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PopNx MCPMCP servers for people who use AI · explained in plain words

SurStor Memory

by SurStorversion 0.2.0-alpha.3-mcp.1i★ –iRuns on your computer
Registry nameio.github.SurStor/surstor-memory

Install

Overview

Description from the maker (original English)

Local memory for AI models: store, retrieve and verify records on your own hardware.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

  • Connection: Runs on your computer
  • Transport: Streamable HTTP
  • Category: Search & AI memory

Install

Pick the AI app you use, then copy the settings.

Before you install

  • Basic checks: 1 of 1 passed
  • Runs on your computer with your user’s permissions (files, network, apps).
  • The registry lists no key to fill in.

You need

Which app do you use?

Pick your app above. We remember it, so next time the button says “Install in …”.

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "surstor-memory": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "ghcr.io/surstor/surstor-memory:0.2.0-alpha.3-mcp.1"
      ]
    }
  }
}

Run this in your terminal

claude mcp add surstor-memory -- docker run -i --rm ghcr.io/surstor/surstor-memory:0.2.0-alpha.3-mcp.1

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "surstor-memory": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "ghcr.io/surstor/surstor-memory:0.2.0-alpha.3-mcp.1"
      ]
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "surstor-memory": {
      "type": "stdio",
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "ghcr.io/surstor/surstor-memory:0.2.0-alpha.3-mcp.1"
      ]
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 6, 2026

  • ✓ Pass

    Maker matches the repo

    The registry name was verified with the GitHub account SurStor, which owns the repo

  • … Not checked yet

    Still maintained

    We have not read this repo from GitHub yet

  • … Not checked yet

    Has a licence

    We have not read this repo from GitHub yet

  • – Not applicable

    Endpoint responds

    This one runs on your computer; there is no internet endpoint

  • – Not applicable

    Sign-in with OAuth

    Runs on your computer and uses local settings instead

  • … Not checked yet

    No hidden instructions in tool descriptions

    Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Search & AI memoryi

  • More stars than 0% of the other 7223 servers in this category
  • Published to the registry more recently than 84% of the other 7223 servers in this category
  • Basic checks equal to or better than 100% of the other 7223 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is SurStor Memory safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (0.2.0-alpha.3-mcp.1) reached the registry 6 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Docker on your computer.

What can I use instead?

In the same category: Context7, Codebase Memory, Exa

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Context7

by upstash

Feeds AI the latest docs for libraries and frameworks before it answers, so code it writes does not use outdated, removed functions.

Computer or cloud★ 64,224MITUpdated 3 days ago
Install

Codebase Memory

by DeusData

Codebase knowledge graph for AI agents — 162 languages, sub-ms queries, 99% fewer tokens.

Runs on your computer★ 48,148MITUpdated 20 days ago
Install

Exa

by exa-labs

Connect AI agents to Exa for web search, content fetching, and multi-step research.

Runs in the cloud★ 5,213MITUpdated 44 days ago
Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

SurStor Memory — memory for models you run yourself

Website: [www.surstor.net](https://www.surstor.net)

v0.2.0-alpha.3-mcp.1 · Developer Preview

Current install version: 0.2.0-alpha.3-mcp.1, matching the Official MCP Registry listing. This is the MCP packaging revision of the alpha.3 application; the bundled JARs still report 0.2.0-alpha.3. It adds registry ownership metadata without changing application behavior. See release notes.

Early software for testing and feedback. Features and interfaces may change; review the limitations below before storing important information.

Licensed under the Apache License 2.0. Third-party dependencies and bundled assets remain subject to their respective licenses.

Keep project decisions, useful answers and work history on your own hardware, then let your local AI retrieve them across conversations. SurStor Node (v0.2.0-alpha.3) provides persistent, inspectable external memory through MCP. Your model stays in your chosen inference application; SurStor stores and retrieves its memories.

[Start here: install alongside a local model and connect MCP](docs/local-models.md) — includes an LM Studio setup, a save-and-recall example, and Ollama integration requirements. For container packaging, see Run with Docker. Keep using your tools as always.

