Prism Coder

Give your AI agent memory that lasts. Persistent sessions, knowledge graphs, and offline tool-routing — fully local and free.

Prism Coder is an MCP server that gives Claude, Cursor, and other AI tools long-term memory that survives across sessions. It ships with the open-weight prism-coder model fleet (2B–27B) for fast, offline tool-routing — no cloud required.

No account needed. No API keys. Runs on your machine.
A paid subscription adds cloud sync, higher model tiers, and team features through the Synalux portal.

What's New in v20.0.3

Layer 1 Cold-Model Resilience

The reserved-category classifier now retries once with a longer timeout on cold-model failure, then falls back to a deterministic keyword backstop before refusing. Over-length prompts (>4K chars) are classified as UNCERTAIN before reaching the classifier — prompt padding can no longer force the ERROR branch. This eliminates the cold-start refusal problem without weakening the safety gate.

Keyword Backstop for Reserved Content

When the LLM classifier fails (timeout, injection, resource pressure), a deterministic regex floor catches reserved vocabulary (restraint, seclusion, self-harm, suicide, overdose, crisis de-escalation, etc.) including inflected and verb forms. Blocks prompt-padding and classifier-injection attacks on the ERROR path.

Single-Source Safety Text

The safety statement in the MCP server instructions field now imports from boundaries.ts — one source of truth instead of two hand-maintained copies. Boundaries version bumped to v3 with an explicit delivery decision documented in code.

Reserved-Category Safety Gate — All Tiers (v20.0.2)

The Layer 1 semantic classifier now runs for every user, not just paid tiers. Reserved clinical content is refused on free tier when cloud is unavailable — fail-closed.

Ledger Dedup (v20.0.2)

session_save_ledger deduplicates identical entries within a 5-minute window.

Evidence Script (v20.0.2)

scripts/generate-evidence.sh regenerates all 5 evidence files with built-in assertions. Run bash scripts/generate-evidence.sh to verify the full pipeline.

Related MCP server: Knowledge Graph MCP Server

What's New in v20.0.0

License: AGPL-3.0 → Apache-2.0

Prism MCP is now Apache-2.0. The thin-client architecture means all proprietary value (skill resolution, tier gating, billing, cloud inference) lives server-side — the open client carries no moat to protect. Apache-2.0 removes the enterprise adoption friction that AGPL caused.

Thin Client Architecture

Skill routing, budget management, and content resolution have moved server-side to the Synalux portal. The MCP client is now a thin API caller — simpler, smaller, and portable across any host (Claude Code, Gemini, Cursor, autonomous scripts). Offline fallback reads the last successful response from local SQLite.

Clean-Room Voyage AI Adapter

The Voyage AI embedding adapter was independently reimplemented from the Voyage API docs to ensure 100% project-owned copyright. Default model updated to voyage-3.5. See PROVENANCE.md for details.

Server-Side Drift Detection

Session drift detection (GATE 5) no longer requires Claude Code hooks. The timer runs server-side per conversation, piggybacked on every MCP tool response. Works for any host.

CLA Requirement

External contributions now require signing the Individual CLA. The CLA check is merge-blocking on the main branch.

Quickstart

The free tier needs no account, no API key, and no cloud. Add the server to your MCP client:

{
  "mcpServers": {
    "prism": {
      "command": "npx",
      "args": ["-y", "prism-mcp-server"]
    }
  }
}

Open Claude Desktop or Cursor and your agent now has memory backed by a local SQLite database (~/.prism-mcp/data.db).

Optional — local model fleet for offline tool-routing. Pull whichever fits your hardware:

ollama pull dcostenco/prism-coder:2b    # 2.3 GB · mobile / lightweight (99.1% routing accuracy)
ollama pull dcostenco/prism-coder:4b    # 3.4 GB · verifier (100% accuracy)
ollama pull dcostenco/prism-coder:9b    # 5.8 GB · default router (100% accuracy, Qwen3.5)
ollama pull dcostenco/prism-coder:27b   # 16 GB  · complex tasks (100% accuracy)

Prism detects both the namespaced (dcostenco/prism-coder:9b) and bare (prism-coder:9b) Ollama tags automatically.

What it does

Your AI agent forgets everything between sessions. Prism fixes that — and adds verification, drift detection, and multi-agent coordination on top.

Mind Palace — persistent memory that survives across sessions

Every conversation feeds a persistent store. The next session loads the right context automatically — no re-explaining.

