feat: add opencode support

server/modules/providers/list/codex/codex-skills.provider.ts

@@ -1,52 +1,12 @@
-import fs from 'node:fs/promises';
 import os from 'node:os';
 import path from 'node:path';
 
 import { SkillsProvider } from '@/modules/providers/shared/skills/skills.provider.js';
 import type { ProviderSkillSource } from '@/shared/types.js';
-
-const hasGitMarker = async (dirPath: string): Promise<boolean> => {
-  try {
-    const gitMarkerStats = await fs.stat(path.join(dirPath, '.git'));
-    return gitMarkerStats.isDirectory() || gitMarkerStats.isFile();
-  } catch {
-    return false;
-  }
-};
-
-const findTopmostGitRoot = async (startPath: string): Promise<string | null> => {
-  let currentPath = path.resolve(startPath);
-  let topmostGitRoot: string | null = null;
-
-  while (true) {
-    if (await hasGitMarker(currentPath)) {
-      topmostGitRoot = currentPath;
-    }
-
-    const parentPath = path.dirname(currentPath);
-    if (parentPath === currentPath) {
-      break;
-    }
-
-    currentPath = parentPath;
-  }
-
-  return topmostGitRoot;
-};
-
-const addUniqueSource = (
-  sources: ProviderSkillSource[],
-  seenRootDirs: Set<string>,
-  source: ProviderSkillSource,
-): void => {
-  const normalizedRootDir = path.resolve(source.rootDir);
-  if (seenRootDirs.has(normalizedRootDir)) {
-    return;
-  }
-
-  seenRootDirs.add(normalizedRootDir);
-  sources.push({ ...source, rootDir: normalizedRootDir });
-};
+import {
+  addUniqueProviderSkillSource,
+  findTopmostGitRoot,
+} from '@/shared/utils.js';
 
 export class CodexSkillsProvider extends SkillsProvider {
   constructor() {
@@ -58,7 +18,7 @@ export class CodexSkillsProvider extends SkillsProvider {
     const seenRootDirs = new Set<string>();
     const repoRoot = await findTopmostGitRoot(workspacePath);
 
-    addUniqueSource(sources, seenRootDirs, {
+    addUniqueProviderSkillSource(sources, seenRootDirs, {
       scope: 'repo',
       rootDir: path.join(workspacePath, '.agents', 'skills'),
       commandPrefix: '$',
@@ -67,29 +27,29 @@ export class CodexSkillsProvider extends SkillsProvider {
     if (repoRoot) {
       // Codex checks repository skills at the launch folder, one folder above it,
       // and the topmost git root; these can collapse to the same directory.
-      addUniqueSource(sources, seenRootDirs, {
+      addUniqueProviderSkillSource(sources, seenRootDirs, {
         scope: 'repo',
         rootDir: path.join(path.dirname(workspacePath), '.agents', 'skills'),
         commandPrefix: '$',
       });
-      addUniqueSource(sources, seenRootDirs, {
+      addUniqueProviderSkillSource(sources, seenRootDirs, {
         scope: 'repo',
         rootDir: path.join(repoRoot, '.agents', 'skills'),
         commandPrefix: '$',
       });
     }
 
-    addUniqueSource(sources, seenRootDirs, {
+    addUniqueProviderSkillSource(sources, seenRootDirs, {
       scope: 'user',
       rootDir: path.join(os.homedir(), '.agents', 'skills'),
       commandPrefix: '$',
     });
-    addUniqueSource(sources, seenRootDirs, {
+    addUniqueProviderSkillSource(sources, seenRootDirs, {
       scope: 'admin',
       rootDir: path.join('/etc', 'codex', 'skills'),
       commandPrefix: '$',
     });
-    addUniqueSource(sources, seenRootDirs, {
+    addUniqueProviderSkillSource(sources, seenRootDirs, {
       scope: 'system',
       rootDir: path.join(os.homedir(), '.codex', 'skills', '.system'),
       commandPrefix: '$',