Local model <-> MCP-capable chat or agent application

| SurStor MCP (localhost:8484) | Local records + optional search index

  • Save approved facts, preferences, decisions and handoff notes as text memories.
  • Find relevant past work through local semantic search, or retrieve by record ID.
  • Inspect provenance, verify record integrity and export sessions for reuse.
  • Reuse the same node with another local model through a compatible MCP host.

SurStor is a single-user node built on Covia venues, Convex lattice and CAD3 content addressing, without running Convex consensus. It binds to 127.0.0.1:8484. It does not train your model, automatically capture every conversation, or automatically resolve conflicting memories. The host must call its tools. Retrieving a few relevant records can avoid repeating entire histories; token savings and answer quality need measurement for your workload.

For a fresh encrypted venue, use the encrypted-storage guide and config/surstor-encrypted.toml. This opt-in profile encrypts Etch records and its index, requires an external key, and disables the separate plaintext semantic search index. Existing configurations do not automatically become encrypted.

Optional multi-node memory sync

This checkout includes opt-in bidirectional sync of selected signed memories between trusted nodes, including relaying through a server. Each node retains its own identity and encryption key. See setup, security and limits. Available in alpha.3, with an optional Docker sync overlay. Whole-venue replication and deletion propagation are not enabled.

What it does

Memory has an evidence trail: you can retrieve the original saved content and check its integrity. A valid signature does not establish that a saved claim is true. Save concise, useful context rather than treating all generated text as fact.

Every AI work artifact (draft, tool result, patch, model output) is stored as a two-cell CAD3 record:

  • Cell 1 — the content, content-addressed (SHA3-256 of canonical encoding)
  • Cell 2 — provenance metadata: branch-ref (Cell 1 hash, the Merkle binding), session ID, agent ID, model version, timestamp, token usage, versioned billing breakdown + estimated cost + cited price schedule, prev-event (session hash chain), and the node's Ed25519 signature over the unsigned cell hash

Sessions form append-only hash chains (prev-event links), so a rewritten or dropped event is detectable. Costs are computed at capture time against a versioned price schedule and frozen into the record — historical artifacts are never repriced. Verification replays the original calculation and schedule.

Cost warning: SurStor estimates API costs from a dated snapshot of public provider prices and caller-supplied usage. These are not provider invoices. Unreported charges, taxes, credits, subscriptions and negotiated discounts are excluded. Unpriced records are excluded from totals and counted separately; legacy sessions may have unknown coverage. Verification proves integrity and arithmetic, not billing accuracy. The session budget is not a provider spending cap.

The September 10, 2026 snapshot covers 31 major OpenAI, Anthropic, Kimi, Gemini, DeepSeek and Grok model entries. New billing supports cache writes, cache storage, tool charges, service tiers, context thresholds and time-dependent rates. See [Billing and pricing documentation](docs/billing.md) for official sources, rates, caller examples, exclusions, migration and verification behavior.

Run with Docker

A public Linux amd64 image is available at ghcr.io/surstor/surstor-memory:0.2.0-alpha.3-mcp.1. From this checkout:

docker compose -f compose.registry.yaml pull

docker compose -f compose.registry.yaml up -d

Connect MCP at http://127.0.0.1:8484/mcp. This default profile uses unencrypted storage with local semantic search. For encrypted storage and backup guidance, see the Docker guide. The container needs no Java or Maven installation on the host. Docker Desktop and ARM64 remain untested.

Build & run

Requires Java 21+ and Maven 3.7+. Covia `0.9.6-SNAPSHOT` is the default installation dependency, configured by covia.version in the root pom.xml. No Maven version override is needed.

Before building SurStor on a fresh machine, build and install a compatible Covia source checkout that produces ai.covia:covia-core:0.9.6-SNAPSHOT and ai.covia:venue:0.9.6-SNAPSHOT into the local Maven repository:

# Run inside the compatible Covia source checkout first.

mvn clean install -DskipTests

Then run the commands below from the SurStor repository root. The snapshot version is the default, but does not identify an immutable upstream revision; record the Covia commit used and run SurStor's tests against that build. See integration notes for dependency compatibility.

