NovitàCollega qualsiasi agente a UberLLM: una chiave, tutti i modelli, a prezzo di listino o meno.
UberLLM
Alternativa a OpenRouter

Un’API LLM compatibile con OpenAI per chi lascia OpenRouter

Più economico di OpenRouter su 149 modelli su 150, fino al 99% in meno, al miglior prezzo di UberLLM in questo momento (controllato il 2 novembre 2026).

UberLLM è un’API LLM compatibile con OpenAI e Anthropic per 237 modelli di testo. Le richieste vengono inviate a fornitori terzi su un marketplace e addebitate a token, senza commissioni aggiunte. Per passare da OpenRouter, cambia la base URL e la chiave API.

Prezzi, modello per modello

ModelloUberLLM input / outputOpenRouter input / outputSu UberLLM
GLM-5.2
z-ai/glm-5.2
$0.00056 / $0.0022$0.0060 / $6.8099% in meno
GPT-OSS 120B
openai/gpt-oss-120b
$0.000069 / $0.00030$0.1500 / $0.600099% in meno
GPT-OSS 20B
openai/gpt-oss-20b
$0.000018 / $0.000089$0.0300 / $0.130099% in meno
GPT OSS Safeguard 20B
openai/gpt-oss-safeguard-20b
$0.000074 / $0.00030$0.0750 / $0.300099% in meno
GLM 4.5 Air
z-ai/glm-4.5-air
$0.00013 / $0.00084$0.1300 / $0.850099% in meno
DeepSeek V4 Pro
deepseek/deepseek-v4-pro
$0.0016 / $0.0032$1.60 / $3.2099% in meno
Qwen3.8 2.4T A95B
qwen/qwen3.8-2.4t-a95b
$0.0021 / $0.0063$2.00 / $6.0099% in meno
Qwen: Qwen3.8 Max (0902)
qwen/qwen3.8-max-0902
$0.0022 / $0.0065$2.00 / $6.0099% in meno
Qwen: Qwen3.8 Omni Flash
qwen/qwen3.8-omni-flash
$0.00018 / $0.00056$0.1500 / $0.470099% in meno
MiniMax M2.1
minimax/minimax-m2.1
$0.00036 / $0.0014$0.3000 / $1.2099% in meno
Kimi K2.7 Code
moonshotai/kimi-k2.7-code
$0.00097 / $0.0056$0.6000 / $3.5099% in meno
Kimi K2.6
moonshotai/kimi-k2.6
$0.0013 / $0.0067$0.6500 / $3.4199% in meno
DeepSeek V4.1 Flash
deepseek/deepseek-v4.1-flash
$0.00018 / $0.0014$0.0450 / $0.500099% in meno
GLM 5.3
z-ai/glm-5.3
$0.00070 / $0.0141$0.0800 / $3.6099% in meno
GLM-4.7
z-ai/glm-4.7
$0.0028 / $0.0102$0.6000 / $2.2099% in meno
Gemma 4 26B A4B IT
google/gemma-4-26b-a4b-it
$0.00045 / $0.0015$0.1000 / $0.300099% in meno
GLM 4.7 Flash
z-ai/glm-4.7-flash
$0.00031 / $0.0020$0.0605 / $0.400099% in meno
Kimi K3
moonshotai/kimi-k3
$0.0010 / $0.0788$0.1920 / $15.0099% in meno
GLM-5
z-ai/glm-5
$0.0054 / $0.0174$1.00 / $3.2099% in meno
Gemma 3 27B
google/gemma-3-27b-it
$0.00079 / $0.0020$0.0800 / $0.350099% in meno
Gemma 3 4B IT
google/gemma-3-4b-it
$0.00046 / $0.00058$0.0500 / $0.100099% in meno
Qwen 3 235B A22B Instruct 2507
qwen/qwen3-235b-a22b-2507
$0.00057 / $0.0035$0.0900 / $0.550099% in meno
Gemini 3 Flash Preview
google/gemini-3-flash-preview
$0.0036 / $0.0216$0.5000 / $3.0099% in meno
DeepSeek V4 Flash 0731
deepseek/deepseek-v4-flash-0731
