Compare Claude Fable 5 and GPT-5.6 Sol: Frontier Intelligence and Long-Horizon Agents
Claude Fable 5 vs GPT-5.6 Sol: which should I use?
Claude Fable 5 and GPT-5.6 Sol represent the apex of AI intelligence. Fable 5 offers unmatched deep reasoning for mission-critical tasks ($10.00/M input, $50.00/M output), while Sol provides general agentic coding and 128K max output headroom. Verified 2026-09-07.
Verified 2026-09-07
Where can you find price, speed, and task evidence for Claude Fable 5 and GPT-5.6 Sol?
Which tasks fit Claude Fable 5 and GPT-5.6 Sol?
Best-fit task signals from the published model strengths; this is not a substitute for a controlled benchmark.
| Fact | Claude Fable 5 | GPT-5.6 Sol |
|---|---|---|
| Best fit | The most demanding reasoning and long-horizon agentic work. | Complex, multi-step professional and coding work where accuracy matters more than cost. |
| Reasoning mode | Available | Available |
What does a Coding Agent workload cost with Claude Fable 5 and GPT-5.6 Sol?
Modeled for Coding Agent: 20,000 input + 2,000 output tokens per task, 1 turn. This is a workload model, not a provider quote.
| Fact | Claude Fable 5 | GPT-5.6 Sol |
|---|---|---|
| Coding Agent / task | $0.30 (modeled) | $0.12 (modeled) (winner) |
| Input / output rate | $10.00 / $50.00 per M | $4.00 / $20.00 per M |
How fast are Claude Fable 5 and GPT-5.6 Sol?
Only non-estimated benchmark results are shown as measured.
| Fact | Claude Fable 5 | GPT-5.6 Sol |
|---|---|---|
| Measured throughput | 41 tokens/s | 44 tokens/s (winner) |
| Time to first token | 610 ms | 560 ms |
How compatible are Claude Fable 5 and GPT-5.6 Sol with APIs?
Provider-level wire-format and SDK facts; model-specific parameter differences may still apply.
| Fact | Claude Fable 5 | GPT-5.6 Sol |
|---|---|---|
| OpenAI SDK | Not drop-in | Usable |
| Request shape | Messages API — system prompt is a top-level field, not a message role, and max_tokens is required on every call. | Canonical /chat/completions and /responses shape — every OpenAI-compatible provider on this site imitates it. |
| Streaming | SSE (Anthropic content-block events) | SSE (OpenAI delta) |
What are the privacy and retention policies for Claude Fable 5 and GPT-5.6 Sol?
Provider policy and residency facts from the verified provider registry. A missing retention policy is not treated as a guarantee.
| Fact | Claude Fable 5 | GPT-5.6 Sol |
|---|---|---|
| Provider says API data trains models | No | No |
| Published retention period | Unavailable | Unavailable |
| Data residency | Unavailable | US by default; EU data residency available on enterprise agreements |
How much effort does it take to migrate between Claude Fable 5 and GPT-5.6 Sol?
Direction is from each displayed model to the other. Effort is derived from provider compatibility and published parameter maps.
| Fact | Claude Fable 5 | GPT-5.6 Sol |
|---|---|---|
| Move Claude Fable 5 → GPT-5.6 Sol | config; 3 breaking parameter differences | Target: GPT-5.6 Sol |
| Move GPT-5.6 Sol → Claude Fable 5 | Source: GPT-5.6 Sol | code-change; 8 breaking parameter differences |
| Why | Keep the `openai` SDK; change `baseURL` and the API key. | Messages API — system prompt is a top-level field, not a message role, and max_tokens is required on every call. |
Batch 53 · exact pair cross-provider decision contributions. Surface verification: 2026-09-02. These three boards are server-rendered from frozen scenarios; assumptions and unavailable joins are not observations.
Exact pair boundary: requested models are claude-fable-5 and gpt-5.6-sol. Provider, pricing, task, and rate-limit pages remain fact owners.
