobs:
 
   build-cli:
     name: Build CLI (${{ matrix.name }})
-    needs: package-templates
+    needs: [version, package-templates]
     # Skip the actual build when triggered by push (registration-only). Per-
     # matrix-entry platform filtering can't live here — `matrix` isn't in
     # scope for a job-level `if:` — so it's applied to each step below instead.
@@ -182,8 +208,8 @@ jobs:
         if: inputs.platforms == '' || contains(inputs.platforms, matrix.name)
         run: ./packages/opencode/script/build.ts --single --skip-install
         env:
-          OPENCODE_CHANNEL: latest
-          OPENCODE_VERSION: ${{ inputs.version || '' }}
+          OPENCODE_CHANNEL: ${{ needs.version.outputs.channel == 'main' && 'latest' || 'dev' }}
+          OPENCODE_VERSION: ${{ needs.version.outputs.version }}
 
       # Bundle ripgrep into each dist/opencode-*/bin so air-gapped users do not
       # hit the runtime download in packages/core/src/ripgrep/binary.ts.
@@ -221,7 +247,7 @@ jobs:
 
   release:
     name: Create GitHub Release
-    needs: [build-cli, package-templates]
+    needs: [version, build-cli, package-templates]
     if: inputs.create_release
     runs-on: ubuntu-latest
     steps:
@@ -234,16 +260,6 @@ jobs:
           path: release-assets
           merge-multiple: true
 