server/modules/providers/list/opencode/opencode-auth.provider.ts

@@ -0,0 +1,111 @@
+import { readFile } from 'node:fs/promises';
+import os from 'node:os';
+import path from 'node:path';
+
+import spawn from 'cross-spawn';
+
+import type { IProviderAuth } from '@/shared/interfaces.js';
+import type { ProviderAuthStatus } from '@/shared/types.js';
+import { readObjectRecord, readOptionalString } from '@/shared/utils.js';
+
+type OpenCodeCredentialsStatus = {
+  authenticated: boolean;
+  email: string | null;
+  method: string | null;
+  error?: string;
+};
+
+const OPENCODE_ENV_CREDENTIAL_KEYS = [
+  'ANTHROPIC_API_KEY',
+  'OPENAI_API_KEY',
+  'GOOGLE_GENERATIVE_AI_API_KEY',
+  'GEMINI_API_KEY',
+  'GROQ_API_KEY',
+  'OPENROUTER_API_KEY',
+];
+
+export class OpenCodeProviderAuth implements IProviderAuth {
+  /**
+   * Checks whether the OpenCode CLI is available to the server process.
+   */
+  private checkInstalled(): boolean {
+    try {
+      const result = spawn.sync('opencode', ['--version'], { stdio: 'ignore', timeout: 5000 });
+      return !result.error && result.status === 0;
+    } catch {
+      return false;
+    }
+  }
+
+  /**
+   * Returns OpenCode CLI installation and credential status.
+   */
+  async getStatus(): Promise<ProviderAuthStatus> {
+    const installed = this.checkInstalled();
+    const credentials = await this.checkCredentials();
+
+    return {
+      installed,
+      provider: 'opencode',
+      authenticated: credentials.authenticated,
+      email: credentials.email,
+      method: credentials.method,
+      error: credentials.authenticated ? undefined : credentials.error || 'Not authenticated',
+    };
+  }
+
+  /**
+   * Reads OpenCode's auth store or falls back to provider API key environment variables.
+   */
+  private async checkCredentials(): Promise<OpenCodeCredentialsStatus> {
+    try {
+      const authPath = path.join(os.homedir(), '.local', 'share', 'opencode', 'auth.json');
+      const content = await readFile(authPath, 'utf8');
+      const auth = readObjectRecord(JSON.parse(content)) ?? {};
+
+      for (const [providerId, providerAuth] of Object.entries(auth)) {
+        const providerRecord = readObjectRecord(providerAuth);
+        if (!providerRecord) {
+          continue;
+        }
+
+        const hasCredential = Object.values(providerRecord).some(
+          (value) => readOptionalString(value) !== undefined || Boolean(readObjectRecord(value)),
+        );
+        if (hasCredential) {
+          return {
+            authenticated: true,
+            email: `${providerId} credentials`,
+            method: 'credentials_file',
+          };
+        }
+      }
+    } catch (error) {
+      const code = (error as NodeJS.ErrnoException).code;
+      if (code !== 'ENOENT') {
+        return {
+          authenticated: false,
+          email: null,
+          method: null,
+          error: error instanceof Error ? error.message : 'Failed to read OpenCode auth',
+        };
+      }
+    }
+
+    const envCredential = OPENCODE_ENV_CREDENTIAL_KEYS.find((key) => process.env[key]?.trim());
+    if (envCredential) {
+      return {
+        authenticated: true,
+        email: envCredential,
+        method: 'environment',
+      };
+    }
+
+    return {
+      authenticated: false,
+      email: null,
+      method: null,
+      error: 'OpenCode not configured',
+    };
+  }
+}