Fable/Sol effort-and-tool comparability compiler
Frozen Batch 53 scenario board. Formula / decision rule: comparable = exact host/ID ∧ prompt/config hash match ∧ tool policy match ∧ documented effort mapping; otherwise No mapping Boundary: Similarly named effort controls are not equal without first-party evidence; this module does not create a model winner.
| Frozen scenario / field ID | Joined fields and evidence | Output | State |
|---|---|---|---|
batch53-claude-fable-5-vs-gpt-5-6-sol-m1-r1frozen default effort | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; pair=claude-fable-5 vs gpt-5.6-sol; requested=claude-fable-5,gpt-5.6-sol; effective=claude-fable-5,gpt-5.6-sol; surface=Anthropic Messages/OpenAI Responses; control=default; tool policy=none; prompt/config hash=fable-sol-effort-default; evidence=2026-09-02 | Unavailable — default effort equivalence is not documented across the two providers | NO MAPPING — default labels differ |
batch53-claude-fable-5-vs-gpt-5-6-sol-m1-r2matched medium | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; surface=Anthropic Messages + OpenAI Responses; control=medium on both; tools=none; prompt/config hash=fable-sol-effort-medium; source/date=first-party | Unavailable — cross-provider medium semantics and reasoning accounting are not joined | CONDITIONAL — paired probe required |
batch53-claude-fable-5-vs-gpt-5-6-sol-m1-r3matched high | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; surface=Anthropic Messages + OpenAI Responses; control=high on both; tools=declared; prompt/config hash=fable-sol-effort-high; result hash=missing | Unavailable — matched result and acceptance rubric are missing | UNAVAILABLE — no reproducible pair run |
batch53-claude-fable-5-vs-gpt-5-6-sol-m1-r4Fable max versus Sol xhigh | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; Fable control=max; Sol control=xhigh; host and exact IDs pinned; prompt/config hash=fable-max-sol-xhigh | Do not score this as a matched setting; max and xhigh have no evidenced equivalence. | NOT COMPARABLE — control mismatch |
batch53-claude-fable-5-vs-gpt-5-6-sol-m1-r5Sol ultra | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; Fable control=No mapping; Sol control=ultra; requested/effective IDs pinned; source/date=first-party | Sol ultra is retained as a requested control, not transferred to Fable. | UNSUPPORTED — no Fable counterpart |
batch53-claude-fable-5-vs-gpt-5-6-sol-m1-r6mismatched-tool fixtures | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; Fable tools=search+write; Sol tools=none; prompt/config hash=fable-sol-tools-mismatch; side_effects=uncontained | Exclude from capability delta because tool access is a confounder. | NOT COMPARABLE — tool policy mismatch |
Provenance: Batch 53 claude-fable-5-vs-gpt-5-6-sol; first-party source OpenAI model documentation; surface verification date 2026-09-02. Missing joins fail closed.
Flagship long-horizon evidence receipt
Frozen Batch 53 scenario board. Formula / decision rule: pass = exact IDs ∧ prompt/tool/result hashes ∧ shared rubric ∧ side-effect settlement; otherwise Unavailable Boundary: Only matched, reproducible pair runs can support this route; task-page winners and provider claims remain outside the receipt.
| Frozen scenario / field ID | Joined fields and evidence | Output | State |
|---|---|---|---|
batch53-claude-fable-5-vs-gpt-5-6-sol-m2-r1repository repair | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; pair=claude-fable-5 vs gpt-5.6-sol; requested=claude-fable-5,gpt-5.6-sol; effective=claude-fable-5,gpt-5.6-sol; run IDs=fable-sol-repair-a,b; prompt/tool/result hashes=required; acceptance=tests+review; side_effects=isolated; evidence=2026-09-02 | Unavailable — raw run exports and paired test outcomes are absent | UNAVAILABLE — reproducibility gap |
batch53-claude-fable-5-vs-gpt-5-6-sol-m2-r2multi-source research | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; surface=both API hosts; run IDs=required; prompt hash=research-001; tool trace=citations; result hash=missing; freshness=dated | Unavailable — source IDs, query timestamp, and paired support coverage are not joined | UNAVAILABLE — provenance gap |
batch53-claude-fable-5-vs-gpt-5-6-sol-m2-r3architecture plan | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; exact IDs pinned; prompt/config hash=arch-002; acceptance rubric=declared; steps completed and reviewer=missing | Unavailable — completed-step evidence and reviewer denominator are absent | UNAVAILABLE — acceptance gap |
batch53-claude-fable-5-vs-gpt-5-6-sol-m2-r4agent recovery | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; tool-call/result IDs=required; checkpoint hash=recovery-003; attempt cap=2; side-effect ledger=required | Recovery may be admitted only after checkpoint, replay, and side-effect hashes settle. | CONDITIONAL — recovery evidence required |
batch53-claude-fable-5-vs-gpt-5-6-sol-m2-r5adversarial review | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; prompt hash=adversarial-004; tool policy=none; rubric=recall+false-positive ceiling; model/version/judge=required | Unavailable — shared judge, denominator, and raw outputs are missing | UNAVAILABLE — asymmetric evidence |
batch53-claude-fable-5-vs-gpt-5-6-sol-m2-r6missing-raw-output fixtures | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; run IDs and aggregate score present; raw output hash=missing; host/effort/tool fields=partial | Aggregate figures cannot be replayed or compared without raw outputs. | FAIL CLOSED — raw output required |
Provenance: Batch 53 claude-fable-5-vs-gpt-5-6-sol; first-party source Anthropic Claude model documentation; surface verification date 2026-09-02. Missing joins fail closed.
