Claude Fable 5.1 vs OpenAI GPT-6 Astra
Empirical evaluation across autonomous coding benchmarks (SWE-bench Verified, LiveCodeBench), token economics, and multi-agent topology in Swarm.
For autonomous agentic coding where multi-file patch pass rate is paramount, OpenAI GPT-6 Astra holds the verified advantage (-5.8% difference). Both models share identical input pricing at $6/M. In Swarm multi-agent clusters, Both models sit in Tier 1 (Tier 1: Frontier Agentic Lead). Excellent peer redundancy or parallel Coder swarm execution.
Claude Fable 5.1
Primary / PlannerOpenAI GPT-6 Astra
Primary / PlannerStandardized Coding & Reasoning Benchmarks
Verified, contamination-free benchmark scores with direct mathematical deltas.
| Benchmark Metric | Claude Fable 5.1 | OpenAI GPT-6 Astra | Performance Delta |
|---|---|---|---|
| SWE-bench VerifiedReal-world GitHub issues resolved autonomously | 76.2% | 82% | OpenAI GPT-6 Astra (-5.8% difference) |
| LiveCodeBenchPost-training cutoff algorithmic challenges | 67.4% | 84.5% | OpenAI GPT-6 Astra (-17.1% difference) |
| LMSYS Coding EloCrowdsourced blind developer preference | 1435 | 1470 | OpenAI GPT-6 Astra (-35Elo difference) |
| AIME (Competition Math)Deep multi-step deductive reasoning | — | 97% | OpenAI GPT-6 Astra (Only measured on 97) |
Token Economics & Operational Cost Ratio
Pricing per 1M tokens and prompt caching advantages for long-horizon sessions.
Both models share identical input pricing at $6/M.
Output generation costs differ by 1.25x.
Prompt caching significantly reduces long-horizon AST parsing costs during multi-turn Swarm pairing sessions.
Swarm Multi-Agent Topology Synergy
How Swarm orchestrates Claude Fable 5.1 and OpenAI GPT-6 Astra in autonomous engineering clusters.
Claude Fable 5.1
Recommended: Primary / Planner
Orchestrates multi-stage Task Programs with airtight boundary verification.
OpenAI GPT-6 Astra
Recommended: Primary / Planner
High-confidence planning eliminates architectural failures and directs complex Task Programs flawlessly.
When to Choose Which Model
Practical developer recommendations based on real-world engineering workloads.
Choose Claude Fable 5.1 if:
- ✓Intelligence Index 53 with stellar multi-turn task completion
- ✓Resilient against edge-case hallucinations in complex codebases
- ✓Superior instruction obedience in long DAG pipelines
- ✓Need Primary / Planner specialization inside Swarm.
Choose OpenAI GPT-6 Astra if:
- ✓82.0% SWE-bench Verified with native DAG execution awareness
- ✓Ultra-clean unified diff generation with zero whitespace drift
- ✓Instant context switching across multiple concurrent worktrees
- ✓Need Primary / Planner specialization inside Swarm.
Frequently Asked Comparison Questions
Which model is better for autonomous software engineering: Claude Fable 5.1 or OpenAI GPT-6 Astra?
For autonomous agentic coding where multi-file patch pass rate is paramount, OpenAI GPT-6 Astra holds the verified advantage (-5.8% difference). Both models share identical input pricing at $6/M. In Swarm multi-agent clusters, Both models sit in Tier 1 (Tier 1: Frontier Agentic Lead). Excellent peer redundancy or parallel Coder swarm execution. On SWE-bench Verified, Claude Fable 5.1 scores 76.2% vs OpenAI GPT-6 Astra at 82%.
How do Claude Fable 5.1 and OpenAI GPT-6 Astra compare on token pricing and operational economics?
Both models share identical input pricing at $6/M. On cached prompts, Claude Fable 5.1 costs $0.6/M vs OpenAI GPT-6 Astra at $0.8/M.
How does Swarm configure Claude Fable 5.1 and OpenAI GPT-6 Astra in multi-agent workflows?
Both models sit in Tier 1 (Tier 1: Frontier Agentic Lead). Excellent peer redundancy or parallel Coder swarm execution. Swarm isolates code modifications in independent Git worktrees, allowing both models to operate in parallel without colliding working directories or git branch conflicts.