kyle-sexton · Oct 26, 2026 · Oct 26, 2026 · Oct 26, 2026 · Oct 26, 2026 · Oct 26, 2026
diff --git a/.changes/playbooks/feat-4346-fable-5-1-regeneration-4672d98d.md b/.changes/playbooks/feat-4346-fable-5-1-regeneration-4672d98d.md
@@ -0,0 +1,15 @@
+---
+bump: minor
+---
+
+### Changed
+
+- **The fable-5 doctrine is Claude Fable 5.1's.** Every line of the skill body and its thirteen chapters was kept, rewritten or removed by a Fable 5.1 session, and the pack names Fable 5.1 as its author in the skill description, body, README, update skill and plugin description. The deltas the retired Fable 5.1 adaptation chapter carried now live in the owning chapters: tool-call batching on every round in `execution.md`, targeted edits and tests sized to the task in `execution.md`, progress lines, whole-turn closing messages, plain-clause density and quotation marking in `communication.md`, the low-effort recall rule in `calibration.md`, and the lead-keeps-working pointer in `orchestration.md`, each with a pointer record. The verification chapter gains an above-the-floor move: an independent oracle (reference implementation, brute-force cross-check, or spec-driven fuzzer) run on randomized inputs where a specification allows one ([#4346](https://github.com/melodic-software/claude-code-plugins/issues/4346)).
+- **Meta-rule 3 routes from Fable 5.1.** A Fable 5.1 session reads no adaptation chapter, and neither does a Fable 5 session, since the documented Fable 5.1 differences are matters of degree in tendencies the doctrine already counters and none reverses a Fable 5 behavior; the record beside it names the guide and its recheck trigger. The current-model list is Opus 5.5, Sonnet 5.5 and Haiku 5.5; the fallback-only list is unchanged. The Fable 5 system card citation is dropped: model-config owns fallback behavior. The six remaining adaptation chapters are baselined against the new author, and the Opus 4.8 chapter's Fable-behavior pointers move to the Fable 5.1 guide where it has the section.
+- **Three verification records re-derived.** The calibration chapter's thinking-table pointer, the context-economy chapter's keep-all thinking record (now against Claude Code 2.1.310) and every record in the API chapter carry fresh as-of dates from raw-markdown re-reads.
+- **The API chapter widens to request assembly.** `reference/prompt-caching.md` gains "Conversation history", "Forced tool use" and "Effort against model choice" sections, taking the API-side rows the retired chapter held.
+- The fable-5 evals assert the new routing: a Fable 5.1 session and a Fable 5 session each read no adaptation chapter; the Sonnet 5.5 and Haiku 5.5 routing cases no longer name the retired file. Eleven `claude plugin eval` outcome cases and a frozen trigger probe set are added for the rewrite measurement.
+
+### Removed
+
+- `reference/model-adaptation/fable-5-1.md`. Nothing in it survives only as a patch over the doctrine; its sections were folded, moved or dropped as the Changed entry lists.
diff --git a/docs/catalog.md b/docs/catalog.md
@@ -1,6 +1,6 @@
 # Plugin catalog
 
-The generated per-category plugin catalog: the block between the markers below is generated from the
+This is the generated per-category plugin catalog. The block between the markers below is generated from the
 plugin manifests and kept in sync by CI. Never hand-edit it; the category vocabulary is owned by
 [`docs/catalog-taxonomy.md`](catalog-taxonomy.md).
 
@@ -85,7 +85,7 @@ plugin manifests and kept in sync by CI. Never hand-edit it; the category vocabu
 ## Claude Code
 