server/modules/providers/list/opencode/opencode-mcp.provider.ts

@@ -0,0 +1,228 @@
+import { access, mkdir, readFile, writeFile } from 'node:fs/promises';
+import os from 'node:os';
+import path from 'node:path';
+
+import { McpProvider } from '@/modules/providers/shared/mcp/mcp.provider.js';
+import type { McpScope, ProviderMcpServer, UpsertProviderMcpServerInput } from '@/shared/types.js';
+import {
+  AppError,
+  readObjectRecord,
+  readOptionalString,
+  readStringArray,
+  readStringRecord,
+} from '@/shared/utils.js';
+
+type OpenCodeConfigPath = {
+  filePath: string;
+  exists: boolean;
+};
+
+const fileExists = async (filePath: string): Promise<boolean> => {
+  try {
+    await access(filePath);
+    return true;
+  } catch {
+    return false;
+  }
+};
+
+/**
+ * Removes JSONC comments without touching comment-like text inside strings.
+ */
+const stripJsonComments = (content: string): string => {
+  let output = '';
+  let inString = false;
+  let quote = '';
+  let escaped = false;
+
+  for (let index = 0; index < content.length; index += 1) {
+    const char = content[index];
+    const next = content[index + 1];
+
+    if (inString) {
+      output += char;
+      if (escaped) {
+        escaped = false;
+      } else if (char === '\\') {
+        escaped = true;
+      } else if (char === quote) {
+        inString = false;
+        quote = '';
+      }
+      continue;
+    }
+
+    if (char === '"' || char === '\'') {
+      inString = true;
+      quote = char;
+      output += char;
+      continue;
+    }
+
+    if (char === '/' && next === '/') {
+      while (index < content.length && content[index] !== '\n') {
+        index += 1;
+      }
+      output += '\n';
+      continue;
+    }
+
+    if (char === '/' && next === '*') {
+      index += 2;
+      while (index < content.length && !(content[index] === '*' && content[index + 1] === '/')) {
+        index += 1;
+      }
+      index += 1;
+      continue;
+    }
+
+    output += char;
+  }
+
+  return output;
+};
+
+const stripTrailingCommas = (content: string): string =>
+  content.replace(/,\s*([}\]])/g, '$1');
+
+const readOpenCodeConfig = async (filePath: string): Promise<Record<string, unknown>> => {
+  try {
+    const content = await readFile(filePath, 'utf8');
+    const parsed = JSON.parse(stripTrailingCommas(stripJsonComments(content))) as unknown;
+    return readObjectRecord(parsed) ?? {};
+  } catch (error) {
+    const code = (error as NodeJS.ErrnoException).code;
+    if (code === 'ENOENT') {
+      return {};
+    }
+
+    throw error;
+  }
+};
+
+const writeOpenCodeConfig = async (filePath: string, data: Record<string, unknown>): Promise<void> => {
+  await mkdir(path.dirname(filePath), { recursive: true });
+  await writeFile(filePath, `${JSON.stringify(data, null, 2)}\n`, 'utf8');
+};
+
+const resolveOpenCodeConfigPath = async (scope: McpScope, workspacePath: string): Promise<OpenCodeConfigPath> => {
+  const root = scope === 'user'
+    ? path.join(os.homedir(), '.config', 'opencode')
+    : workspacePath;
+  const jsonPath = path.join(root, 'opencode.json');
+  const jsoncPath = path.join(root, 'opencode.jsonc');
+
+  if (await fileExists(jsonPath)) {
+    return { filePath: jsonPath, exists: true };
+  }
+
+  if (await fileExists(jsoncPath)) {
+    return { filePath: jsoncPath, exists: true };
+  }
+
+  return { filePath: jsonPath, exists: false };
+};
+
+export class OpenCodeMcpProvider extends McpProvider {
+  constructor() {
+    super('opencode', ['user', 'project'], ['stdio', 'http']);
+  }
+
+  protected async readScopedServers(scope: McpScope, workspacePath: string): Promise<Record<string, unknown>> {
+    const { filePath } = await resolveOpenCodeConfigPath(scope, workspacePath);
+    const config = await readOpenCodeConfig(filePath);
+    return readObjectRecord(config.mcp) ?? {};
+  }
+
+  protected async writeScopedServers(
+    scope: McpScope,
+    workspacePath: string,
+    servers: Record<string, unknown>,
+  ): Promise<void> {
+    const { filePath } = await resolveOpenCodeConfigPath(scope, workspacePath);
+    const config = await readOpenCodeConfig(filePath);
+    config.mcp = servers;
+    await writeOpenCodeConfig(filePath, config);
+  }
+
+  protected buildServerConfig(input: UpsertProviderMcpServerInput): Record<string, unknown> {
+    if (input.transport === 'stdio') {
+      if (!input.command?.trim()) {
+        throw new AppError('command is required for stdio MCP servers.', {
+          code: 'MCP_COMMAND_REQUIRED',
+          statusCode: 400,
+        });
+      }
+
+      return {
+        type: 'local',
+        command: [input.command, ...(input.args ?? [])],
+        enabled: true,
+        environment: input.env ?? {},
+      };
+    }
+
+    if (!input.url?.trim()) {
+      throw new AppError('url is required for http MCP servers.', {
+        code: 'MCP_URL_REQUIRED',
+        statusCode: 400,
+      });
+    }
+
+    return {
+      type: 'remote',
+      url: input.url,
+      enabled: true,
+      headers: input.headers ?? {},
+    };
+  }
+
+  protected normalizeServerConfig(
+    scope: McpScope,
+    name: string,
+    rawConfig: unknown,
+  ): ProviderMcpServer | null {
+    const config = readObjectRecord(rawConfig);
+    if (!config) {
+      return null;
+    }
+
+    if (config.type === 'local' || config.command !== undefined) {
+      const commandParts = typeof config.command === 'string'
+        ? [config.command, ...(readStringArray(config.args) ?? [])]
+        : readStringArray(config.command);
+      const command = commandParts?.[0];
+      if (!command) {
+        return null;
+      }
+
+      return {
+        provider: 'opencode',
+        name,
+        scope,
+        transport: 'stdio',
+        command,
+        args: commandParts.slice(1),
+        env: readStringRecord(config.environment) ?? readStringRecord(config.env),
+      };
+    }
+
+    if (config.type === 'remote' || typeof config.url === 'string') {
+      const url = readOptionalString(config.url);
+      if (!url) {
+        return null;
+      }
+
+      return {
+        provider: 'opencode',
+        name,
+        scope,
+        transport: 'http',
+        url,
+        headers: readStringRecord(config.headers),
+      };
+    }
+
+    return null;
+  }
+}