Prompt-and-response capture now has a local review screen at /capture, built-in secret detection, organisation exclusions and fail-closed filtering. Only the filtered version is recorded. Automated detection can miss sensitive data; review every field before saving. See [Prompt capture and privacy](docs/prompt-capture.md) for configuration, API usage, compatibility changes and protection limits.

mvn package

java -jar surstor-node/target/surstor-node.jar start --config config/surstor.toml

The example above uses the unencrypted profile. For encrypted installation, follow the encrypted-storage guide. The node persists to ~/.surstor-node/ with the example profile (etch store + Ed25519 identity keypair, auto-generated on first run).

Other commands:

java -jar surstor-node.jar status                 # config, identity, budget

java -jar surstor-node.jar verify # offline verification of an export bundle

MCP operations

All twelve operations are exposed as MCP tools at http://127.0.0.1:8484/mcp (tools/list), plus the venue's built-in tool set:

ToolPurpose
surstor_storeStore an artifact (content, sessionId, agentId, modelVersion, usage)
surstor_retrieveFetch content + full provenance metadata
surstor_verifyCheck branch-ref, session chain (deep), schedule, signature
surstor_listList artifacts, optionally by session
surstor_diffUnified diff between two text artifacts
surstor_costCost rollup for one session or all local sessions
surstor_sessionsList sessions with chain head, counts, totals
surstor_exportExport a session as a portable, offline-verifiable JSON bundle
surstor_prices_getShow the active price schedule
surstor_prices_putInstall a new price schedule (future costs only)
surstor_searchLocal semantic search: ranked artifact IDs + snippets for a natural-language query
surstor_reindexRebuild the search index from the etch store (wipe + replay)

The node binds loopback only; anonymous local callers get full access (auth.public.caps: unrestricted). Loopback limits network exposure, but other local processes can still access the node. Use only trusted clients and keep the bind local. See MCP setup for client configuration.

Tamper evidence

  • Byte-flip a content cell → branchRef check fails
  • Rewrite a middle event → the session head (recorded at capture time) never cites the forgery; the honest chain still verifies
  • Drop an event → deep verify / offline bundle verification reports the chain gap

See docs/tamper-demo.md for a walkthrough. Offline bundles (surstor_export) verify with no venue: surstor-node verify bundle.json recomputes every hash and signature from the file alone (exit 0 = valid).

Tests

mvn test

Tests cover cell/unit semantics, JSON round-trip hash stability, engine-backed tamper scenarios, budget enforcement, real server-restart persistence, versioned billing and tariff boundaries, offline export verification, embedding determinism/similarity, Lucene index behaviour, and engine-backed semantic search (store→search→reindex).

Local semantic search (v0.2.0-alpha.3)

surstor_search ranks stored artifacts by meaning, not just by ID — e.g. "when is the project due" finds the client-deadline email. Everything runs on-node: a bundled multilingual MiniLM model (ONNX, via DJL + ONNX Runtime) embeds text on CPU, and a Lucene HNSW vector index under the data dir answers queries. The embedding/search path makes no external API calls. Retrieved content is returned to the client: keeping inference local also requires a local model and no cloud fallback or external forwarding by the host.

Only string-content records are indexed. Save concise memories as contentType: "text" with a string content; structured prompt/response objects are not semantically indexed. The encrypted-storage profile disables semantic search; use session listing and retrieval by ID instead.

The two-cell CAD3 record remains the only source of truth. Embeddings and the index are derived, unsigned, disposable data: if search-index/ is deleted, surstor_reindex rebuilds it from the etch store with zero information loss. Indexing failure never fails a store.

Config (defaults shown):

[search]

enabled = "true" k_default = "10"

Note: the adapter module jar grows by ~190 MB (ONNX native binaries + bundled model). Accepted for v0.2.

Caveats (v0.2.0-alpha.3)

  • The current price schedule is a dated estimate snapshot, not a live price feed. The original August placeholder file is retained unchanged for historical verification; it is no longer the default. Only an exact match to the old built-in placeholder is automatically upgraded. Custom schedules are preserved.
  • Budget enforcement is per session (session-budget-usd in adapter config, default 5.00)
  • Artifacts stored before signature support was added fail the signature check. Use a separate fresh data directory for a new installation; preserve any existing records you need.
  • Local model identifiers without a matching API tariff remain unpriced, not zero-cost. SurStor does not estimate electricity or hardware costs.
  • Automatic memory supersession, a user-facing deletion workflow, multi-user isolation are not provi

Only the beginning is shown; read the rest in the repo

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