 - [`desktop-notification`](../plugins/desktop-notification): Alert you when Claude Code needs input: an audible terminal bell, an OSC 9 terminal notification, and an OS-native toast (macOS/Linux) on permission and idle prompts.
-- [`playbooks`](../plugins/playbooks): Doctrine and knowledge playbooks as on-demand skills: boris (Boris Cherny's Claude Code workflow tips, howborisusesclaudecode.com), skill-authoring (Anthropic's internal skill-authoring playbook), fable-5 (Claude Fable 5's operating doctrine, self-authored), and repo-sweep (runs a catalog of hygiene skills through a repository one commit per step). boris and skill-authoring vendor a verbatim upstream baseline; /playbooks:update drift-checks and syncs them (maintainers).
+- [`playbooks`](../plugins/playbooks): Doctrine and knowledge playbooks as on-demand skills: boris (Boris Cherny's Claude Code workflow tips, howborisusesclaudecode.com), skill-authoring (Anthropic's internal skill-authoring playbook), fable-5 (Claude Fable 5.1's operating doctrine, self-authored), and repo-sweep (runs a catalog of hygiene skills through a repository one commit per step). boris and skill-authoring vendor a verbatim upstream baseline; /playbooks:update drift-checks and syncs them (maintainers).
 - [`harness-config`](../plugins/harness-config): Configuration health for a repo's Claude Code: audit (settings, .mcp.json, hooks, plugins, permission drift), audit-automation-gaps, audit-permission-grants, audit-permission-state (effective rules with provenance), draft-auto-mode-rules (prints an autoMode block), audit-instructions (instructions the model no longer needs, conflicts), audit-prompting-postures, audit-pass (one ordered, resumable pass), unhobble (strip instructions, re-add what evidence earns), and setup.
 - [`harness-memory`](../plugins/harness-memory): Keeps a repo's Claude Code memory layer healthy, against criteria from official Claude Code docs. audit checks CLAUDE.md, a root AGENTS.md, CLAUDE.local.md, .claude/rules/, and auto-memory for structure, size, placement, and index integrity, with scripted and judgment checks. stateless inspects, disables, and (after confirmation) purges Claude-written auto memory across settings scopes. Whether instruction text fits the current model belongs to harness-config.
 - [`harness-ops`](../plugins/harness-ops): Claude Code operations: audit-skill-visibility (skills the listing budget hides), inventory (every invocable surface), audit-install-state, audit-performance (slowness), audit-mod-posture (mods and the guard), audit-native-overlap (skills duplicating built-ins), observability (telemetry), known-issues, changelog, behavior-probes, prerequisites, check, machine-profile, plugins (update the fleet), morning-brief, lanes (background loop sessions), setup. Plus opt-in hook event logs.

diff --git a/docs/native-surfaces.md b/docs/native-surfaces.md
@@ -607,7 +607,7 @@ and when. See [`docs/conventions/native-references/`](conventions/native-referen
 - **Evidence:**
   - binary extraction 2026-09-09 (claude.exe 2.1.263): registerClaudeApiSkill present; subcommand array cost-optimize, migrate, managed-agents-onboard, prompt-audit, upgrade, build-eval, hillclimb
   - platform docs claude-api-skill page (fetched 2026-09-09): bundled with Claude Code and published in the open-source skills repository
-  - reference/model-adaptation/fable-5-1.md standing rule: 'this chapter carries no model ID, price, or limit. Resolve the current details through the claude-api skill at the moment of use'
+  - reference/prompt-caching.md standing rule: 'Current prices, model IDs, limits and TTL values resolve through the pricing page or the bundled claude-api skill at the moment of use; this chapter carries practices, not numbers'
   - reference/prompt-caching.md 'Automation' bullet cites cost-optimize behind the presence gate
 - **Observation:** extraction: extracted from binary 2.1.263 at node_modules/@anthropic-ai/claude-code/bin/claude.exe (registerClaudeApiSkill string plus subcommand array); bulk registrar enumeration was broken at this build, so this row's evidence is the targeted extraction, not the inventory JSON (2026-09-09)
 - **Recheck trigger:** a Claude Code release changes the bundled claude-api skill's subcommand set or moves it between bundled and marketplace distribution (verified 2026-09-11)

diff --git a/docs/native-surfaces/records.json b/docs/native-surfaces/records.json
@@ -734,7 +734,7 @@
       "evidence": [
         "binary extraction 2026-09-09 (claude.exe 2.1.263): registerClaudeApiSkill present; subcommand array cost-optimize, migrate, managed-agents-onboard, prompt-audit, upgrade, build-eval, hillclimb",
         "platform docs claude-api-skill page (fetched 2026-09-09): bundled with Claude Code and published in the open-source skills repository",
-        "reference/model-adaptation/fable-5-1.md standing rule: 'this chapter carries no model ID, price, or limit. Resolve the current details through the claude-api skill at the moment of use'",
+        "reference/prompt-caching.md standing rule: 'Current prices, model IDs, limits and TTL values resolve through the pricing page or the bundled claude-api skill at the moment of use; this chapter carries practices, not numbers'",
         "reference/prompt-caching.md 'Automation' bullet cites cost-optimize behind the presence gate"
       ],
       "observation": {

diff --git a/docs/plugin-philosophy.md b/docs/plugin-philosophy.md
@@ -208,7 +208,7 @@ Never degrade a name to dodge a built-in command: plugin skills are namespaced a
 with other levels. When a name matches a built-in, the bare token still belongs to the built-in; the
 namespaced form is the plugin skill's only command.
 
