Second Brain Cloudflare Fork

A fork of Second Brain for deployment to your own Cloudflare account. It retains upstream MCP, REST, dashboard, and Team features, and adds fixed 128-dimensional EmbeddingGemma, Japanese search adjustments, R2 backups, version history, and write protection. The MIT license and upstream copyright notices are preserved.

What this fork provides

• D1 as the source of truth. Memory content, relationships, history, and deletion records live in D1. Vectorize is a derived index that can be rebuilt.
• Fixed 128-dimensional EmbeddingGemma. Do not mix embedding models or dimensions in an existing index. Search adjustments for Japanese text and full-width identifiers are retained.
• Bounded work and storage protection. Write admission, workspace isolation, CAS, held-row isolation, and deletion receipts remain in place. MCP, generation, and nightly work run in the existing Durable Object.
• Optional direct ChatGPT connection. Workers AI is the default. A ChatGPT plan is used only for the owner's personal workspace after the owner connects and enables it. No VPS or CLIProxyAPI is required.

The current upstream base is main at 4e30f973802e54740f7e709516c365078760febb, which merged the upstream 4.0.0 release. Audits now track upstream/main. This remains an independently maintained fork.

Self-hosting

The deployment guide covers account checks, D1, KV, Vectorize, R2, Cloudflare Access, secrets, initialization, and verification.

git clone https://github.com/YOUR_ACCOUNT/YOUR_PUBLIC_FORK.git second-brain
cd second-brain
npm ci --legacy-peer-deps
cp wrangler.jsonc wrangler.personal.jsonc

Replace the URL with the URL of this public fork. wrangler.jsonc is a shared template without resource IDs. Store your resource IDs, Worker name, and owner settings in the ignored wrangler.personal.jsonc. When updating an existing deployment, explicitly select its deployment configuration.

The upstream Deploy button and desktop app target upstream. Use this fork's deployment guide for its 128-dimensional index, Access, and R2 configuration. The installer/ implementation matches upstream, but this fork does not distribute or sign its own installer.

Workers, Durable Objects, Workers AI, D1, KV, Vectorize, and R2 have separate usage allowances. Staying within free allowances is not guaranteed. Check service availability and pricing for your account.

Connecting clients

Connection	URL and authentication
Browser	https://YOUR-WORKER-URL/dashboard. Sign in through owner-only Cloudflare Access.
OAuth-capable MCP client	https://YOUR-WORKER-URL/oauth-mcp. Authenticate through the Worker's OAuth flow. Do not cover this path with an Access application.
Static-token MCP client	https://YOUR-WORKER-URL/mcp. Use Authorization: Bearer <token>. If an Access application also protects this endpoint, its authentication is required too.
REST	Pass the owner token or a supported user token in the Authorization header. Do not put tokens in URLs.

For common client issues, see upstream Connect to AI Clients → Troubleshooting, including Opera warnings, Cursor OAuth, and Claude Code tool visibility. Use the fork-specific endpoints in the table above.

Memory tools

Tool	Purpose
remember	Save opinions, decisions, preferences, and context. Set valid_from when a fact became true and valid_until when it stopped being true.
append	Add a timestamped addition to an existing memory.
rollover	Continue a long journal as a short current-state memory while retaining the original.
update	Update a memory. Set valid_until when a fact stopped being true.
recall	Search semantically. Use as_of to find facts valid on a past date.
brief	Review deadlines, open commitments, stale memories, and unreviewed insights.
resolve	Resolve tracked tasks, dates, insights, and stale facts.
digest	Read an existing automatic summary for a project or tag.
history	Read changes to a memory and the content before each change.
list_recent	List recently saved memories.
list_projects	List projects you can read.
list_teams	List your shared teams and their workspace IDs.
get	Read a memory by ID.
forget	Move a memory to trash. Use undo to restore it.
undo	Undo the most recent change to a memory or restore it from trash.
set_status	Mark a memory as canonical, draft, or deprecated.
set_memory_tier	Change the manual storage tier to hot, warm, or cold. Cold memories remain searchable.
pin_memory	Pin a user-confirmed current goal or constraint to Hot context.
unpin_memory	Remove a manual pin without changing the storage tier.
get_hot_context	Read a bounded set of manually hot or pinned memories.
get_prompt_capsule	Read a deterministic Prompt Capsule and strong ETag through authenticated MCP.
link	Create an explicit relationship between two memories.
unlink	Remove a relationship between memories.
connections	List memories connected to a given memory.
share	Move a memory between personal and shared workspaces.

Fact validity and change history are distinct. as_of finds facts valid at a past time; original content superseded by new facts remains in history. In Team configurations, workspace=personal selects the personal workspace and workspace=company selects the shared workspace. Searches always stay within the caller's readable scope.

Projects

Projects group related memories. Use list_projects to discover available projects, then select a project in supported searches, listings, and summaries. Team membership alone does not grant access to another user's personal workspace.

Development and updates

npm run typecheck
npm test
npm run check:scope
npm run benchmark:validate

See the upstream synchronization guide and ownership boundaries. Keep the 21 upstream-owned files, dependency declarations, lockfile, and installer aligned with upstream.

The dependency security review records current findings, usage conditions, and why upstream dependencies are retained. Success of the report-only CI job does not mean there are no vulnerabilities.

See also direct ChatGPT connection, R2 backup and restore, and the fork documentation index. Keep credentials, real memories, and personal deployment records out of public Git history.