AI agents · OpenClaw · self-hosting · automation

Quick Answer

Muse Spark 1.1 vs Grok 4.5: Cheap Coding Agent (July 2026)

Published:

Rate Card vs Reality (July 13, 2026)

Meta’s Muse Spark 1.1 opened its paid API on July 9, 2026, undercutting every other frontier model on published input token cost. Grok 4.5 shipped a day earlier (July 8) at slightly higher rates but with better token efficiency. Here’s the actual comparison for a coding agent workload.

Model$/MTok in$/MTok outTPSTerminal-Bench 2.1Real cost per task*
Muse Spark 1.1$1.25$4.25~5580.0 (Meta) / ~70 (indep.)~$0.26
Grok 4.5$2.00$6.00~8083.3~$0.35
GPT-5.6 Luna$1.00$6.00~45~74~$0.40
Claude Haiku 4.5$1.00$5.00~65~72~$0.45

*From Artificial Analysis’ coding evaluation suite, July 2026. “Real cost” bakes in the actual output tokens generated to complete a task — Muse Spark 1.1 needs ~94M output tokens vs Luna’s 125M and GLM-5.2’s 141M for the same benchmark suite.

The Meta Claim vs Independent Benchmark Gap

Meta’s own numbers for Muse Spark 1.1:

  • Terminal-Bench 2.1: 80.0
  • SWE-Bench Pro: 61.5
  • DeepSWE 1.1: 53.3

Artificial Analysis and TechTimes ran independent evaluations and found Muse Spark 1.1 scoring roughly 10 points below Meta’s Terminal-Bench figure. The Artificial Analysis Intelligence Index puts it at 51 — an 8-point gain from the original Muse Spark, but still behind GPT-5.6 Terra (~58) and Claude Sonnet 5 (~62).

Takeaway: Muse Spark 1.1 is Meta’s first paid API, and Meta appears to be running favorable benchmark configurations. Trust the independent numbers.

Grok 4.5’s Structural Advantage

Grok 4.5 costs more per input/output token but generates fewer output tokens per task. On the Harvey Legal Agent Benchmark, Grok 4.5 sits at #1. On Terminal-Bench 2.1 it beats Muse Spark 1.1 by 3.3 points on Meta’s own scoring (and ~13 points on independent scoring).

More importantly for agentic workflows: Grok 4.5 outputs about 4.2× fewer tokens per finished task than Opus 4.8, and roughly 1.5× fewer than Muse Spark 1.1 on comparable tasks. In agent loops where the model calls itself dozens of times, that compounds fast.

Grok 4.5 also has Grok Build — native Office output (Excel models, PowerPoint decks, Word docs). Muse Spark 1.1 doesn’t have that yet.

When to Use Which

Use Muse Spark 1.1 if:

  • You’re high-volume, cost-sensitive, US-based
  • Your workload is single-shot code generation, not long agent loops
  • You can tolerate the 10-point gap between Meta’s claimed and independent benchmark scores
  • You want the absolute cheapest per-token frontier model on the market

Use Grok 4.5 if:

  • Your agent runs 30+ steps
  • You need Office document output
  • Token efficiency matters more than token rate
  • You’re doing legal, terminal, or long-horizon work

Use neither if:

  • You’re in the EU (Muse Spark 1.1 is US-only, Grok 4.5 has partial coverage)
  • Task requires frontier reasoning → route to Opus 4.8 or Sol Ultra
  • Task requires open weights → route to DeepSeek V4 Pro

The Bigger Picture

Meta’s move into paid API pricing is a strategic pivot. Zuckerberg spent years positioning Meta as the open-weight AI alternative. Muse Spark 1.1 marks the moment Meta joined OpenAI and Anthropic in the paid-API business — undercutting them on rate card while keeping some Llama-line weights open.

Combined with OpenAI temporarily relaxing GPT-5.6 Sol usage limits on July 12 and Grok 4.5’s July 8 launch, the AI cheap-tier price war is in full escalation. Expect Anthropic to respond within the next 30 days — either a Haiku 4.6 price cut or a new sub-Haiku tier.

Sources