-Resolution settled, **display** follows from it. We rely on a plugin skill keeping its plugin
+With name resolution settled, **display** follows from it. We rely on a plugin skill keeping its plugin
 prefix in autocomplete whether or not it declares `name`. A version-dependent display quirk for a
 `name` that carries the plugin's own prefix is moot under this doctrine, because the only
 sanctioned value is the bare directory name.
@@ -1073,7 +1073,7 @@ collaboration, so it carries the presence-gate-plus-fallback shape
 ([seam phrasing](conventions/seam-phrasing/README.md)) at each site that instructs it; an advisor
 plugin external to this marketplace is never a manifest dependency. Invocation mechanics such as
 synchronous waiting, diff-base selection, and which artifacts a surface can judge are the advisor
-plugin's own documentation's concern: a checkpoint site names the capability and the fallback,
+plugin's own documentation's concern. A checkpoint site names the capability and the fallback,
 never the advisor's command flags, which drift against the surface their owner evolves.
 
 What does not need it: deterministic gates (a script's pass/fail cannot be biased by context, so prefer
@@ -1259,7 +1259,7 @@ An implementation phase the plan routes `sonnet` as well-scoped drops one tier,
 `implementation:scoped-implementer` at `medium` effort, the [effort floor](#effort-floor); unrouted
 or complex phases stay on `implementation:implementer` at the strong tier.
 
-The heavy default must be explicit: every agent definition in this repository pins `model`, because an agent that omits it
+The heavy default must be explicit. Every agent definition in this repository pins `model`, because an agent that omits it
 falls through the harness's resolution order and, on a machine with no consumer default, runs on
 the main conversation's model. Consumers hold one global fallback knob, `CLAUDE_CODE_SUBAGENT_MODEL`,
 set through the settings `env` map. We rely on it ranking below both the per-invocation `model`
@@ -1487,9 +1487,9 @@ same depth on two models):
   buys).
 - **Sweep model and effort together before raising either.** A lane outgrowing its level tests the
   newer model at lower effort before pinning the old one higher, on its own evals. Cross-model
-  economics and the flat-curve reading live in the fable-5 pack's model-adaptation chapter for the
-  newer model (`plugins/playbooks/reference/model-adaptation/fable-5-1.md`, "Cross-model effort
-  economics"); current prices resolve through the `claude-api` skill at decision time.
+  economics and the flat-curve reading live in the fable-5 pack's API chapter
+  (`plugins/playbooks/reference/prompt-caching.md`, "Effort against model choice"); current prices
+  resolve through the `claude-api` skill at decision time.
 - **Effort is the first lever in either direction; steering prose is the second.** We set the
   level to fit the lane's work and add prose only where that level still falls short (Pointer:
   for why, see

diff --git a/docs/skill-cheat-sheet.md b/docs/skill-cheat-sheet.md
@@ -309,7 +309,7 @@ owned by [docs/catalog-taxonomy.md](catalog-taxonomy.md).
 | [`/overengineering:delta`](../plugins/overengineering/skills/delta/SKILL.md) | `overengineering` | Re-run the enforcement-surface audit and report only what moved since the last run |
 | [`/overengineering:justify`](../plugins/overengineering/skills/justify/SKILL.md) | `overengineering` | Make one artifact, or one proposal before it is built, justify its existence on evidence |
 | [`/playbooks:boris`](../plugins/playbooks/skills/boris/SKILL.md) | `playbooks` | Boris Cherny's Claude Code workflow tips across 130 sections |
-| [`/playbooks:fable-5`](../plugins/playbooks/skills/fable-5/SKILL.md) | `playbooks` | Fable 5's operating doctrine loaded as standing session instructions |
+| [`/playbooks:fable-5`](../plugins/playbooks/skills/fable-5/SKILL.md) | `playbooks` | Fable 5.1's operating doctrine loaded as standing session instructions |
 | [`/playbooks:repo-sweep`](../plugins/playbooks/skills/repo-sweep/SKILL.md) | `playbooks` | Run the hygiene skill catalog through one repo, one PR, one commit per step |
 | [`/playbooks:skill-authoring`](../plugins/playbooks/skills/skill-authoring/SKILL.md) | `playbooks` | Anthropic's internal skill-authoring playbook and patterns |
 | [`/playgrounds:use`](../plugins/playgrounds/skills/use/SKILL.md) | `playgrounds` | Route playground requests to the first-party plugin, or install it, with recipes and guidance |