$0.00090 / $0.0018$0.1190 / $0.238099% in meno
Gemma 4 31B IT
google/gemma-4-31b-it
$0.00090 / $0.0034$0.2000 / $0.400099% in meno
Mostra tutti i 150 modelli
ModelloUberLLM input / outputOpenRouter input / outputSu UberLLM
GPT-6 Astra
openai/gpt-6-astra
$0.0799 / $0.3993$10.00 / $50.0099% in meno
Claude Opus 4.7
anthropic/claude-opus-4.7
$0.0400 / $0.2000$5.00 / $25.0099% in meno
Kimi K2.5
moonshotai/kimi-k2.5
$0.0041 / $0.0205$0.5000 / $2.5099% in meno
Grok 4.5
x-ai/grok-4.5
$0.0168 / $0.0505$2.00 / $6.0099% in meno
GLM-4.6
z-ai/glm-4.6
$0.0042 / $0.0170$0.5000 / $2.0099% in meno
Qwen3 Next 80B A3B
qwen/qwen3-next-80b-a3b-instruct
$0.00086 / $0.0095$0.0900 / $1.1099% in meno
MiniMax M2.5
minimax/minimax-m2.5
$0.0024 / $0.0086$0.2700 / $0.950099% in meno
Gemini 3.8 Flash
google/gemini-3.8-flash
$0.0074 / $0.0372$0.8250 / $4.1399% in meno
MiniMax M2
minimax/minimax-m2
$0.0023 / $0.0093$0.2550 / $1.0299% in meno
Claude Sonnet 4.6
anthropic/claude-sonnet-4.6
$0.0285 / $0.1425$3.00 / $15.0099% in meno
Qwen3.8 Flash
qwen/qwen3.8-flash
$0.0014 / $0.0045$0.1500 / $0.470099% in meno
GLM 4.5
z-ai/glm-4.5
$0.0059 / $0.0216$0.6000 / $2.2099% in meno
Gemma 3 12B IT
google/gemma-3-12b-it
$0.00049 / $0.0015$0.0500 / $0.150099% in meno
Qwen3 Coder 30B A3B Instruct
qwen/qwen3-coder-30b-a3b-instruct
$0.00069 / $0.0028$0.0700 / $0.280099% in meno
Qwen3 32B
qwen/qwen3-32b
$0.00079 / $0.0028$0.0800 / $0.280099% in meno
Qwen3 Coder Next
qwen/qwen3-coder-next
$0.0012 / $0.0079$0.1200 / $0.800099% in meno
Qwen 3 Coder 480b
qwen/qwen3-coder
$0.0030 / $0.0099$0.3000 / $1.0099% in meno
Gemini 3.1 Flash Lite
google/gemini-3.1-flash-lite
$0.0025 / $0.0149$0.2500 / $1.5099% in meno
Qwen3 VL 235B A22B
qwen/qwen3-vl-235b-a22b-instruct
$0.0021 / $0.0188$0.2100 / $1.9099% in meno
Gemini 2.5 Flash
google/gemini-2.5-flash
$0.0030 / $0.0248$0.3000 / $2.5099% in meno
Kimi K2 Thinking
moonshotai/kimi-k2-thinking
$0.0059 / $0.0248$0.6000 / $2.5099% in meno
Grok 4.3
x-ai/grok-4.3
$0.0124 / $0.0248$1.25 / $2.5099% in meno
GLM-5 Turbo
z-ai/glm-5-turbo
$0.0119 / $0.0396$1.20 / $4.0099% in meno
Gemini 3.7 Flash
google/gemini-3.7-flash
$0.0075 / $0.0375$0.7500 / $3.7599% in meno
Gemini 3.5 Flash
google/gemini-3.5-flash
$0.0150 / $0.0900$1.50 / $9.0099% in meno
GPT-5.6 Luna
openai/gpt-5.6-luna
$0.0020 / $0.0121$0.2000 / $1.2098% in meno
DeepSeek V3.2
deepseek/deepseek-v3.2
$0.0026 / $0.0039$0.2600 / $0.380098% in meno
NVIDIA Nemotron 3 Ultra 550B
nvidia/nemotron-3-ultra-550b-a55b
$0.0050 / $0.0250$0.6000 / $2.4098% in meno
GLM 5.1
z-ai/glm-5.1
$0.0152 / $0.0479$1.40 / $4.4098% in meno
GLM 5.3 Flash
z-ai/glm-5.3-flash