The dashboard shows your current project state, pending TODOs, intent health, and a neural knowledge graph — all built automatically from your agent sessions.

Knowledge Graph — semantic + keyword + graph search

Ask "what did I decide about the auth flow last month?" and get an answer with citations, combining vector similarity, full-text search, and graph traversal.

Session History — immutable audit trail

Every session is logged with files changed, decisions made, and TODOs. Search, filter, and replay any past session.

Inference Metrics — see where your tokens go

Every prism_infer call tracks which model handled it (local Ollama vs cloud) and how many tokens were consumed. When you save a session, Prism shows a summary:

📊 Inference Metrics (this session):
  Total calls: 12 — Local: 10 (83%) | Cloud: 2 (17%)
  Prompt tokens: 7,840 evaluated / 8,420 submitted est.
  Completion tokens: 3,150
  Cloud tokens saved (est.): 11,570 — token volume handled locally instead of cloud
  Avg latency: 1,240ms
  By model:
    prism-coder:27b: 6 calls, 7,200 tokens, avg 1,800ms
    prism-coder:9b: 4 calls, 2,870 tokens, avg 620ms
    synalux-27b: 2 calls, 1,500 tokens, avg 1,100ms

Cloud tokens saved is the honest routing metric — it accrues only when local Ollama handles a call that would otherwise have gone to Claude or the Synalux portal. A compact version appears inline after every 5th prism_infer call: 📊 local 10 (83%) · cloud 2 (17%) · ~11,570 tok · avg 1,240ms · 11,570 cloud tok saved.

Local calls use actual Ollama token counts (prompt_eval_count / eval_count from Ollama); cloud calls use char/4 estimates. Metrics are tracked locally — no portal dependency, no env vars, works offline. Per-call data is also forwarded to the Synalux portal as best-effort analytics (independent of the display).

Session Drift Detection

Long agent sessions can wander from their original goal. session_detect_drift compares current work against the stated goal and returns on_track / minor_drift / major_drift so the agent can self-correct.

Behavioral Verification — catch bad edits before they happen

AI agents apply patterns from checklists without understanding the real-world impact. The verify_behavior tool challenges the agent with a scenario it must answer before editing — forcing it to think through what the end user will experience.

Agent: "I'll revert this kitchen display change"
Prism: "⚠️ Scenario: A cook sees a 3-item ticket. One item is voided.
        What should the cook see after the void?"
Agent: "The ticket stays visible with the remaining 2 items."
Prism: "Correct — your revert would hide the ticket entirely."

17 built-in domains (billing, auth, ordering, clinical, HR, and more). Custom domains per workspace on Enterprise. No hooks needed — works in any MCP client.

Time Travel

Roll back to any previous session state. Compare diffs between versions. Restore a known-good state with one click.

Cognitive Routing

Three memory types, automatically sorted: episodic (what happened — session logs, decisions), semantic (what's true — facts, architecture), and procedural (how to do X — workflows, patterns). When you search, the router picks the right store instead of dumping everything.

Multi-Agent Hivemind

Coordinate multiple AI agents working on the same project. Each agent has its own session, but they share memory through the knowledge graph. The Hivemind Radar shows real-time agent status, tasks, and activity.

Neural Search

Search across all memories with highlighted results, knowledge graph editing, and memory density metrics.

Local-first and privacy

The free tier runs entirely on your machine. Paid tiers add cloud sync through the Synalux portal, which is what enables cross-device memory and team sharing.

Handling sensitive data. All cloud writes pass through automatic redaction (SSNs, dates of birth, medical record numbers, phone numbers, emails, and clinical identifiers are stripped before transit). For regulated workloads, run the local tier for full air-gap, or use Enterprise which includes a HIPAA Business Associate Agreement.

Models

The prism-coder fleet uses Qwen3.5 for MCP tool-routing AND general inference. The 9B and 27B are fine-tuned with LoRA (r=128, all 64 layers including DeltaNet); the 2B and 4B use stock Qwen3.5-4B at different quantization levels. The 27B scored 100% on BFCL function-calling and 100% on an internal 15-problem coding eval at $0 inference cost.

prism_infer supports three modes: route (tool routing, fast, nothink), chat (conversation with thinking), and code (code generation with thinking). In chat/code modes, the model uses <think> blocks for chain-of-thought reasoning, which are stripped before the response is served. If the local model fails a quality gate (empty, think-only, or truncated), paid tiers automatically escalate to Claude via the Synalux portal.