server/modules/providers/list/opencode/opencode-session-synchronizer.provider.ts

@@ -0,0 +1,157 @@
+import fsSync from 'node:fs';
+import path from 'node:path';
+
+import Database from 'better-sqlite3';
+
+import { sessionsDb } from '@/modules/database/index.js';
+import type { IProviderSessionSynchronizer } from '@/shared/interfaces.js';
+import {
+  getOpenCodeDatabasePath,
+  normalizeProviderTimestamp,
+  normalizeSessionName,
+  readJsonRecord,
+  readOptionalString,
+} from '@/shared/utils.js';
+
+type OpenCodeSessionRow = {
+  id: string;
+  directory: string | null;
+  title: string | null;
+  time_created: number | null;
+  time_updated: number | null;
+  worktree: string | null;
+};
+
+type SynchronizeRowsResult = {
+  processed: number;
+  firstSessionId: string | null;
+};
+
+/**
+ * Session indexer for OpenCode's SQLite-backed session store.
+ */
+export class OpenCodeSessionSynchronizer implements IProviderSessionSynchronizer {
+  private readonly provider = 'opencode' as const;
+
+  /**
+   * Scans OpenCode's shared opencode.db and upserts active sessions into DB.
+   */
+  async synchronize(since?: Date): Promise<number> {
+    const result = this.synchronizeRows(since);
+    return result.processed;
+  }
+
+  /**
+   * Handles watcher changes for opencode.db.
+   */
+  async synchronizeFile(filePath: string): Promise<string | null> {
+    if (path.basename(filePath) !== 'opencode.db') {
+      return null;
+    }
+
+    const result = this.synchronizeRows(undefined, 1);
+    return result.firstSessionId;
+  }
+
+  private synchronizeRows(since?: Date, limit?: number): SynchronizeRowsResult {
+    const dbPath = getOpenCodeDatabasePath();
+    if (!fsSync.existsSync(dbPath)) {
+      return { processed: 0, firstSessionId: null };
+    }
+
+    const db = new Database(dbPath, { readonly: true, fileMustExist: true });
+    try {
+      const sinceMillis = since?.getTime() ?? null;
+      const limitClause = limit ? 'LIMIT ?' : '';
+      const params = limit ? [sinceMillis, sinceMillis, limit] : [sinceMillis, sinceMillis];
+      const rows = db.prepare(`
+        SELECT
+          s.id AS id,
+          s.directory AS directory,
+          s.title AS title,
+          s.time_created AS time_created,
+          s.time_updated AS time_updated,
+          p.worktree AS worktree
+        FROM session s
+        LEFT JOIN project p ON p.id = s.project_id
+        WHERE s.time_archived IS NULL
+          AND (? IS NULL OR COALESCE(s.time_updated, s.time_created, 0) >= ?)
+        ORDER BY COALESCE(s.time_updated, s.time_created, 0) DESC, s.id DESC
+        ${limitClause}
+      `).all(...params) as OpenCodeSessionRow[];
+
+      let processed = 0;
+      let firstSessionId: string | null = null;
+      for (const row of rows) {
+        const indexedSessionId = this.upsertSession(db, row);
+        if (!indexedSessionId) {
+          continue;
+        }
+
+        if (!firstSessionId) {
+          firstSessionId = indexedSessionId;
+        }
+        processed += 1;
+      }
+
+      return { processed, firstSessionId };
+    } catch (error) {
+      const message = error instanceof Error ? error.message : String(error);
+      console.warn('[OpenCodeProvider] Failed to synchronize sessions:', message);
+      return { processed: 0, firstSessionId: null };
+    } finally {
+      db.close();
+    }
+  }
+
+  private upsertSession(db: Database.Database, row: OpenCodeSessionRow): string | null {
+    const sessionId = readOptionalString(row.id);
+    const projectPath = readOptionalString(row.directory) ?? readOptionalString(row.worktree);
+    if (!sessionId || !projectPath) {
+      return null;
+    }
+
+    const fallbackTitle = 'Untitled OpenCode Session';
+    const existingSession = sessionsDb.getSessionById(sessionId);
+    const existingName = existingSession?.custom_name;
+    const nextName = existingName && existingName !== fallbackTitle
+      ? existingName
+      : readOptionalString(row.title) ?? this.readFirstUserText(db, sessionId);
+
+    // OpenCode stores every session in one shared sqlite database, so jsonl_path
+    // must stay null to avoid deleting opencode.db when one app session is removed.
+    sessionsDb.createSession(
+      sessionId,
+      this.provider,
+      projectPath,
+      normalizeSessionName(nextName, fallbackTitle),
+      normalizeProviderTimestamp(row.time_created),
+      normalizeProviderTimestamp(row.time_updated ?? row.time_created),
+      null,
+    );
+
+    return sessionId;
+  }
+
+  private readFirstUserText(db: Database.Database, sessionId: string): string | undefined {
+    try {
+      const row = db.prepare(`
+        SELECT p.data AS data
+        FROM message m
+        INNER JOIN part p
+          ON p.session_id = m.session_id
+         AND p.message_id = m.id
+        WHERE m.session_id = ?
+          AND json_extract(m.data, '$.role') = 'user'
+          AND json_extract(p.data, '$.type') = 'text'
+        ORDER BY COALESCE(m.time_created, 0), COALESCE(p.time_created, 0)
+        LIMIT 1
+      `).get(sessionId) as { data: string | null } | undefined;
+
+      const data = readJsonRecord(row?.data);
+      return readOptionalString(data?.text);
+    } catch {
+      return undefined;
+    }
+  }
+}