$0.00033 / $0.0011$0.0285 / $0.092398% in meno
Z.ai: GLM 5.3 Prime
z-ai/glm-5.3-prime
$0.0338 / $0.1063$2.80 / $8.8098% in meno
NVIDIA Nemotron 3 Nano 30B
nvidia/nemotron-3-nano-30b-a3b
$0.00074 / $0.0030$0.0600 / $0.240098% in meno
DeepSeek V4.1 Flash 1017
deepseek/deepseek-v4.1-flash-1017
$0.0045 / $0.0180$0.3000 / $1.2098% in meno
GPT-5.6 Sol
openai/gpt-5.6-sol
$0.0641 / $0.3205$4.00 / $20.0098% in meno
Claude Opus 4.6
anthropic/claude-opus-4.6
$0.0889 / $0.4444$5.00 / $25.0098% in meno
Claude Opus 5
anthropic/claude-opus-5
$0.0900 / $0.4500$5.00 / $25.0098% in meno
GPT-5.6 Terra
openai/gpt-5.6-terra
$0.0378 / $0.2267$2.00 / $12.0098% in meno
OpenAI: GPT-6.1 Terra
openai/gpt-6.1-terra
$0.0196 / $0.0982$1.00 / $5.0098% in meno
Claude Opus 4.5
anthropic/claude-opus-4.5
$0.0985 / $0.4925$5.00 / $25.0098% in meno
GPT-6 Sol
openai/gpt-6-sol
$0.0403 / $0.2013$2.00 / $10.0097% in meno
GPT-4o Mini
openai/gpt-4o-mini
$0.0035 / $0.0138$0.1500 / $0.600097% in meno
GPT-4o
openai/gpt-4o
$0.0589 / $0.2355$2.50 / $10.0097% in meno
GPT-5.4
openai/gpt-5.4
$0.0608 / $0.3648$2.50 / $15.0097% in meno
GPT-5.5
openai/gpt-5.5
$0.1250 / $0.7500$5.00 / $30.0097% in meno
GPT-6 Luna
openai/gpt-6-luna
$0.0030 / $0.0149$0.1000 / $0.500097% in meno
DeepSeek V4 Pro 0813
deepseek/deepseek-v4-pro-0813
$0.0035 / $0.1206$0.1150 / $4.0096% in meno
Qwen 3 235B A22B Thinking 2507
qwen/qwen3-235b-a22b-thinking-2507
$0.0910 / $0.0910$0.4500 / $3.5096% in meno
Qwen 3.5 397B
qwen/qwen3.5-397b-a17b
$0.0179 / $0.1289$0.5000 / $3.6096% in meno
Claude Opus 5.5
anthropic/claude-opus-5.5
$0.1579 / $0.7897$4.00 / $20.0096% in meno
GPT-6.1 Sol
openai/gpt-6.1-sol
$0.0819 / $0.4094$2.00 / $10.0095% in meno
Claude Sonnet 5
anthropic/claude-sonnet-5
$0.0904 / $0.4520$2.00 / $10.0095% in meno
Qwen: Qwen3.7 Flash
qwen/qwen3.7-flash
$0.0014 / $0.0060$0.0300 / $0.130095% in meno
Mistral Large
mistralai/mistral-large
$0.0928 / $0.2784$2.00 / $6.0095% in meno
GPT-5.3 Codex
openai/gpt-5.3-codex
$0.0839 / $0.6711$1.75 / $14.0095% in meno
Claude Fable 5
anthropic/claude-fable-5
$0.4800 / $2.40$10.00 / $50.0095% in meno
Qwen 3.6 27B
qwen/qwen3.6-27b
$0.0159 / $0.1323$0.4500 / $2.7095% in meno
MoonshotAI: Kimi K3.1 Pro
moonshotai/kimi-k3.1-pro
$0.0999 / $0.4995$2.00 / $10.0095% in meno
Claude Opus 4.8
anthropic/claude-opus-4.8
$0.2592 / $1.30$5.00 / $25.0094% in meno
GPT-5.2
openai/gpt-5.2
$0.0927 / $0.7420$1.75 / $14.0094% in meno
Claude Sonnet 5.5
anthropic/claude-sonnet-5.5
$0.1099 / $0.5495$2.00 / $10.0094% in meno
Claude Haiku 4.5
anthropic/claude-haiku-4.5
$0.0581 / $0.2907$1.00 / $5.0094% in meno
MiniMax M3
minimax/minimax-m3
$0.0180 / $0.0719$0.3000 / $1.2094% in meno