Planner-builder-reviewer routing board
Frozen Batch 53 scenario board. Formula / decision rule: release = all stage gates pass ∧ handoff hash matches ∧ attempt cap respected; irreversible side effects require human approval Boundary: This is exact-pair orchestration, not a generic agent architecture recommendation.
| Frozen scenario / field ID | Joined fields and evidence | Output | State |
|---|---|---|---|
batch53-claude-fable-5-vs-gpt-5-6-sol-m3-r1Fable-only | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; stage=planner+builder+reviewer; exact ID=claude-fable-5; handoff artifact hash=required; attempt_cap=2 | Route remains Fable-only only under the declared acceptance rubric Measurement state: labeled assumption only. | ASSUMPTION — observe workload first |
batch53-claude-fable-5-vs-gpt-5-6-sol-m3-r2Sol-only | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; stage=planner+builder+reviewer; exact ID=gpt-5.6-sol; handoff artifact hash=required; attempt_cap=2 | Route remains Sol-only only under the declared acceptance rubric Measurement state: labeled assumption only. | ASSUMPTION — observe workload first |
batch53-claude-fable-5-vs-gpt-5-6-sol-m3-r3Fable-plan/Sol-build | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; planner=Fable; builder=Sol; handoff hash=required; tools=repository; side_effects=isolated; rate links=dated | Unavailable — cross-provider handoff and paired acceptance are not observed | UNAVAILABLE — handoff evidence missing |
batch53-claude-fable-5-vs-gpt-5-6-sol-m3-r4Sol-build/Fable-review | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; builder=Sol; reviewer=Fable; artifact hash=required; reviewer rubric=declared; result hash=missing | Unavailable — reviewer acceptance and incremental rate join are absent | UNAVAILABLE — reviewer join missing |
batch53-claude-fable-5-vs-gpt-5-6-sol-m3-r5dual-review disagreement | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; reviewers=Fable+Sol; disagreement hash=required; human adjudicator=required; attempt_cap=2 | Escalate to a human when reviewers disagree; no automatic release. | BLOCKED — human adjudication required |
batch53-claude-fable-5-vs-gpt-5-6-sol-m3-r6irreversible-tool scenarios | pair=claude-fable-5 vs gpt-5.6-sol; surfaces=Anthropic Messages@api.anthropic.com / OpenAI Responses@api.openai.com; requested IDs=claude-fable-5,gpt-5.6-sol; effective IDs=claude-fable-5,gpt-5.6-sol; tool=write/delete; idempotency key=required; rollback artifact=required; human approval=required | Contain the action and require human approval before any uncontained side effect. | BLOCKED — approval gate |
Provenance: Batch 53 claude-fable-5-vs-gpt-5-6-sol; first-party source OpenAI Responses API; surface verification date 2026-09-02. Missing joins fail closed.
Method and limitations: every formula is deterministic and every assumption is labeled. Missing provider, host, alias, snapshot, version, effort, tool, modality, benchmark, workload, rate-period, timestamp, or result joins fail closed. Run the claude-fable-5-vs-gpt-5-6-sol Batch 53 scenario →
Batch 64 · exact-pair decision contributions · verified 2026-09-07
Exact pair boundary: Anthropic / OpenAI; model endpoint, absolute frontier reasoning, extended thinking vs native reasoning, and premier token tariffs must join. Requested models are claude-fable-5 and gpt-5.6-sol. Provider, rate, pricing, and task pages remain fact owners.
Premier token pricing and promotional transition ledger
Frozen Batch 64 scenario board. Formula / deterministic rule: spend_delta = fable_monthly_cost - sol_monthly_cost; Sol promo ends 2026-11-21 Boundary: Owns pricing differential modeling between premier frontier flagships.
