anymodel

name

anymodel

description

AnyModel development skill — the universal AI coding proxy. Use this skill whenever working on AnyModel source code (proxy.mjs, cli.mjs, providers/*, site/*, test/*), adding providers or presets, debugging proxy issues, deploying to npm, or modifying the anymodel.dev website. Also activate when the user mentions AnyModel architecture, proxy sanitization, tool schema fixing, Ollama integration, OpenRouter routing, client branding, or the deployment pipeline. Covers the full AnyModel lifecycle: code, test, publish, deploy.

AnyModel Development Skill

You are working on AnyModel — a universal AI coding proxy that lets you use any AI model through one interface. This skill contains everything you need: architecture, conventions, deployment rules, and debugging guidance.

Product Identity

• Name: AnyModel (capital A, capital M — never "anymodel" or "Any Model" in user-facing text)
• Package: anymodel on npm
• Website: https://anymodel.dev
• GitHub (proxy): https://github.com/anton-abyzov/anymodel
• GitHub (client): https://github.com/antonoly/claude-code-anymodel
• Author: Anton Abyzov (@aabyzov on X, @AntonAbyzov on YouTube)
• License: MIT

Architecture

AnyModel client (cli.js) --> anymodel proxy (:9090) --> OpenRouter / Ollama / OpenAI-compatible

Three components:

1. Proxy (proxy.mjs) — HTTP server intercepting /v1/messages, sanitizes requests, translates formats, routes to providers
2. CLI (cli.mjs) — entry point for starting proxy, connecting, managing presets
3. Bundled client (cli.js) — modified Claude Code client with violet diamond character and AnyModel branding

Providers

Provider	File	API Format	Key Behavior
OpenRouter	providers/openrouter.mjs	Anthropic passthrough	Preserves cache_control, 300+ cloud models
Ollama	providers/ollama.mjs	OpenAI /v1/chat/completions	Injects num_ctx=8192, capability-aware tool passthrough (v1.12.0+)
OpenAI	providers/openai.mjs	OpenAI format	Full bidirectional Anthropic ↔ OpenAI translation
LMStudio	providers/lmstudio.mjs	OpenAI (via local factory)	Delegates to OpenAI translator, :1234/v1 default
llama.cpp	providers/llamacpp.mjs	OpenAI (via local factory)	Delegates to OpenAI translator, :8080/v1 default

Presets (update version in KNOWLEDGE-BASE.md when changing)

Preset	Model ID	Cost
gpt	openai/gpt-5.4	paid
codex	openai/gpt-5.3-codex	paid, coding
gemini	google/gemini-3.1-flash-lite-preview	paid
deepseek	deepseek/deepseek-r1-0528	paid
mistral	mistralai/devstral-2512	paid, coding
gemma	google/gemma-4-31b-it	paid, coding
qwen	qwen/qwen3-coder:free	free
nemotron	nvidia/nemotron-3-super-120b-a12b:free	free
llama	meta-llama/llama-3.3-70b-instruct:free	free

When adding a new preset: add to MODEL_PRESETS in cli.mjs, update help text, update KNOWLEDGE-BASE.md, update site/index.html, update README.md.

Proxy Sanitization (proxy.mjs)

The sanitizeBody() function is the heart of AnyModel. It makes any model work with Claude Code's request format.

What it does (in order):

1. Strips Anthropic-only fields: betas, metadata, speed, output_config, context_management
2. Preserves thinking — reasoning models (DeepSeek R1) need this for chain-of-thought
3. Preserves cache_control for OpenRouter (Anthropic models support it), strips for Ollama/OpenAI
4. Clamps max_tokens to minimum 16 — Claude Code sends max_tokens: 1 for probes, OpenAI/GPT rejects anything below 16
5. Fixes tool schemas:
   • Missing input_schema entirely -> adds minimal valid schema with _unused placeholder
   • Empty properties: {} -> adds _unused placeholder (OpenAI rejects empty properties)
   • Missing type field -> adds "type": "object"
   • Recursively fixes nested schemas (anyOf, oneOf, allOf, items)
   • Strips _unused from tool_use responses so the client never sees it
6. Strips Anthropic-only tool fields: cache_control, defer_loading, eager_input_streaming, strict
7. Normalizes tool_choice: converts string format to object format
8. Local providers (Ollama, LMStudio, llama.cpp): capability-aware tool passthrough — since v1.12.0 the proxy no longer blanket-strips tools. Behavior is controlled by OLLAMA_TOOLS env var (auto default, on, off). In auto mode, the proxy tries tools and caches per-model capability; on "does not support tools" errors it retries without tools and remembers that model as no-tool-support. Tools are then compressed and budget-trimmed via providers/tool-compressor.mjs to fit local context windows (core tools Bash/Read/Write/Edit always kept). Translation: Anthropic tool definitions → OpenAI function format → Ollama message.tool_calls[] → translated back to Anthropic tool_use content blocks with stop_reason: "tool_use". Streaming supported.
9. tool_choice always stripped for Ollama — Ollama doesn't support tool_choice; proxy removes it unconditionally.
10. Auto-retry without tools — if a provider returns "No endpoints found that support tool use" / "does not support tools", proxy retries with tools removed AND caches model as no-tool-support.