Grok 4.7
x-ai/grok-4.7
$0.1200 / $0.3600$2.00 / $6.0094% in meno
MiniMax M2.7
minimax/minimax-m2.7
$0.0192 / $0.0769$0.3000 / $1.2093% in meno
Claude Haiku 5.5
anthropic/claude-haiku-5.5
$0.0071 / $0.0355$0.1000 / $0.500092% in meno
Tencent HY3
tencent/hy3
$0.0095 / $0.0380$0.1320 / $0.528092% in meno
Claude Fable 5.1
anthropic/claude-fable-5.1
$0.7868 / $3.93$10.00 / $50.0092% in meno
Google: Gemini 4 Argon
google/gemini-4-argon
$0.1593 / $0.7963$2.00 / $10.0092% in meno
GPT-5.4 Mini
openai/gpt-5.4-mini
$0.0733 / $0.4401$0.7500 / $4.5090% in meno
GPT 5 Nano
openai/gpt-5-nano
$0.0059 / $0.0471$0.0500 / $0.400088% in meno
GPT-5.4 Pro
openai/gpt-5.4-pro
$4.11 / $24.64$30.00 / $180.0086% in meno
Llama 3.3 70B Instruct
meta-llama/llama-3.3-70b-instruct
$0.0145 / $0.0465$0.1000 / $0.320085% in meno
MiMo-V2.6-Flash
xiaomi/mimo-v2.6-flash
$0.0208 / $0.0416$0.1400 / $0.280085% in meno
Grok 4.6
x-ai/grok-4.6
$0.3564 / $1.07$2.00 / $6.0082% in meno
Claude Sonnet 4.5
anthropic/claude-sonnet-4.5
$0.5505 / $2.75$3.00 / $15.0081% in meno
MiMo-V2.6-Pro
xiaomi/mimo-v2.6-pro
$0.0851 / $0.1701$0.4350 / $0.870080% in meno
GPT 5.4 Nano
openai/gpt-5.4-nano
$0.0396 / $0.2475$0.2000 / $1.2580% in meno
DeepSeek V4 Flash
deepseek/deepseek-v4-flash
$0.0182 / $0.0364$0.0910 / $0.182080% in meno
Gemini 2.5 Pro
google/gemini-2.5-pro
$0.3000 / $2.40$1.25 / $10.0076% in meno
GPT 5 Mini
openai/gpt-5-mini
$0.0612 / $0.4900$0.2500 / $2.0075% in meno
GPT-5.2 Codex
openai/gpt-5.2-codex
$0.4375 / $3.50$1.75 / $14.0075% in meno
GPT-5.6 Luna Pro
openai/gpt-5.6-luna-pro
$0.0599 / $0.3593$0.2000 / $1.2070% in meno
Gemini 3.1 Pro Preview
google/gemini-3.1-pro-preview
$0.6000 / $3.60$2.00 / $12.0070% in meno
GPT-5.5 Pro
openai/gpt-5.5-pro
$9.00 / $54.00$30.00 / $180.0070% in meno
Qwen 3.5 35B A3B
qwen/qwen3.5-35b-a3b
$0.0473 / $0.3151$0.1400 / $1.0068% in meno
Qwen 3.5 9B
qwen/qwen3.5-9b
$0.0300 / $0.0900$0.1700 / $0.250067% in meno
Aion 2.0
aion-labs/aion-2.0
$0.2800 / $0.5600$0.8000 / $1.6065% in meno
Mistral Small 3.2 24B Instruct
mistralai/mistral-small-3.2-24b-instruct
$0.0299 / $0.0798$0.0750 / $0.200060% in meno
Z.ai: GLM 5.3 FlashX
z-ai/glm-5.3-flashx
$0.1480 / $0.5000$0.3700 / $1.2560% in meno
GPT-6 Sol Pro
openai/gpt-6-sol-pro
$0.8000 / $4.00$2.00 / $10.0060% in meno
OpenAI: GPT-6.1 Sol Pro
openai/gpt-6.1-sol-pro
$0.8000 / $4.00$2.00 / $10.0060% in meno
GPT-6 Luna Pro
openai/gpt-6-luna-pro
$0.0400 / $0.2000$0.1000 / $0.500059% in meno
GLM 5V Turbo
z-ai/glm-5v-turbo
$0.4896 / $1.63$1.20 / $4.0059% in meno
Hermes 3 Llama 3.1 405b
nousresearch/hermes-3-llama-3.1-405b
$0.4496 / $0.4496$1.00 / $1.0055% in meno
inclusionAI: Ling 3.1 Flash