| Frozen scenario / field ID | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch64-claude-fable-5-vs-gpt-5-6-sol-m1-r11K mission-critical proofs | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=1K mission-critical proofs; workload volume; Fable 5 spend; Sol promo spend; Sol standard spend; cost difference; economic verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 1K mission-critical proofs is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-claude-fable-5-vs-gpt-5-6-sol-m1-r210K high-stakes agentic coding tasks | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=10K high-stakes agentic coding tasks; workload volume; Fable 5 spend; Sol promo spend; Sol standard spend; cost difference; economic verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 10K high-stakes agentic coding tasks is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-claude-fable-5-vs-gpt-5-6-sol-m1-r350K complex repository refactors | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=50K complex repository refactors; workload volume; Fable 5 spend; Sol promo spend; Sol standard spend; cost difference; economic verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 50K complex repository refactors is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-claude-fable-5-vs-gpt-5-6-sol-m1-r4prompt caching active (Fable 90% read / Sol 50%) | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=prompt caching active (Fable 90% read / Sol 50%); workload volume; Fable 5 spend; Sol promo spend; Sol standard spend; cost difference; economic verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — prompt caching active (Fable 90% read / Sol 50%) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-claude-fable-5-vs-gpt-5-6-sol-m1-r5batch queue active (50% both) | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=batch queue active (50% both); workload volume; Fable 5 spend; Sol promo spend; Sol standard spend; cost difference; economic verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — batch queue active (50% both) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-claude-fable-5-vs-gpt-5-6-sol-m1-r6unresolved pricing currency | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=unresolved pricing currency; workload volume; Fable 5 spend; Sol promo spend; Sol standard spend; cost difference; economic verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unresolved pricing currency has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: OpenAI API pricing; verification date 2026-09-07. Missing or conflicting joins fail closed.
Mission-critical error prevention and economic return on investment
Frozen Batch 64 scenario board. Formula / deterministic rule: roi = prevented_loss_value - ((step_in * rate_in + step_out * rate_out) / 1M) Boundary: Owns return-on-investment modeling for high-stakes enterprise decisions.
| Frozen scenario / field ID | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch64-claude-fable-5-vs-gpt-5-6-sol-m2-r1smart contract security vulnerability audit | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=smart contract security vulnerability audit; domain task; error impact value; Fable cost; Sol cost; net economic ROI; deployment champion; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — smart contract security vulnerability audit is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-claude-fable-5-vs-gpt-5-6-sol-m2-r2complex pharmaceutical patent claims analysis | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=complex pharmaceutical patent claims analysis; domain task; error impact value; Fable cost; Sol cost; net economic ROI; deployment champion; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — complex pharmaceutical patent claims analysis is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-claude-fable-5-vs-gpt-5-6-sol-m2-r3autonomous trading compliance verification | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=autonomous trading compliance verification; domain task; error impact value; Fable cost; Sol cost; net economic ROI; deployment champion; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — autonomous trading compliance verification is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-claude-fable-5-vs-gpt-5-6-sol-m2-r4critical infrastructure failure triage | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=critical infrastructure failure triage; domain task; error impact value; Fable cost; Sol cost; net economic ROI; deployment champion; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — critical infrastructure failure triage has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
batch64-claude-fable-5-vs-gpt-5-6-sol-m2-r5unbounded loop runaway circuit breaker | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=unbounded loop runaway circuit breaker; domain task; error impact value; Fable cost; Sol cost; net economic ROI; deployment champion; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unbounded loop runaway circuit breaker is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-claude-fable-5-vs-gpt-5-6-sol-m2-r6unverified tool execution risk | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=unverified tool execution risk; domain task; error impact value; Fable cost; Sol cost; net economic ROI; deployment champion; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unverified tool execution risk is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
First-party provenance: Anthropic Claude documentation; verification date 2026-09-07. Missing or conflicting joins fail closed.
Autonomous software engineering dual-canary audit framework
Frozen Batch 64 scenario board. Formula / deterministic rule: canary_spend = dual_runs * (fable_cost + sol_cost); consensus determines production cutover Boundary: Owns dual-run evaluation framework across top frontier architectures.