server/modules/providers/list/opencode/opencode-sessions.provider.ts

@@ -0,0 +1,426 @@
+import fsSync from 'node:fs';
+
+import Database from 'better-sqlite3';
+
+import type { IProviderSessions } from '@/shared/interfaces.js';
+import type { AnyRecord, FetchHistoryOptions, FetchHistoryResult, NormalizedMessage } from '@/shared/types.js';
+import {
+  createNormalizedMessage,
+  generateMessageId,
+  getOpenCodeDatabasePath,
+  normalizeProviderTimestamp,
+  readObjectRecord,
+  readJsonRecord,
+  readOptionalString,
+} from '@/shared/utils.js';
+
+const PROVIDER = 'opencode';
+
+type OpenCodeHistoryRow = {
+  message_id: string;
+  message_time_created: number | null;
+  message_data: string | null;
+  part_id: string | null;
+  part_time_created: number | null;
+  part_data: string | null;
+};
+
+type OpenCodeTokenTotals = {
+  inputTokens: number;
+  outputTokens: number;
+  cacheReadTokens: number;
+  cacheCreationTokens: number;
+  reasoningTokens: number;
+};
+
+const openOpenCodeDatabase = (): Database.Database | null => {
+  const dbPath = getOpenCodeDatabasePath();
+  if (!fsSync.existsSync(dbPath)) {
+    return null;
+  }
+
+  return new Database(dbPath, { readonly: true, fileMustExist: true });
+};
+
+const formatToolContent = (value: unknown): string => {
+  if (value === undefined || value === null) {
+    return '';
+  }
+
+  if (typeof value === 'string') {
+    return value;
+  }
+
+  try {
+    return JSON.stringify(value, null, 2);
+  } catch {
+    return String(value);
+  }
+};
+
+const extractText = (value: unknown): string => {
+  if (typeof value === 'string') {
+    return value;
+  }
+
+  const record = readObjectRecord(value);
+  return readOptionalString(record?.text)
+    ?? readOptionalString(record?.content)
+    ?? '';
+};
+
+const buildTokenUsage = (totals: OpenCodeTokenTotals | undefined): AnyRecord | undefined => {
+  if (!totals) {
+    return undefined;
+  }
+
+  const inputTokens = totals.inputTokens;
+  const outputTokens = totals.outputTokens;
+  const cacheReadTokens = totals.cacheReadTokens;
+  const cacheCreationTokens = totals.cacheCreationTokens;
+  const reasoningTokens = totals.reasoningTokens;
+  const used = inputTokens + outputTokens + cacheReadTokens + cacheCreationTokens + reasoningTokens;
+
+  if (used <= 0) {
+    return undefined;
+  }
+
+  return {
+    used,
+    total: used,
+    inputTokens,
+    outputTokens,
+    cacheReadTokens,
+    cacheCreationTokens,
+  };
+};
+
+/**
+ * OpenCode stores per-message token counts on assistant `message.data` objects
+ * (see MessageV2.Assistant). Older DBs also had session-level counters; this
+ * matches current `opencode.db` layouts that only persist message JSON.
+ */
+const aggregateOpenCodeSessionTokenUsage = (
+  db: Database.Database,
+  sessionId: string,
+): AnyRecord | undefined => {
+  const rows = db.prepare('SELECT data FROM message WHERE session_id = ?').all(sessionId) as { data: string }[];
+
+  let inputTokens = 0;
+  let outputTokens = 0;
+  let cacheReadTokens = 0;
+  let cacheCreationTokens = 0;
+  let reasoningTokens = 0;
+
+  for (const row of rows) {
+    const info = readJsonRecord(row.data);
+    if (readOptionalString(info?.role) !== 'assistant') {
+      continue;
+    }
+
+    const tokens = readObjectRecord(info?.tokens);
+    if (!tokens) {
+      continue;
+    }
+
+    inputTokens += Number(tokens.input ?? 0);
+    outputTokens += Number(tokens.output ?? 0);
+    reasoningTokens += Number(tokens.reasoning ?? 0);
+    const cache = readObjectRecord(tokens.cache);
+    cacheReadTokens += Number(cache?.read ?? 0);
+    cacheCreationTokens += Number(cache?.write ?? 0);
+  }
+
+  return buildTokenUsage({
+    inputTokens,
+    outputTokens,
+    cacheReadTokens,
+    cacheCreationTokens,
+    reasoningTokens,
+  });
+};
+
+export class OpenCodeSessionsProvider implements IProviderSessions {
+  /**
+   * Normalizes live `opencode run --format json` events into frontend messages.
+   */
+  normalizeMessage(rawMessage: unknown, sessionId: string | null): NormalizedMessage[] {
+    const raw = readObjectRecord(rawMessage);
+    if (!raw) {
+      return [];
+    }
+