inclusionai/ling-3.1-flash
$0.0338 / $0.1013$0.0750 / $0.225055% in meno
MiMo-V2.5-Pro
xiaomi/mimo-v2.5-pro
$0.2160 / $0.8100$0.4800 / $1.8055% in meno
Sakana: Fugu Max
sakana/fugu-max
$0.9200 / $2.76$2.00 / $6.0054% in meno
Sakana: Fugu Ultra v2
sakana/fugu-ultra-v2
$2.30 / $13.80$5.00 / $30.0054% in meno
Qwen 3.7 Plus
qwen/qwen3.7-plus
$0.1648 / $0.6593$0.3200 / $1.2848% in meno
Qwen3 VL 30B A3B
qwen/qwen3-vl-30b-a3b-thinking
$0.1525 / $0.5490$0.2900 / $1.0045% in meno
Mercury 2
inception/mercury-2
$0.1525 / $0.4575$0.2500 / $0.750038% in meno
GPT-5.6 Sol Pro
openai/gpt-5.6-sol-pro
$2.68 / $13.40$4.00 / $20.0032% in meno
Llama 3.2 3B
meta-llama/llama-3.2-3b-instruct
$0.0350 / $0.2310$0.0509 / $0.335031% in meno
Grok Build 0.1
x-ai/grok-build-0.1
$0.6965 / $1.39$1.00 / $2.0030% in meno
Qwen3 30B A3B
qwen/qwen3-30b-a3b
$0.0840 / $0.3500$0.1200 / $0.500030% in meno
Kimi K2
moonshotai/kimi-k2
$0.3990 / $1.61$0.5700 / $2.3029% in meno
GPT-5.6 Terra Pro
openai/gpt-5.6-terra-pro
$1.58 / $9.49$2.00 / $12.0020% in meno
DeepSeek: DeepSeek V4 Flash Vision Exp
deepseek/deepseek-v4-flash-vision-exp
$0.1725 / $0.5174$0.2156 / $0.646820% in meno
Mercury 3
inception/mercury-3
$0.0800 / $0.2800$0.1000 / $0.350019% in meno
Inception: Mercury 2.5
inception/mercury-2.5
$0.0380 / $0.1425$0.0400 / $0.15004% in meno
Mistral: Mistral Large 4
mistralai/mistral-large-4-0
$0.6930 / $2.08$0.7000 / $2.101% in meno
Fireworks: Ember-1
fireworks/ember-1
$2.97 / $14.85$3.00 / $15.001% in meno
Particle AI: Particle-1
particle-ai/particle-1
$0.0495 / $0.4950$0.0500 / $0.50001% in meno
NVIDIA: Nemotron 3.5 Super VL
nvidia/nemotron-3.5-super-vl
$0.1485 / $0.4950$0.1500 / $0.50001% in meno
Reflection: Beam 1.0 501B A23B
reflection/beam-1.0-501b-a23b
$0.2475 / $0.9900$0.2500 / $1.001% in meno
Cohere: Command A+
cohere/command-a-plus
$0.2970 / $1.49$0.3000 / $1.501% in meno
Elorian: Glimpse
elorian/glimpse
$0.5940 / $2.97$0.6000 / $3.001% in meno
Pareto 26.9
unbiased/pareto-26.9
$2.48 / $7.42$2.50 / $7.501% in meno
Qwen: Qwen3.8 Max Prime
qwen/qwen3.8-max-prime
$3.96 / $11.88$4.00 / $12.001% in meno
Moondream: Moondream 3.1
moondream/moondream3.1-9b-a2b
$0.2970 / $2.48$0.3000 / $2.500% in meno
Moondream: Moondream 3 Preview
moondream/moondream3-preview
$0.2970 / $2.48$0.3000 / $2.500% in meno
OpenAI: GPT-6.1 Terra Pro
openai/gpt-6.1-terra-pro
$0.9900 / $4.95$1.00 / $5.000% in meno
MiMo-V2.6-Pro-UltraSpeed
xiaomi/mimo-v2.6-pro-ultraspeed
$4.31 / $8.61$4.35 / $8.700% in meno
LiquidAI: LFM2.5-24B-A2B
liquid/lfm-2.5-24b-a2b
$0.0495 / $0.6930$0.0500 / $0.70000% in meno
Qwen3.7 Max
qwen/qwen3.7-max
$1.89 / $5.63$1.48 / $4.4227% in più