Weights: huggingface.co/dcostenco (public GGUF). Latency depends on model size and hardware — see Benchmarks to measure it on your own machine rather than trusting a printed number.

Cascade

query → prism-coder:9b (local router, default)
      → prism-coder:4b (grounding verifier)
      → prism-coder:2b (iPhone / mobile, auto-selected by RAM)
      → prism-coder:27b (complex tasks, on demand)
      → cloud fallback (paid tiers, for max quality)

Multi-Layer Verification

Every tool-grounded answer on paid tiers passes through deterministic L3 routing rules and an NLI grounding verifier before reaching the user. Free-tier users get the deterministic gates (L1, L3-Tool, L3-Tier0) without the model-based NLI check.

Fail-closed on the verified path: when the grounding verifier runs (Standard tier and up), timeout, ambiguity, or missing evidence yields a refusal, not pass-through. Free-tier users get the deterministic L1/L3-Tool gates but not the NLI verifier.

Benchmarks

Reproduce every number yourself. All evals are open-source and self-contained:

git clone https://github.com/dcostenco/prism-coder && cd prism-coder
pip install anthropic requests
python3 tests/benchmarks/prism-routing-100/benchmark.py --models 2b 4b 9b 27b

Routing eval (115 cases, 12 categories, 3-seed mean). Routing accuracy includes the deterministic L3 correction layer — the same rules that run in production. On this narrow tool-routing task all fleet models achieve near-perfect accuracy. Be honest with yourself about what that means: the eval is near-saturated for this taxonomy — it measures whether the right one of a small set of MCP tools is selected, not general capability. The useful takeaway is offline routing reliability at zero cost, not that a 2.3 GB model rivals a frontier model in general.

Memory uplift (LoCoMo-Plus, self-published). A separate long-context dialogue benchmark (dcostenco/Locomo-Plus) measures how much structured memory helps a base model retain multi-day context. Results show large gains when a model is paired with Prism memory versus running raw. Note this benchmark is authored, run, and LLM-judged by this project — treat it as a reproducible demonstration, not an independent third-party result, and run it yourself with the commands in that repo.

Code Generation Quality (27B vs Claude Opus)

Three progressively harder Python tasks run through prism_infer(mode:"code", think:true) on the local 27B and compared with Claude Opus. Both produce correct, production-quality code. The 27B is slightly more verbose (docstrings, examples); Opus is slightly tighter (__slots__, early-exit DFS). On routine coding the 27B at $0 replaces cloud calls entirely.

class TrieNode:
    def __init__(self):
        self.children: dict[str, 'TrieNode'] = {}
        self.is_end_of_word: bool = False

class Trie:
    def __init__(self):
        self.root: TrieNode = TrieNode()

    def insert(self, word: str) -> None:
        node = self.root
        for char in word.lower():
            if char not in node.children:
                node.children[char] = TrieNode()
            node = node.children[char]
        node.is_end_of_word = True

    def search(self, word: str) -> bool:
        node = self._get_node(word.lower())
        return node is not None and node.is_end_of_word

    def starts_with(self, prefix: str) -> bool:
        return self._get_node(prefix.lower()) is not None

    def autocomplete(self, prefix: str, limit: int = 5) -> list[str]:
        node = self._get_node(prefix.lower())
        if node is None:
            return []
        results: list[str] = []
        self._collect_words(node, prefix.lower(), results)
        results.sort()
        return results[:limit]

    def _get_node(self, key: str) -> 'TrieNode | None':
        node = self.root
        for char in key:
            if char not in node.children:
                return None
            node = node.children[char]
        return node

    def _collect_words(self, node: TrieNode, prefix: str, results: list[str]) -> None:
        if node.is_end_of_word:
            results.append(prefix)
        for char, child in sorted(node.children.items()):
            self._collect_words(child, prefix + char, results)

Cloud Escalation in Practice (cloud_fallback: true)

The same three tasks with cloud_fallback: true — the quality gate decides whether local output is good enough or needs cloud escalation.

The quality gate detected repeated sentences (≥3 of the same sentence in ≥6 total) in the 27B's Trie output and escalated automatically. The cloud fallback returned clean code. On a second run of the same prompt, the 27B produced clean output without escalation — the loop is stochastic, not systematic.

Takeaway: for ~80–90% of coding tasks, the 27B handles everything locally at $0. The quality gate + cloud escalation exists as a safety net for the remaining cases where the local model loops, truncates, or produces empty output. Paid tiers get automatic escalation; free tier gets the local result with a warning.