+    const type = readOptionalString(raw.type) ?? readOptionalString(raw.event);
+    const eventSessionId = readOptionalString(raw.sessionID) ?? readOptionalString(raw.sessionId) ?? sessionId;
+    const timestamp = normalizeProviderTimestamp(raw.time ?? raw.timestamp);
+    const baseId = readOptionalString(raw.id)
+      ?? readOptionalString(raw.messageID)
+      ?? generateMessageId('opencode');
+
+    if (type === 'text') {
+      const content = extractText(raw.text ?? raw.delta ?? raw.message);
+      if (!content.trim()) {
+        return [];
+      }
+
+      return [createNormalizedMessage({
+        id: baseId,
+        sessionId: eventSessionId,
+        timestamp,
+        provider: PROVIDER,
+        kind: 'stream_delta',
+        content,
+      })];
+    }
+
+    if (type === 'reasoning') {
+      const content = extractText(raw.text ?? raw.delta ?? raw.message);
+      if (!content.trim()) {
+        return [];
+      }
+
+      return [createNormalizedMessage({
+        id: baseId,
+        sessionId: eventSessionId,
+        timestamp,
+        provider: PROVIDER,
+        kind: 'thinking',
+        content,
+      })];
+    }
+
+    if (type === 'tool_use') {
+      const toolName = readOptionalString(raw.tool) ?? readOptionalString(raw.name) ?? 'Tool';
+      const toolId = readOptionalString(raw.callID) ?? readOptionalString(raw.toolCallId) ?? baseId;
+      const toolMessage = createNormalizedMessage({
+        id: baseId,
+        sessionId: eventSessionId,
+        timestamp,
+        provider: PROVIDER,
+        kind: 'tool_use',
+        toolName,
+        toolInput: raw.input ?? raw.arguments ?? {},
+        toolId,
+      });
+
+      if (raw.output !== undefined || raw.error !== undefined) {
+        toolMessage.toolResult = {
+          content: formatToolContent(raw.output ?? raw.error),
+          isError: raw.error !== undefined,
+        };
+      }
+
+      return [toolMessage];
+    }
+
+    if (type === 'error') {
+      return [createNormalizedMessage({
+        id: baseId,
+        sessionId: eventSessionId,
+        timestamp,
+        provider: PROVIDER,
+        kind: 'error',
+        content: readOptionalString(raw.error) ?? readOptionalString(raw.message) ?? 'Unknown OpenCode error',
+      })];
+    }
+
+    if (type === 'step_finish') {
+      return [createNormalizedMessage({
+        id: baseId,
+        sessionId: eventSessionId,
+        timestamp,
+        provider: PROVIDER,
+        kind: 'stream_end',
+      })];
+    }
+
+    return [];
+  }
+
+  /**
+   * Loads OpenCode history from the shared SQLite session database.
+   */
+  async fetchHistory(
+    sessionId: string,
+    options: FetchHistoryOptions = {},
+  ): Promise<FetchHistoryResult> {
+    const { limit = null, offset = 0 } = options;
+    const db = openOpenCodeDatabase();
+    if (!db) {
+      return { messages: [], total: 0, hasMore: false, offset: 0, limit: null };
+    }
+
+    try {
+      const rows = db.prepare(`
+        SELECT
+          m.id AS message_id,
+          m.time_created AS message_time_created,
+          m.data AS message_data,
+          p.id AS part_id,
+          p.time_created AS part_time_created,
+          p.data AS part_data
+        FROM message m
+        LEFT JOIN part p
+          ON p.session_id = m.session_id
+         AND p.message_id = m.id
+        WHERE m.session_id = ?
+        ORDER BY
+          COALESCE(m.time_created, 0),
+          m.id,
+          COALESCE(p.time_created, 0),
+          p.id
+      `).all(sessionId) as OpenCodeHistoryRow[];
+
+      const normalized = this.normalizeHistoryRows(rows, sessionId);
+      const tokenUsage = aggregateOpenCodeSessionTokenUsage(db, sessionId);
+
+      const normalizedOffset = Math.max(0, offset);
+      const normalizedLimit = limit === null ? null : Math.max(0, limit);
+      const total = normalized.length;
+      const messages = normalizedLimit === null
+        ? normalized
+        : normalized.slice(
+            Math.max(0, total - normalizedOffset - normalizedLimit),
+            Math.max(0, total - normalizedOffset),
+          );
+
+      return {
+        messages,
+        total,
+        hasMore: normalizedLimit === null