$ per 1M di token in input / output. Nel confronto input e output pesano 1:3. I prezzi UberLLM sono il miglior prezzo sul mercato in questo momento; i prezzi di OpenRouter vengono dal suo elenco pubblico dei modelli. Entrambi controllati il 2 novembre 2026. Elenchiamo ogni modello venduto da tutti e due, anche quelli che qui costano uguale o di più. OpenRouter è un marchio del suo proprietario; i due prodotti sono indipendenti.

Esempio di migrazione

python
from openai import OpenAI

client = OpenAI(
    base_url="https://api.uberllm.dev/v1",   # was: https://openrouter.ai/api/v1
    api_key="ull_your_key_here",
)

resp = client.chat.completions.create(
    model="deepseek/deepseek-v4-flash",
    messages=[{"role": "user", "content": "Hello!"}],
)

UberLLM vs OpenRouter

FunzioneUberLLMOpenRouter
API OpenAI Chat Completions, una chiave per tutti i modelliSìSì
API Anthropic Messages (funziona come backend di Claude Code)Sì, su /v1/messagesSì
API per mediaImmagini, video, musica, sintesi vocale, trascrizioneImmagini, video, sintesi vocale, trascrizione
Come si calcola il prezzo delle richiestePrezzo di mercato in tempo reale, senza commissioni aggiunte: più economico su 149 modelli su 150, fino al 99% in meno, al miglior prezzo di UberLLM in questo momentoIl prezzo di listino del fornitore
Commissione quando ricarichi il credito5,5% + 0,50 $, in aggiunta (25 $ di credito costano 26,88 $)5,5% con il piano Standard, 8% con Business
Usa la tua chiave del fornitoreNessuna commissioneGratis fino a 25.000 $ al mese a prezzo di listino, poi 5%
Limite di spesa per chiave APISì: al giorno, al mese o in totaleSì: un tetto di credito per chiave

I dati su OpenRouter vengono dalla sua pagina pubblica dei prezzi e dalla sua documentazione, controllati il 21 ottobre 2026. I due prodotti sono indipendenti. OpenRouter è un marchio del suo proprietario. Vedi tutti i confronti.

Domande frequenti

UberLLM può sostituire OpenRouter senza modifiche?

UberLLM accetta richieste OpenAI Chat Completions sulla sua base URL, quindi al codice scritto per OpenRouter o OpenAI servono solo un nuovo base_url e una nuova api_key. Le richieste dall’SDK di Anthropic sono accettate su /v1/messages.

In cosa è diverso UberLLM da OpenRouter?

Entrambi offrono una sola chiave API per tanti modelli. UberLLM accetta anche capacità da venditori indipendenti, pubblicata come offerte sul suo marketplace. Ogni richiesta va a un fornitore terzo disponibile per il modello richiesto. Se il fornitore fallisce prima di iniziare a rispondere, la richiesta viene ritentata. Le richieste che falliscono comunque non vengono addebitate. Una richiesta costa quanto ha addebitato il suo fornitore, e ogni richiesta è elencata con il suo costo in Attività. UberLLM non aggiunge commissioni ai prezzi dei fornitori; una commissione carta del 5,5% + 0,50 $ si aggiunge quando ricarichi il credito.

UberLLM ha gli stessi modelli?

Il catalogo include modelli GPT, Claude, Gemini, DeepSeek, GLM, Qwen, Llama, Mistral e Kimi. L’elenco dei modelli mostra quali sono disponibili adesso.

Come passo da OpenRouter a UberLLM?

Imposta base_url su https://api.uberllm.dev/v1 e usa una chiave API di UberLLM. Gli id dei modelli usano la forma fornitore/modello. Controlla che ogni modello che usi sia nel catalogo di UberLLM.