Why this matters

Without sanitization, MCP tools break on non-Anthropic models. Claude Code sends 80+ tool definitions including MCP servers (Slack, Figma, Gmail, etc.) with every request. The proxy ensures these schemas are valid for the target model, so MCP works seamlessly through any provider — including local Ollama/LMStudio/llama.cpp models that support function calling (Qwen 3/Coder, Llama 3.1+, Mistral, DeepSeek R1, Gemma 4).

Regression guard: test/ollama-tool-passthrough.test.mjs asserts that in auto mode with an uncached model, tools are forwarded (not stripped). See also test/ollama-tools.test.mjs for the capability-cache logic.

Client Identity

• Character: Violet diamond-themed (diamond-head and diamond-feet ASCII art)
• Color: Light violet rgb(147,130,255), ANSI fallback magentaBright
• Branding: "AnyModel" everywhere (not "Claude Code"). Tips say "Ask AnyModel" not "Ask Claude"
• Version: Synced with npm package via prepublishOnly script
• ANYMODEL_MODEL: Env var displayed in client UI showing active model name

When modifying the client: never break the violet identity. The diamond character and "AnyModel" branding are what distinguish this from standard Claude Code.

Environment Variables

Variable	Purpose
OPENROUTER_API_KEY	OpenRouter API key (primary provider)
OPENAI_API_KEY	API key for OpenAI-compatible endpoints
OPENAI_BASE_URL	Base URL for custom OpenAI-compatible providers
ANYMODEL_CLIENT	Explicit path to client binary
ANYMODEL_MODEL	Model name displayed in client UI
ANYMODEL_TOKEN	Auth token for remote proxy mode
PROXY_PORT	Default port override (default: 9090)
OLLAMA_NUM_CTX	Ollama context size (default: 8192)
LOCAL_NUM_CTX	LMStudio / llama.cpp context size (default: 32768)
OLLAMA_TOOLS	Tool-passthrough mode: auto (default, try + cache), on (always pass), off (always strip — legacy behavior)
OLLAMA_MAX_TOOLS / LOCAL_MAX_TOOLS	Hard cap on tool count for local providers (0 = no cap, rely on budget)
OLLAMA_MAX_TOOL_DESC / LOCAL_MAX_TOOL_DESC	Max chars per tool description (default: 100)
OLLAMA_TOOL_BUDGET_PCT / LOCAL_TOOL_BUDGET_PCT	Fraction of num_ctx reserved for tool schemas (default: 0.30)

Client Discovery (findClient())

When npx anymodel connects, it finds the client in this order:

1. ANYMODEL_CLIENT env var (explicit path)
2. cli.js next to cli.mjs (bundled in npm package)
3. cli.js in current directory
4. Sibling repos (../claude-code/cli.js, ../claude-code-anymodel/cli.js)
5. Home directory (~/claude-code-anymodel/cli.js)
6. Global claude binary (last resort fallback)

Deployment Pipeline (MANDATORY)

Every change MUST follow this pipeline. Never skip steps, never publish without tests passing.

# 1. Run all tests
node --test test/*.test.mjs

# 2. Commit and push
git add <changed-files>
git commit -m "description of change"
git push

# 3. Version bump and publish to npm
npm version patch
npm run sync-version    # syncs version to cli.js
npm publish

# 4. Deploy website (only if site/ changed)
vercel --prod

# 5. Sync client repo (only if cli.js changed)
# Copy cli.js to claude-code-anymodel repo

The prepublishOnly script in package.json handles version syncing. After npm version patch, run npm run sync-version to update the version in the bundled client, then npm publish.

Adding a New Provider

1. Create providers/newprovider.mjs following the pattern in existing providers
2. Export: { name, transformRequest, transformResponse, buildUrl, getHeaders }
3. Add detection logic in cli.mjs (PROVIDERS array)
4. Add env var documentation
5. Handle tool schema translation if the provider's format differs
6. Add tests in test/
7. Update KNOWLEDGE-BASE.md
8. Run the full deployment pipeline

Adding a New Preset

1. Add to MODEL_PRESETS in cli.mjs
2. Update the help text in showUsage()
3. Update KNOWLEDGE-BASE.md preset table
4. Update site/index.html preset section
5. Update README.md
6. Run the full deployment pipeline