+          ? false
+          : Math.max(0, total - normalizedOffset - normalizedLimit) > 0,
+        offset: normalizedOffset,
+        limit: normalizedLimit,
+        tokenUsage,
+      };
+    } catch (error) {
+      const message = error instanceof Error ? error.message : String(error);
+      console.warn(`[OpenCodeProvider] Failed to load session ${sessionId}:`, message);
+      return { messages: [], total: 0, hasMore: false, offset: 0, limit: null };
+    } finally {
+      db.close();
+    }
+  }
+
+  private normalizeHistoryRows(rows: OpenCodeHistoryRow[], sessionId: string): NormalizedMessage[] {
+    const normalized: NormalizedMessage[] = [];
+    const emittedMessageErrors = new Set<string>();
+
+    for (const row of rows) {
+      const timestamp = normalizeProviderTimestamp(row.part_time_created ?? row.message_time_created);
+      const baseId = `${row.message_id}_${row.part_id ?? normalized.length}`;
+      const messageInfo = readJsonRecord(row.message_data);
+      const messageRole = readOptionalString(messageInfo?.role);
+
+      if (
+        messageInfo
+        && messageRole === 'assistant'
+        && messageInfo.error != null
+        && !emittedMessageErrors.has(row.message_id)
+      ) {
+        emittedMessageErrors.add(row.message_id);
+        normalized.push(createNormalizedMessage({
+          id: `${baseId}_error`,
+          sessionId,
+          timestamp,
+          provider: PROVIDER,
+          kind: 'error',
+          content: formatToolContent(messageInfo.error),
+        }));
+      }
+
+      if (!row.part_id) {
+        continue;
+      }
+
+      const partData = readJsonRecord(row.part_data) ?? {};
+      const partType = readOptionalString(partData.type);
+      if (!partType) {
+        continue;
+      }
+
+      if (partType === 'text') {
+        const content = extractText(partData);
+        if (content.trim()) {
+          normalized.push(createNormalizedMessage({
+            id: baseId,
+            sessionId,
+            timestamp,
+            provider: PROVIDER,
+            kind: 'text',
+            role: messageRole === 'user' ? 'user' : 'assistant',
+            content,
+          }));
+        }
+        continue;
+      }
+
+      if (partType === 'reasoning') {
+        const content = extractText(partData);
+        if (content.trim()) {
+          normalized.push(createNormalizedMessage({
+            id: baseId,
+            sessionId,
+            timestamp,
+            provider: PROVIDER,
+            kind: 'thinking',
+            content,
+          }));
+        }
+        continue;
+      }
+
+      if (partType === 'tool') {
+        const state = readObjectRecord(partData.state) ?? {};
+        const status = readOptionalString(state.status);
+        const toolMessage = createNormalizedMessage({
+          id: baseId,
+          sessionId,
+          timestamp,
+          provider: PROVIDER,
+          kind: 'tool_use',
+          toolName: readOptionalString(partData.tool) ?? 'Tool',
+          toolInput: state.input ?? partData.input ?? {},
+          toolId: readOptionalString(partData.callID) ?? row.part_id,
+        });
+
+        if (status === 'completed' || status === 'error') {
+          toolMessage.toolResult = {
+            content: formatToolContent(state.output ?? state.error),
+            isError: status === 'error',
+          };
+        }
+
+        normalized.push(toolMessage);
+        continue;
+      }
+
+      if (partType === 'step-finish') {
+        normalized.push(createNormalizedMessage({
+          id: baseId,
+          sessionId,
+          timestamp,
+          provider: PROVIDER,
+          kind: 'stream_end',
+        }));
+        continue;
+      }
+
+      if (partType === 'patch' || partType === 'agent') {
+        normalized.push(createNormalizedMessage({
+          id: baseId,
+          sessionId,
+          timestamp,
+          provider: PROVIDER,
+          kind: 'tool_use',
+          toolName: partType === 'patch' ? 'Patch' : 'Agent',
+          toolInput: partData,
+          toolId: row.part_id,
+        }));
+      }
+    }
+
+    return normalized;
+  }
+}