-      - name: Determine Version Tag
-        id: tag
-        run: |
-          VER="${{ inputs.version }}"
-          if [ -z "$VER" ]; then
-            VER="0.0.0-$(date +%Y%m%d%H%M)"
-          fi
-          echo "version=$VER" >> "$GITHUB_OUTPUT"
-          echo "tag=v$VER" >> "$GITHUB_OUTPUT"
-
       - name: Generate SHA256SUMS
         working-directory: release-assets
         run: |
@@ -254,17 +270,18 @@ jobs:
       - name: Create GitHub Release
         env:
           GH_TOKEN: ${{ github.token }}
-        # Releases built from any branch other than `main` (e.g. `dev`) are
-        # test builds and get marked --prerelease; only `main` produces a
-        # formal release.
+        # dev releases are prereleases and can never become Latest. main
+        # releases are formal and are explicitly promoted to Latest.
         run: |
           EXTRA_FLAGS=()
-          if [ "${{ github.ref_name }}" != "main" ]; then
-            EXTRA_FLAGS+=(--prerelease)
+          if [ "${{ needs.version.outputs.channel }}" = "main" ]; then
+            EXTRA_FLAGS+=(--latest)
+          else
+            EXTRA_FLAGS+=(--prerelease --latest=false)
           fi
-          gh release create "${{ steps.tag.outputs.tag }}" \
-            --title "opencode ${{ steps.tag.outputs.version }}" \
-            --notes "Fork release from branch ${{ github.ref_name }}" \
+          gh release create "${{ needs.version.outputs.tag }}" \
+            --title "OpenCode GraphAgent v${{ needs.version.outputs.version }}" \
+            --notes "GraphAgent release from branch ${{ github.ref_name }}" \
             --target "${{ github.sha }}" \
             "${EXTRA_FLAGS[@]}" \
             release-assets/*
diff --git a/packages/opencode/script/release-version.ts b/packages/opencode/script/release-version.ts
new file mode 100644
index 000000000..5f8cddecb
--- /dev/null
+++ b/packages/opencode/script/release-version.ts
@@ -0,0 +1,116 @@
+const tagPrefix = "graphagent-v"
+const stableTag = /^graphagent-v(\d+)\.(\d+)\.(\d+)$/
+const devTag = /^graphagent-v(\d+)\.(\d+)\.(\d+)-dev\.(\d+)$/
+
+type Version = readonly [major: number, minor: number, patch: number]
+
+export function resolveReleaseVersion(input: { branch: string; tags: string[] }) {
+  const channel = input.branch
+  if (channel !== "main" && channel !== "dev") {
+    throw new Error(`GraphAgent releases require main or dev, received: ${channel || "(empty)"}`)
+  }
+
+  const latest = input.tags
+    .flatMap((tag) => {
+      const version = parseStableTag(tag)
+      return version ? [version] : []
+    })
+    .toSorted(compareVersion)
+    .at(-1)
+  const target = nextVersion(latest)
+  const base = target.join(".")
+
+  if (channel === "main") {
+    return {
+      channel,
+      version: base,
+      tag: `${tagPrefix}${base}`,
+      prerelease: false,
+      latest: true,
+    }
+  }
+
+  const sequence =
+    Math.max(
+      0,
+      ...input.tags.flatMap((tag) => {
+        const parsed = parseDevTag(tag)
+        return parsed && sameVersion(parsed.version, target) ? [parsed.sequence] : []
+      }),
+    ) + 1
+  const version = `${base}-dev.${sequence}`
+  return {
+    channel,
+    version,
+    tag: `${tagPrefix}${version}`,
+    prerelease: true,
+    latest: false,
+  }
+}
+
+function parseStableTag(tag: string): Version | undefined {
+  const match = stableTag.exec(tag)
+  if (!match) return undefined
+  return [Number(match[1]), Number(match[2]), Number(match[3])]
+}
+
+function parseDevTag(tag: string) {
+  const match = devTag.exec(tag)
+  if (!match) return undefined
+  return {
+    version: [Number(match[1]), Number(match[2]), Number(match[3])] as Version,
+    sequence: Number(match[4]),
+  }
+}
+
+function nextVersion(version: Version | undefined): Version {
+  if (!version) return [1, 0, 0]
+  return [version[0], version[1], version[2] + 1]
+}
+
+function compareVersion(left: Version, right: Version) {
+  return left[0] - right[0] || left[1] - right[1] || left[2] - right[2]
+}
+
+function sameVersion(left: Version, right: Version) {
+  return left[0] === right[0] && left[1] === right[1] && left[2] === right[2]
+}
+
+async function readTags() {
+  const child = Bun.spawn(["git", "tag", "--list", `${tagPrefix}*`], {
+    stdout: "pipe",
+    stderr: "pipe",
+  })
+  const [stdout, stderr, exitCode] = await Promise.all([
+    new Response(child.stdout).text(),
+    new Response(child.stderr).text(),
+    child.exited,
+  ])
+  if (exitCode !== 0) throw new Error(`Unable to list GraphAgent tags: ${stderr.trim()}`)
+  return stdout.split(/\r?\n/).filter(Boolean)
+}
+
+async function main() {
+  const output = process.env.GITHUB_OUTPUT
+  if (!output) throw new Error("GITHUB_OUTPUT is required")
+
+  const release = resolveReleaseVersion({
+    branch: process.env.GITHUB_REF_NAME ?? "",
+    tags: await readTags(),
+  })
+  const { appendFile } = await import("node:fs/promises")
+  await appendFile(
+    output,
+    [
+      `channel=${release.channel}`,
+      `version=${release.version}`,
+      `tag=${release.tag}`,
+      `prerelease=${release.prerelease}`,
+      `latest=${release.latest}`,
+      "",
+    ].join("\n"),
+  )
+  console.log(`GraphAgent release: ${release.tag} (channel=${release.channel}, latest=${release.latest})`)
+}
+
+if (import.meta.main) await main()
diff --git a/packages/opencode/test/release-version.test.ts b/packages/opencode/test/release-version.test.ts
new file mode 100644
index 000000000..e0542d9ad
--- /dev/null
+++ b/packages/opencode/test/release-version.test.ts
@@ -0,0 +1,66 @@
+import { describe, expect, test } from "bun:test"
+import { resolveReleaseVersion } from "../script/release-version"
+
+describe("GraphAgent release versions", () => {
+  test("starts the independent main release line at 1.0.0", () => {
+    expect(resolveReleaseVersion({ branch: "main", tags: [] })).toEqual({
+      channel: "main",
+      version: "1.0.0",
+      tag: "graphagent-v1.0.0",
+      prerelease: false,
+      latest: true,
+    })
+  })
+
+  test("starts dev at 1.0.0-dev.1 and ignores inherited OpenCode tags", () => {
+    expect(
+      resolveReleaseVersion({
+        branch: "dev",
+        tags: ["v1.17.11-main.10", "v0.0.0-202608082302"],
+      }),
+    ).toEqual({
+      channel: "dev",
+      version: "1.0.0-dev.1",
+      tag: "graphagent-v1.0.0-dev.1",
+      prerelease: true,
+      latest: false,
+    })
+  })
+
+  test("increments the dev sequence within the pending stable version", () => {
+    expect(
+      resolveReleaseVersion({
+        branch: "dev",
+        tags: ["graphagent-v1.0.0-dev.1", "graphagent-v1.0.0-dev.3"],
+      }).version,
+    ).toBe("1.0.0-dev.4")
+  })
+
+  test("promotes the pending dev version on main and moves dev to the next patch", () => {
+    expect(resolveReleaseVersion({ branch: "main", tags: ["graphagent-v1.0.0-dev.4"] }).version).toBe("1.0.0")
+    expect(resolveReleaseVersion({ branch: "dev", tags: ["graphagent-v1.0.0"] }).version).toBe("1.0.1-dev.1")
+    expect(
+      resolveReleaseVersion({
+        branch: "main",
+        tags: ["graphagent-v1.0.0", "graphagent-v1.0.1-dev.2"],
+      }).version,
+    ).toBe("1.0.1")
+  })
+
+  test("rejects releases from feature branches", () => {
+    expect(() => resolveReleaseVersion({ branch: "feat/example", tags: [] })).toThrow(
+      "GraphAgent releases require main or dev",
+    )
+  })
+
+  test("wires one resolved version into both the build and GitHub Release", async () => {
+    const workflow = await Bun.file(new URL("../../../.github/workflows/release-fork.yml", import.meta.url)).text()
+
+    expect(workflow).not.toContain("inputs.version")
+    expect(workflow).not.toContain("0.0.0-")
+    expect(workflow).toContain("OPENCODE_CHANNEL: ${{ needs.version.outputs.channel == 'main' && 'latest' || 'dev' }}")
+    expect(workflow).toContain("OPENCODE_VERSION: ${{ needs.version.outputs.version }}")
+    expect(workflow).toContain('gh release create "${{ needs.version.outputs.tag }}"')
+    expect(workflow).toContain("--prerelease --latest=false")
+  })
+})