Why Prism Coder

vs AI coding assistants

These tables are the maintainer's assessment as of June 2026. Verify claims that matter to you — products change fast.

vs local AI / memory tools

Pricing — flat-rate, not per-seat

Plans

All on-device models are free to run locally via Ollama on every tier. A subscription gates cloud features, higher model ceilings, and increased limits. Local model ceilings are advisory — on-device models run on your Ollama regardless of plan; the ceiling gates cloud inference and prism_infer routing.

14-day free trial on paid plans. 25+ seats: contact sales

How agents use it

Prism exposes 40+ MCP tools. The core memory loop:

prism_infer — local-first inference with cloud escalation

prism_infer({
    prompt: "Write a binary search in Python",
    mode: "code",        // "route" | "chat" | "code"
    think: true,          // enable <think> reasoning (default: true for chat/code)
    model_ceiling: "27b", // use the quality tier
})
// → 27B generates code locally ($0), with thinking for quality
// → If quality gate fails + paid tier → auto-escalate to Claude

Full TypeScript signatures live in src/tools/; architecture in docs/ARCHITECTURE.md.

inference_metrics — see your local-model usage on demand

Call inference_metrics anytime mid-session to see how many prism_infer calls ran locally vs cloud, with actual token counts:

📊 Inference Metrics — local-model delegation (this session):
  Total calls: 5 — Local: 5 (100%) | Cloud: 0 (0%)
  Tokens: 1,240 in + 380 out = 1,620 total
  Avg latency: 420ms
  By model:
    prism-coder:27b: 3 calls, 1,100 tokens, avg 520ms
    prism-coder:9b: 2 calls, 520 tokens, avg 270ms

The same block also appears automatically in session_save_ledger and session_save_handoff responses at session end.

Note: This tracks prism_infer delegation only — not your host model's (Claude's) own token spend. For that, use Claude Code's /cost command.

Local-model delegation (opt-in)

By default, your AI agent (Claude, Cursor, etc.) handles everything itself. You can optionally enable delegation so the agent offloads cheap, verifiable sub-tasks to local Ollama models at $0:

# Enable via Prism config
prism config set delegation_enabled true

When enabled, the agent's task router may delegate qualifying work — bulk classification, field extraction, mechanical formatting — to prism_infer instead of using cloud tokens. The agent always verifies the result and redoes it itself if quality is degraded.

Guardrails:

• Off by default — enforced in code, not just convention

• Never delegates: code/text that ships to the user, security/safety logic, planning/reasoning, anything where a silent quality drop isn't obvious

• Always verifies: checks quality_gate_failed and used_cloud before trusting local output

The LLM context window is treated as ephemeral scratch space; durable state lives in the persistent store (SQLite locally, the portal in the cloud). Every session begins with a mandatory session_load_context call, so the agent is oriented before it writes a response. When a project exceeds a threshold (default 50 entries), session_compact_ledger summarizes old entries into a rollup, soft-archives the originals, and links them in the graph. See docs/COMPACTION.md

CLI

prism load <project>      # load session context
prism save                # save ledger + handoff
prism search <query>      # search code across repos (exact / regex / symbol / semantic)
prism review <files...>   # AI code review — security, performance, style
prism scan <files...>     # security scan — secrets, licenses, Dockerfile
prism push                # push local SQLite to the cloud backend
prism register-models     # alias dcostenco/prism-coder:* -> prism-coder:*

prism search — semantic code search

prism review — AI code review with HIPAA checks

prism scan — security scanner for secrets, Dockerfiles, licenses

Companions

Prism works alongside these tools — use whichever fits your workflow.

Web IDE — Prism Coder

A browser-based IDE at synalux.ai/coder. Import any GitHub repo and get:

• Monaco editor with multi-tab, split view, syntax highlighting, and VS Code keybindings

• In-browser Node.js via WebContainer (your code runs in the browser sandbox, not on a server)

• Integrated terminal — WebContainer shell in-browser; optional server PTY via WebSocket when connected to a dev server

• AI Agent Mode — describe a task and the agent creates files, runs type-checks, and verifies

• Source control — commit, branch, push/pull, stash, blame, tag management

• Live Share — real-time collaborative editing with session links

• Node.js debugger via Chrome DevTools Protocol

• Tasks runner (VS Code tasks.json compatible), Problems panel (Monaco diagnostics)

• 12-language i18n — full UI localization

Standard+ plans get cloud AI and higher rate limits. Free tier works with local Ollama. Code execution uses the in-browser WebContainer by default; Live Share and the optional PTY terminal connect to external servers when explicitly enabled.