| Frozen scenario / field ID | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch64-claude-fable-5-vs-gpt-5-6-sol-m3-r150 automated complex refactoring pull requests | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=50 automated complex refactoring pull requests; evaluation workload; Fable 5 spend; Sol spend; dual-run budget; consensus rate; cutover status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 50 automated complex refactoring pull requests is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-claude-fable-5-vs-gpt-5-6-sol-m3-r2200 architecture design proofs | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=200 architecture design proofs; evaluation workload; Fable 5 spend; Sol spend; dual-run budget; consensus rate; cutover status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 200 architecture design proofs is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-claude-fable-5-vs-gpt-5-6-sol-m3-r3500 comprehensive security reviews | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=500 comprehensive security reviews; evaluation workload; Fable 5 spend; Sol spend; dual-run budget; consensus rate; cutover status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 500 comprehensive security reviews is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-claude-fable-5-vs-gpt-5-6-sol-m3-r41K integration bug root-cause analyses | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=1K integration bug root-cause analyses; evaluation workload; Fable 5 spend; Sol spend; dual-run budget; consensus rate; cutover status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 1K integration bug root-cause analyses is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-claude-fable-5-vs-gpt-5-6-sol-m3-r5consensus agreement threshold (>95%) | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=consensus agreement threshold (>95%); evaluation workload; Fable 5 spend; Sol spend; dual-run budget; consensus rate; cutover status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — consensus agreement threshold (>95%) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-claude-fable-5-vs-gpt-5-6-sol-m3-r6divergent architectural recommendation resolution | pair=claude-fable-5 vs gpt-5.6-sol; provider=Anthropic / OpenAI; hostA=api.anthropic.com; hostB=api.openai.com; surfaceA=Anthropic Messages API; surfaceB=OpenAI Responses API; requested/effective IDs=claude-fable-5,gpt-5.6-sol; scenario=divergent architectural recommendation resolution; evaluation workload; Fable 5 spend; Sol spend; dual-run budget; consensus rate; cutover status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — divergent architectural recommendation resolution is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
First-party provenance: OpenAI rate limits; verification date 2026-09-07. Missing or conflicting joins fail closed.
Method and limitations: formulas are deterministic; observed and assumed inputs are labeled; no missing provider, host, account, region, realm, alias, snapshot, revision, weight, artifact, control, tool, modality, workload, rate-period, timestamp, or result is transferred. Run the claude-fable-5-vs-gpt-5-6-sol Batch 64 scenario →
How do Claude Fable 5 and GPT-5.6 Sol compare on specs?
| Claude Fable 5 | GPT-5.6 Sol | |
|---|---|---|
| Price (input) | $10.00/M | $4.00/M ✓ |
| Price (output) | $50.00/M | $20.00/M ✓ |
| Blended price | $20.00/M | $8.00/M ✓ |
| Context window | 1,000,000 tokens | 1,000,000 tokens |
| Max output | 128,000 tokens | 128,000 tokens |
| Modalities | text, vision | text, vision |
| Reasoning mode | Yes | Yes |
| Released | 2026-05 | 2026-06 |
| Speed | 41 t/s | 44 t/s ✓ |
How much do Claude Fable 5 and GPT-5.6 Sol cost at scale?
| Tokens / month | Claude Fable 5 | GPT-5.6 Sol | Delta |
|---|---|---|---|
| 1,000,000 | $20.00 | $8.00 | $12.00 (2.5×) |
| 10,000,000 | $200.00 | $80.00 | $120.00 (2.5×) |
| 100,000,000 | $2000.00 | $800.00 | $1200.00 (2.5×) |
Choose Claude Fable 5 if…
- ✓Most capable widely-released Claude
- ✓1M-token context
- ✓Extended-thinking mode for hard reasoning
- ✓The most demanding reasoning and long-horizon agentic work.
Choose GPT-5.6 Sol if…
- ✓Strongest OpenAI model for agentic, long-horizon coding
- ✓Deep reasoning mode for multi-step planning
- ✓Native vision input and 1M context
- ✓Complex, multi-step professional and coding work where accuracy matters more than cost.
Run this exact matchup right now
Send the same prompt to Claude Fable 5 and GPT-5.6 Sol side by side and see the outputs yourself.
Try Claude Fable 5 vs GPT-5.6 Sol FreeWhat are common questions about Claude Fable 5 and GPT-5.6 Sol?
Is Claude Fable 5 cheaper than GPT-5.6 Sol?
GPT-5.6 Sol is cheaper, at $8.00 per million blended tokens vs $20.00 for Claude Fable 5.
Which has the bigger context window, Claude Fable 5 or GPT-5.6 Sol?
Both models support 1,000,000 tokens of context.
Can Claude Fable 5 replace GPT-5.6 Sol for coding?
Both are viable for coding. Most capable widely-released Claude (Claude Fable 5) vs Strongest OpenAI model for agentic, long-horizon coding (GPT-5.6 Sol) — pick based on which strength matters more for your workload.
Which is faster, Claude Fable 5 or GPT-5.6 Sol?
GPT-5.6 Sol is faster: 44 t/s vs 41 t/s, measured on our speed benchmarks.
Neither of these? See Claude Fable 5 alternatives or GPT-5.6 Sol alternatives.
What related comparisons help choose between Claude Fable 5 and GPT-5.6 Sol?
Claude Fable 5 pricingGPT-5.6 Sol pricingvs Claude Opus 4.8vs Claude Sonnet 5vs GPT-4ovs Claude Opus 4.8Premium model tests
Pricing verified 2026-08-14. Specs verified 2026-08-14.