server/modules/providers/list/opencode/opencode-skills.provider.ts

@@ -0,0 +1,78 @@
+import os from 'node:os';
+import path from 'node:path';
+
+import { SkillsProvider } from '@/modules/providers/shared/skills/skills.provider.js';
+import type { ProviderSkillSource } from '@/shared/types.js';
+import {
+  addUniqueProviderSkillSource,
+  findTopmostGitRoot,
+} from '@/shared/utils.js';
+
+const OPENCODE_PROJECT_SKILL_DIRS = [
+  ['.opencode', 'skills'],
+  ['.claude', 'skills'],
+  ['.agents', 'skills'],
+];
+
+const OPENCODE_USER_SKILL_DIRS = [
+  ['.config', 'opencode', 'skills'],
+  ['.claude', 'skills'],
+  ['.agents', 'skills'],
+];
+
+export class OpenCodeSkillsProvider extends SkillsProvider {
+  constructor() {
+    super('opencode');
+  }
+
+  protected async getSkillSources(workspacePath: string): Promise<ProviderSkillSource[]> {
+    const sources: ProviderSkillSource[] = [];
+    const seenRootDirs = new Set<string>();
+    const repoRoot = await findTopmostGitRoot(workspacePath);
+
+    for (const projectRoot of this.getProjectSearchRoots(workspacePath, repoRoot)) {
+      for (const skillDir of OPENCODE_PROJECT_SKILL_DIRS) {
+        // OpenCode intentionally reads Claude and Agents skill folders so users
+        // can reuse the same skill libraries across compatible coding agents.
+        addUniqueProviderSkillSource(sources, seenRootDirs, {
+          scope: 'project',
+          rootDir: path.join(projectRoot, ...skillDir),
+          commandPrefix: '/',
+        });
+      }
+    }
+
+    for (const skillDir of OPENCODE_USER_SKILL_DIRS) {
+      addUniqueProviderSkillSource(sources, seenRootDirs, {
+        scope: 'user',
+        rootDir: path.join(os.homedir(), ...skillDir),
+        commandPrefix: '/',
+      });
+    }
+
+    return sources;
+  }
+
+  private getProjectSearchRoots(workspacePath: string, repoRoot: string | null): string[] {
+    const roots: string[] = [];
+    const normalizedWorkspacePath = path.resolve(workspacePath);
+    const normalizedRepoRoot = repoRoot ? path.resolve(repoRoot) : null;
+    let currentPath = normalizedWorkspacePath;
+
+    while (true) {
+      roots.push(currentPath);
+      if (!normalizedRepoRoot || currentPath === normalizedRepoRoot) {
+        break;
+      }
+
+      const parentPath = path.dirname(currentPath);
+      if (parentPath === currentPath) {
+        break;
+      }
+
+      currentPath = parentPath;
+    }
+
+    return roots;
+  }
+}

server/modules/providers/list/opencode/opencode.provider.ts

@@ -0,0 +1,24 @@
+import { OpenCodeProviderAuth } from '@/modules/providers/list/opencode/opencode-auth.provider.js';
+import { OpenCodeMcpProvider } from '@/modules/providers/list/opencode/opencode-mcp.provider.js';
+import { OpenCodeSessionSynchronizer } from '@/modules/providers/list/opencode/opencode-session-synchronizer.provider.js';
+import { OpenCodeSessionsProvider } from '@/modules/providers/list/opencode/opencode-sessions.provider.js';
+import { OpenCodeSkillsProvider } from '@/modules/providers/list/opencode/opencode-skills.provider.js';
+import { AbstractProvider } from '@/modules/providers/shared/base/abstract.provider.js';
+import type {
+  IProviderAuth,
+  IProviderSessionSynchronizer,
+  IProviderSkills,
+  IProviderSessions,
+} from '@/shared/interfaces.js';
+
+export class OpenCodeProvider extends AbstractProvider {
+  readonly mcp = new OpenCodeMcpProvider();
+  readonly auth: IProviderAuth = new OpenCodeProviderAuth();
+  readonly skills: IProviderSkills = new OpenCodeSkillsProvider();
+  readonly sessions: IProviderSessions = new OpenCodeSessionsProvider();
+  readonly sessionSynchronizer: IProviderSessionSynchronizer = new OpenCodeSessionSynchronizer();
+
+  constructor() {
+    super('opencode');
+  }
+}