A harnessed image-generation agent: Claude reasons, Cloudflare executes, D1 remembers, OAuth is the only way in.
Limner is an Agent Harness and Model Context Protocol (MCP) server for orchestrating image generation across multiple pipelines, with durable memory for project context. This repository is rasa, the foundation variant of the Limner family. You deploy limner: rasa as your own instance; free-as-in-beer and no strings/data-pipelines attached.
Limner is explicitly built as a compstable harness structure with clean seams:
- The reasoning loop runs on Anthropic's Claude Managed Agents platform. The model does the planning and the tool choice. It never holds provider credentials and never executes code.
- Tool execution runs in Cloudflare V8 isolates. Every tool call lands in a Worker: deterministic TypeScript with explicit bindings, not a shell. Image composition happens in-isolate (WASM codecs, raster ops, text rendering) so the common path costs nothing and leaks nothing.
- The seam between them is an OAuth-gated MCP surface. The agent reaches
the tools the same way any MCP client does: dynamic client registration,
a bearer token, and a typed tool contract at
/mcp. There is no private side channel. - Memory is a database, not a context window. Project briefs, style decisions, and progress notes live in D1 and survive across sessions. The agent recalls what it recorded last week instead of being re-told.
The same tool surface ships three ways from one codebase: the OAuth-gated
Workers endpoint, a local stdio server, and a .mcpb one-click bundle for
Claude Desktop. The stdio server identifies itself as limner-mcp (preview):
stdio is the preview transport at v1, pending a refresh against the next MCP
spec revision. The Workers and .mcpb surfaces carry no preview tag.
The design did not arrive fully formed. The full record lives in docs/Limner_Cloudflare_CMA_Architecture.md: 22 dated decision records, a cost model, and five named off-ramp triggers that state in advance what would make us walk away from the approach.
Several of those records are reversals. The FastAPI shim that fronted the first design was killed. The Sharp/libvips composition path was abandoned for a hybrid WASM stack that runs inside the isolate. Recraft began as a composed first-party MCP and was later amended to a direct REST call, with the transport seam kept as a reusable adapter. One record is a correction: a request timed out at 30s during integration testing and was first blamed on an upstream API, until the API's own docs turned up an async mode and the fault turned out to be ours.
The "Deploy to Cloudflare" button is the cleanest dead-end (currently). We ran the spike on
2026-06-12. The button's monorepo mode extracts a single package into a standalone
repo, which severs the @limner/core workspace dependency and breaks the build.
Provisioning and secrets worked; the repo shape did not. The full note, and the
script that does the same job plus migrations and a smoke test, is under
Where is the Deploy to Cloudflare button?.
- TypeScript pnpm monorepo:
@limner/core(pipelines, composition, state),@limner/mcp(the server, all three transports),@limner/cma-tools(the same tool contract packaged for CMA custom-tool consumption) - Cloudflare Workers, D1, KV, R2, Durable Objects, Images
- Composition: Photon and jSquash (WASM), Satori + resvg for typography, Cloudflare Images for the network-side ops
- MCP over Streamable HTTP and stdio
The architecture document with decision records lives at docs/Limner_Cloudflare_CMA_Architecture.md.
All tools are namespaced limner_*. Full schemas in
packages/limner-mcp/README.md.
| Tool | What it does | Needs |
|---|---|---|
limner_generate_dalle |
OpenAI Images API (gpt-image-1 default) | OPENAI_API_KEY, your OpenAI credit |
limner_generate_recraft |
Recraft, via their REST API (external.api.recraft.ai) |
RECRAFT_API_KEY, your Recraft credit |
limner_generate_midjourney |
Composes a Midjourney prompt string; a human carries it the rest of the way | Nothing |
limner_compose |
16 image ops behind one discriminated union: resize, crop, brightness, contrast, blur, sharpen, watermark, encode, decode, convert, renderText run in-isolate; cfTransform, cfOverlay, cfBlur, cfSmartCrop, cfBackgroundFill use Cloudflare Images | Images binding for the five cf* ops only |
limner_record / limner_recall / limner_forget / limner_list_categories |
Durable memory with categories and idempotent upserts | D1 (or local SQLite) |
limner_list_projects / limner_get_project_context / limner_record_project_note |
Project briefs and running notes | D1 (or local SQLite) |
limner_health / limner_version / limner_list_pipelines / limner_pipeline_capabilities |
Discovery and diagnostics | Nothing |
For a self-deployed Workers stack:
- A Cloudflare account with Workers, D1, and KV available (the free plan covers all three, including SQLite Durable Objects)
- R2 enabled on the account (free tier; the artifact bucket is created for you)
- A Cloudflare Images paid plan for the five
cf*compose ops at real usage volumes - An OpenAI API key and a Recraft API key. Both are required up front; the generation tools spend your own provider credit
- Node per .nvmrc (22; floor 22.13) and pnpm 10
A note on the Images free tier: Cloudflare includes 5,000 unique transformations per month on every account, after which the cf* ops return errors until the month rolls over. That allowance is fine for kicking the tires; treat the paid plan as the requirement for actual use. The eleven in-isolate compose ops never touch Images and stay free everywhere.
