Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add mongodb-partners/mongodb-gemini-extension --skill save_chatgit clone --depth 1 https://github.com/mongodb-partners/mongodb-gemini-extensionWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/mongodb-partners/mongodb-gemini-extension/save_chat)<a href="https://agentmods.dev/skills/mongodb-partners/mongodb-gemini-extension/save_chat"><img src="https://agentmods.dev/badge/skills/mongodb-partners/mongodb-gemini-extension/save_chat/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/mongodb-partners/mongodb-gemini-extension/save_chat"><img src="https://agentmods.dev/badge/skills/mongodb-partners/mongodb-gemini-extension/save_chat.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00014 | $0.00404 |
| Opus 5.5 | $0.00006 | $0.00162 |
| Sonnet 5.5 | $0.00003 | $0.00081 |
| Haiku 4.5 | $0.00001 | $0.00040 |
Grade A, and why
Memory Extension scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
Gemini CLI: MongoDB Agentic Memory Extension
This extension provides a persistent memory layer for the Gemini CLI using MongoDB Atlas. It enables the AI to "remember" previous interactions, user preferences, and project-specific context across different terminal sessions.
Workflow
- Session Persistence: Maintains a sliding window of the last 20 interactions for immediate context.
- Semantic Long-Term Memory: Uses MongoDB Atlas Vector Search to recall relevant facts from past weeks/months.
- Preference Management: Store environment-specific configurations (e.g., "always use Yarn over NPM").
- Automatic Context Injection: Automatically fetches relevant "memory documents" before Gemini generates a response.
🛠️ Skills Included
1. store_memory
Saves a specific fact or interaction to the long-term database.
- Input:
fact(string),category(string: 'preference', 'project', 'snippet') - Usage: "Gemini, remember that this project uses MongoDB version 7.0."
2. recall_context
Searches the database for information relevant to the current prompt.
- Input:
query(string) - Logic: Performs a
$vectorSearchagainst thememorycollection.
3. clear_session
Wipes the short-term memory for the current session ID.
📋 Prerequisites
- MongoDB Atlas Cluster (Free Tier works great)
- Gemini API Key
- Node.js / Python environment for the CLI extension
⚙️ Configuration
Add your MongoDB connection string to your environment variables:
The MONGODB_URI value will be read from the mongo.config.json file.
EXPORT MONGODB_URI="mongodb+srv://<user>:<password>@cluster.mongodb.net/gemini_memory"
EXPORT VECTOR_INDEX_NAME="vector_index"
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 45 lines · 14 tokens per session scan A 8cd6bed8caaf
Memory Extension is a skill published in the GitHub repository mongodb-partners/mongodb-gemini-extension (5 stars, last pushed 7mo ago), licensed Apache-2.0. It adds 14 tokens to every session and 404 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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