VS Code Extension — Synalux

Memory-augmented AI inside VS Code with clinical practice management features. Install from the marketplace:

code --install-extension synalux-ai.synalux

AI chat, voice input, SOAP note generator, team collaboration, and video calls — all inside VS Code. Routes through local Ollama by default; cloud on paid tiers.

• AI: Chat participant (@synalux), multi-agent pipeline, voice input, model switching, 10 tones

• Clinical: SOAP note generator, role-based access, document signing, patient board

• Collaboration: Team chat, DMs, video calls, customer board, visual builder, DevContainers

• Privacy: Local Ollama by default. preferLocal=true tries local first. Enterprise BAA available.

Prism AAC

Communication app for non-speaking users, powered by the on-device prism-coder fleet for phrase prediction. macOS / iOS / web.

See github.com/dcostenco/prism-aac

Git Hooks (Portable)

Pre-commit and pre-push security hooks that work with any editor, any AI tool, and direct CLI. No Claude Code dependency.

# Install in all repos (one-time)
bash hooks/install.sh

# Or install manually in a single repo
cp hooks/pre-commit .git/hooks/pre-commit && chmod +x .git/hooks/pre-commit
cp hooks/pre-push .git/hooks/pre-push && chmod +x .git/hooks/pre-push

Default mode is advisory (warn but allow). Set *_MODE=block for hard enforcement. Hooks look for full audit scripts in the repo first (hooks/lib/), then ~/.claude/hooks/ fallback, then minimal inline checks.

Self-hosting (Enterprise)

Run the full model stack on your own hardware — no cloud, full data sovereignty.

Requirements: Mac M2 Pro+ (48 GB recommended) or Linux + NVIDIA GPU, plus Ollama.

ollama pull dcostenco/prism-coder:9b       # default router
export LOCAL_LLM_URL=http://localhost:11434

Routing is automatic: 9b → 4b → cloud fallback on desktop/server, 2b → cloud fallback on mobile/iPhone. For iOS or another machine on the same network, run OLLAMA_HOST=0.0.0.0 ollama serve and point LOCAL_LLM_URL at the host's IP.

Configuration reference

With no variables set, Prism runs fully local. Set PRISM_SYNALUX_API_KEY (and leave PRISM_STORAGE=auto) to use the cloud backend.

Testing

npm test                 # full suite (vitest) — 95 files, 2841 tests
npm test -- --coverage   # coverage report

Coverage spans HRR retrieval, knowledge ingestion, the inference cascade and grounding verifier, inference metrics, telemetry allowlist, delegation gate, compaction, the model picker, and storage round-trips.

Migration: local to cloud

To move free-tier history into the paid portal:

node scripts/migrate-local-to-portal.mjs --dry-run        # preview, no network
PRISM_SYNALUX_API_KEY=synalux_sk_... \
  node scripts/migrate-local-to-portal.mjs                # push ledger + handoffs

It reads ~/.prism-mcp/data.db and POSTs entries to the portal. Ledger entries are append-only and de-duped server-side; handoffs use last-write-wins per project. Re-running on the same DB is safe. This is a one-shot migration, not a sync daemon — after it, set PRISM_STORAGE=synalux (or leave it on auto).

License & Tiers

This repository (the Prism MCP client) is licensed under Apache-2.0.

Free (no account)

Paid (Synalux subscription)

Everything in Free, plus:

The paid tier adds intelligent routing — the Synalux portal determines which skills are relevant to your current project and prompt, so your agent gets domain expertise (stripe patterns, training protocols, clinical standards) instead of loading everything. Free users with the repo can run sync-skills.sh to populate all skills locally; paid routing adds project-aware and prompt-aware selection.

• Contributions require signing the CLA.

• "Prism" and "Synalux" are trade names of Synalux LLC; the Apache license does not grant trademark rights (see §6 of the license).

License change (v20)

As of this release, prism-mcp is relicensed from AGPL-3.0 to Apache-2.0. Prior versions remain under AGPL-3.0. Existing forks retain all rights received under the original license.

This repository is licensed under Apache-2.0. Cloud features (hosted inference, cross-device memory, team features) are provided by the Synalux cloud service under separate terms.

© 2026 Synalux, LLC.