Local stdio and .mcpb need no Cloudflare account at all: state goes to
local SQLite, and the cf* compose ops refuse cleanly.
Pick the heaviest option you have patience for. They all end at the same tool surface.
git clone https://github.com/vinsonconsulting/limner.git
cd limner
pnpm install --frozen-lockfile
pnpm setup:cloudflareThe script checks your wrangler login, provisions D1, KV, and R2 by name (re-running is safe), pins the resource ids into the wrangler config, applies the schema migration, builds, deploys, prompts for both provider keys, smoke-tests the deployed endpoint, and prints connect instructions for Claude Desktop, Claude Code, and MCP Inspector.
Optional: pnpm setup:cloudflare --with-example-seed loads a small generic
memory seed (a fictional postcard project) so the memory tools have
something to recall on day one. --env production provisions the separate
production environment, and --dry-run shows the plan without changing
anything.
Sigh... we tried, in a live spike (2026-06-12). The button's monorepo mode
extracts packages/limner-mcp into a standalone repository, which severs
the @limner/core workspace dependency, so the build cannot succeed
regardless of build settings. Its provisioning and secrets flow worked
well; the repo shape is the blocker. The script above does everything the
button would, plus migrations and a smoke test. If the button gains
in-place monorepo support, it returns here.
For push-to-deploy CI/CD in the meantime, connect your fork through the
dashboard: Workers and Pages, import the repository, root directory /,
build command pnpm install --frozen-lockfile && pnpm -r build, deploy
command pnpm --filter @limner/mcp run deploy. That flow keeps the full
repository, so the workspace resolves.
The script above is a convenience wrapper over five wrangler commands; the
by-hand version is in the comments of
packages/limner-mcp/wrangler.toml.
Short form: wrangler d1 create limner-rasa-dev, wrangler kv namespace create OAUTH_KV, wrangler r2 bucket create limner-rasa-artifacts-dev,
pin the printed ids in the config, then wrangler d1 migrations apply limner-rasa-dev --remote, wrangler secret put both keys, and
wrangler deploy.
git clone https://github.com/vinsonconsulting/limner.git
cd limner
pnpm install --frozen-lockfile
pnpm -r build
OPENAI_API_KEY=sk-... RECRAFT_API_KEY=... node packages/limner-mcp/dist/stdio.jsFor Claude Desktop, add to
~/Library/Application Support/Claude/claude_desktop_config.json:
Download the .mcpb from a GitHub release (built on mcpb-v* tags), open
it with Claude Desktop, and fill in the API-key prompts. Or build your own:
pnpm pack:mcpb.
claude mcp add --transport http limner https://limner-mcp.<your-subdomain>.workers.dev/mcpClaude Desktop: Settings, Connectors, add a custom connector with the same
URL. MCP Inspector: npx @modelcontextprotocol/inspector, then connect
with the Streamable HTTP transport. OAuth dynamic client registration
handles credentials in all three cases.
docs/TESTING.md is the tester's checklist, ordered free-first and paid-last, with the cost of every step stated up front. Findings are public issues: use the test finding or bug report template.
Limner is a family of model harnesses. Each variant builds on rasa (this repo) and adds opinions for a specific creative niche.
| Repo | Status | Focus |
|---|---|---|
vinsonconsulting/limner (this repo) |
rasa, foundation | General-purpose; OSS |
vinsonconsulting/limner-pixel |
in development, not yet public | Pixel art, sprite work, retro game asset pipelines |
vinsonconsulting/limner-ascii |
pre-development skill building, not yet public | ASCII art workflows |
Specialty pipelines (pixel-art generators like Pixellab and RetroDiffusion)
are being built in limner-pixel (not yet public); rasa stays
general-purpose. The legacy proprietary work that preceded the OSS pivot is
kept private at vinsonconsulting/limner-pixel-legacy.
Contributions welcome. See CONTRIBUTING.md. All commits
need a Developer Certificate of Origin
sign-off via git commit -s; the DCO check gates merge.
Apache 2.0. See LICENSE.
Limner is built on Anthropic's Claude Managed Agents platform and Cloudflare's CMA hosting. Limner is an independent project; "built on" does not imply endorsement by Anthropic or Cloudflare.
The hero above, translated to pixel art by PixelLab, the pipeline being built as limner-pixel. The family renders its parent.
{ "mcpServers": { "limner": { "command": "node", "args": ["/absolute/path/to/limner/packages/limner-mcp/dist/stdio.js"], "env": { "OPENAI_API_KEY": "sk-...", "RECRAFT_API_KEY": "..." } } } }