Mammoth

mammoth 🦣

Durable memory for your coding agent. Decisions, task history, and code context from past sessions get remembered and recalled automatically — so you stop re-explaining your project every single time. Works locally with zero signup (your memory, your disk, survives reboots), and syncs across machines when you want it to. Any MCP agent — Claude Code, Cursor, Cline, Windsurf, Codex, Gemini — speaks it natively.

caveman make few token. mammoth never forget token.

mammoth is the distribution front-door for two AllSource engines: allsource-prime (semantic recall — graph + vector + temporal over a durable event store) and chronis (cn, event-sourced task/work memory). caveman compresses what you say; mammoth remembers what you said. They compose.

The magic moment

Sessions later, you ask "why did we pick X over Y?" — and the agent answers from memory, without you pasting any history. It recalled a decision from a session it was never in. That's the whole product.

What you get

• A mammoth-memory skill that runs the recall/record loop automatically.
• A voice-identity skill + /voice command — build a durable, queryable voice file (how you think, write, and decide) on the same Prime store, and have any MCP agent write in your voice by recalling the relevant slice. Replaces the viral "100-question interview → static 4k-token markdown blob" pattern with something live, portable, and team-shareable. See docs/proposals/PRIME_VOICE_FILE.md and the proof in tooling/voice-demo/.
• /remember, /recall, /memory-status slash commands (explicit escape hatches).
• The Prime MCP server wired via .mcp.json — 13 prime_* tools (prime_recall, prime_context, prime_add_node, prime_embed, prime_stats, …) plus the prime://auto-context resource: a compressed knowledge index auto-injected into every conversation.

Prerequisite (all agents)

cargo install allsource-prime   # needs >= 0.21.6 (in-process fastembed, no external service)

The binary must be on your PATH.

Install

Claude Code (richest — plugin)

/plugin marketplace add all-source-os/all-source
/plugin install mammoth

Restart and approve the project prime MCP server when prompted. The mammoth-memory skill then activates automatically.

One-line installer (any supported agent)

curl -fsSL https://raw.githubusercontent.com/all-source-os/all-source/main/plugin/mammoth/install.sh | bash

Auto-detects your agents, installs the binary if needed, and writes the MCP config. --print to preview, --help for flags. Windows: install.ps1.

Install matrix

mammoth's core capability is one MCP server — any MCP agent gets all 13 tools by adding one stanza. See INSTALL.md for per-agent placement.

Agent	Path
Claude Code	plugin (above) or project .mcp.json — also gets the skill + slash commands
Cursor	.cursor/mcp.json
Cline	Cline MCP settings
Windsurf	~/.codeium/windsurf/mcp_config.json
Codex	Codex MCP config
Gemini CLI	~/.gemini/settings.json

The shared MCP stanza:

{
  "mcpServers": {
    "prime": {
      "command": "allsource-prime",
      "args": ["--data-dir", "~/.prime/memory", "--auto-inject", "--auto-inject-max-tokens", "1000"]
    }
  }
}

Does it actually work? (benchmarks)

Reproducible harness in tooling/mammoth-bench/ — run it yourself. Recall is scored against a keyword search+grep baseline over the same store, with queries deliberately worded unlike the stored text.

Full run, 60 memories / 60 queries, k=5 (bench2.py):

metric	result	kind
Recall hit@5	0.90 (baseline 0.83, Δ +0.07)	measured
Recall hit@3 / MRR	0.87 / 0.783	measured
Cross-session continuity win-rate	0.07	proxy
Median tokens saved / recall	19 (986 total over 54 hits)	estimate
Recall latency p50 / p95	3.0ms / 3.6ms	measured
Durability (write→restart→read)	PASS	measured

Honest note: on a smaller 18-memory set the edge was +0.17; it narrows to +0.07 as the corpus densifies and the keyword baseline gets more overlap to exploit. Memory still wins every metric. The improvement levers (hybrid keyword+vector, graph depth, a larger embedder) are unused here — headroom, not yet spent. We publish the softening rather than hide it.

How it stores

Local-only by default: allsource-prime --data-dir <project>/.prime runs a fully durable store — WAL (CRC32 + fsync) + Snappy Parquet snapshots, the same AllSource Core engine. Your memory survives restarts and never leaves your machine. No account required.

Cross-machine / team memory is the upgrade: add --sync-to <url> --api-key <key> to ship prime.* events to a hosted AllSource Core.

Free tier remembers across sessions on this machine, no account. Cross-machine and team memory need a free AllSource account.

Provenance

mammoth records its own analysis — decisions, rationale, gotchas, outcomes, metadata, file paths. It does not write raw source code, secrets, or full file contents into memory unless you explicitly allow it.

License

MIT (plugin layer — plugin/mammoth/ + .claude-plugin/). The engines: allsource-prime and allsource-core are Apache-2.0; chronis is MIT. See LICENSE.