Debugging Guide

Common Issues

Symptom	Cause	Fix
max_tokens error	Claude Code sends max_tokens: 1 for probes	Proxy clamps to 16 — check sanitizeBody()
Tool use fails on GPT	Empty properties: {} in tool schema	Proxy adds _unused placeholder — check tool sanitization
Ollama extremely slow	Default 8K context overflowed by big system prompts	Bump OLLAMA_NUM_CTX=32768; tool compressor trims schemas to ~30% of ctx
Local model prints JSON instead of calling tools	Model doesn't support function calling, OR OLLAMA_TOOLS=off, OR model cached as no-tool-support	Use a tool-capable model (Qwen 3 / Qwen-Coder, Llama 3.1+, Mistral, DeepSeek R1, Gemma 4); ensure OLLAMA_TOOLS=auto; restart proxy to clear per-model cache
Slash commands (/openspec, etc.) return JSON text	Same as above — the command emits prompts expecting tool_use blocks; only tool-capable models will emit them	See row above
"No endpoints found" / "does not support tools"	Model doesn't support tool use	Proxy auto-retries without tools and caches model as no-tool-support
Streaming breaks	Response format mismatch	Check provider's transformResponse — Anthropic SSE vs OpenAI SSE
cache_control errors	Non-Anthropic model rejecting cache hints	Check keepCache flag in sanitizeBody()
Client shows "Claude"	Branding not applied	Check ANYMODEL_MODEL env var and client identity patches

Debugging Proxy Traffic

The proxy logs every request with color-coded output:

• [OPENROUTER] / [OLLAMA] / [OPENAI] — provider prefix
• tools=N — number of tools in request
• stream=true — streaming mode
• Yellow [OLLAMA] Passing N tools to <model> (mode=auto) — tools forwarded (capability-aware passthrough, v1.12.0+)
• Yellow [OLLAMA] Stripping N tools (mode=<x>, model=<m> cached as no-tool-support) — tool removal (either OLLAMA_TOOLS=off or model is in no-tool-support cache)
• Yellow [OLLAMA] Tool optimization: N tools (X tok) → compressed to Y tok — schema compression + budget trimming
• Green 200 — successful response
• Red status codes — errors with body excerpt

Competitive Context

Tool	Key Difference from AnyModel
Claude Code Router (CCR)	31K+ stars, Claude Code-specific, requires manual JSON config, no bundled client
OpenRouter native	Only Anthropic models work reliably, no format translation
OpenCode	Full rewrite (107K stars), own ecosystem, not a proxy
Cline	VS Code extension, IDE-specific, not standalone CLI
LiteLLM	Enterprise Python gateway, heavy config

Anthropic Third-Party Cutoff (April 4, 2026)

Claude subscriptions no longer cover third-party tools. AnyModel proxy mode is NOT affected (routes through OpenRouter, never touches Anthropic OAuth). This is a key selling point — AnyModel users don't need a Claude subscription.

URLs and Links

Resource	URL
AnyModel website	https://anymodel.dev
AnyModel npm	https://npmjs.com/package/anymodel
AnyModel GitHub	https://github.com/anton-abyzov/anymodel
Client GitHub	https://github.com/antonoly/claude-code-anymodel
SpecWeave	https://spec-weave.com
Verified Skills	https://verified-skill.com
OpenRouter keys	https://openrouter.ai/keys
YouTube demo	https://youtu.be/k0RI_M6lIsg
YouTube channel	https://youtube.com/@AntonAbyzov
Twitter/X	https://x.com/aabyzov
Discord	https://discord.gg/UYg4BGJ65V
Telegram	https://t.me/antonaipower

File Structure

anymodel/
  cli.mjs              # CLI entry point
  cli.js               # Bundled client (12MB modified Claude Code)
  proxy.mjs            # HTTP proxy server + sanitization
  package.json         # npm config
  providers/
    openrouter.mjs     # OpenRouter provider (passthrough)
    ollama.mjs         # Ollama provider (OpenAI translation + num_ctx + tool_use roundtrip)
    ollama-tools.mjs   # Tool capability mode + per-model no-tool-support cache
    tool-compressor.mjs # Schema compression + budget trimming for local models
    openai.mjs         # OpenAI provider (bidirectional translation)
    openai-local.mjs   # Factory for LMStudio/llama.cpp (thin wrappers over OpenAI)
    lmstudio.mjs       # LMStudio alias (:1234/v1)
    llamacpp.mjs       # llama.cpp alias (:8080/v1)
    prefix-cache.mjs   # Prefix-aware caching (increment 0004)
  site/
    index.html         # anymodel.dev homepage
    styles.css / script.js / sitemap.xml / robots.txt
  test/                # 93+ tests
  KNOWLEDGE-BASE.md    # Single source of truth (keep in sync with this skill)

Testing

Run all tests before any commit:

node --test test/*.test.mjs

Tests cover: sanitization, tool schema fixing, provider translation, preset resolution, max_tokens clamping, streaming, error handling. When adding features, add corresponding tests. The test count should only go up.