diff --git a/docs/upstream/claudedevs-cost-performance.md b/docs/upstream/claudedevs-cost-performance.md
@@ -186,7 +186,7 @@ tooling.
 | Topic | Ours | Verdict | Pointer | As of |
 |---|---|---|---|---|
 | Effort miscalibration in both directions | PLUGIN-PHILOSOPHY Effort tiers; opus-5 chapter overthinking guidance; fable-5-1 low-effort recall caveat | COVERED, plus a sharpening ADOPT (decided 2026-09-10). Explore evidence re-verified 2026-09-09. Work item: fold the article's two sharpest phrasings on miscalibration, in our words, into the existing surfaces | [How effort works](https://platform.claude.com/docs/en/build-with-claude/effort#how-effort-works) | 2026-09-09 |
-| A stronger model at lower effort | Nowhere; adaptation chapters deliberately carry no pricing | ADOPT (decided 2026-09-10). Land as a pricing-free section in the fable-5-1 model-adaptation chapter plus a one-line pointer in PLUGIN-PHILOSOPHY Effort tiers; numbers cited vendor-reported; pricing stays pointer-resolved through the claude-api skill | [Compare models on cost per task](https://platform.claude.com/docs/en/about-claude/models/optimizing-for-cost-and-intelligence#compare-models-on-cost-per-task) and [Model pricing](https://platform.claude.com/docs/en/about-claude/pricing#model-pricing) | 2026-09-09 |
+| A stronger model at lower effort | Nowhere; adaptation chapters deliberately carry no pricing | ADOPT (decided 2026-09-10). Land as a pricing-free section in the fable-5-1 model-adaptation chapter plus a one-line pointer in PLUGIN-PHILOSOPHY Effort tiers; numbers cited vendor-reported; pricing stays pointer-resolved through the claude-api skill. Landing moved 2026-10-26 to `plugins/playbooks/reference/prompt-caching.md` "Effort against model choice" when that chapter was retired (#4346) | [Compare models on cost per task](https://platform.claude.com/docs/en/about-claude/models/optimizing-for-cost-and-intelligence#compare-models-on-cost-per-task) and [Model pricing](https://platform.claude.com/docs/en/about-claude/pricing#model-pricing) | 2026-09-09 |
 | Effort sweeps on a non-saturated eval | `evals` plugin has zero effort content | ADOPT (decided 2026-09-10). Land as an effort-axis note in the evals plugin citing the bundled hillclimb per the Lane M posture, pointing at its published guide (finding 1) | [Tune effort](https://platform.claude.com/docs/en/about-claude/models/optimizing-for-cost-and-intelligence#tune-effort) | 2026-09-09 |
 | Effort changes mid-conversation and the cache | PLUGIN-PHILOSOPHY cache caveat + criteria I17-b carry the session-side version | COVERED session-side (decided 2026-09-10). The API-side model list is read at the pointer only inside whatever T1/T3 adoptions get written, per the Lane M beta posture; no separate surface | [Per-message effort (beta)](https://platform.claude.com/docs/en/build-with-claude/effort#change-effort-mid-conversation-beta) | 2026-09-09 |
 
@@ -227,7 +227,8 @@ of this file's branch records the commits):
 1. New playbooks prompt-caching reference chapter (T1 chapter rows + T4 Batch/Admin/
    cost-optimize-mention/output-bounding rows), beta qualifiers carried.
 2. fable-5-1 model-adaptation chapter: pricing-free cross-model economics section, plus a
-   one-line pointer in PLUGIN-PHILOSOPHY Effort tiers (T3).
+   one-line pointer in PLUGIN-PHILOSOPHY Effort tiers (T3). Moved 2026-10-26 to
+   `plugins/playbooks/reference/prompt-caching.md` "Effort against model choice" (#4346).
 3. evals plugin effort-axis note citing the bundled hillclimb (T3).
 4. Sharpening pass folding the article's two phrasings into the existing effort surfaces
    (T3).

diff --git a/plugins/playbooks/.claude-plugin/plugin.json b/plugins/playbooks/.claude-plugin/plugin.json
@@ -1,7 +1,7 @@
 {
   "name": "playbooks",
   "version": "0.24.5",
-  "description": "Doctrine and knowledge playbooks as on-demand skills: boris (Boris Cherny's Claude Code workflow tips, howborisusesclaudecode.com), skill-authoring (Anthropic's internal skill-authoring playbook), fable-5 (Claude Fable 5's operating doctrine, self-authored), and repo-sweep (runs a catalog of hygiene skills through a repository one commit per step). boris and skill-authoring vendor a verbatim upstream baseline; /playbooks:update drift-checks and syncs them (maintainers).",
+  "description": "Doctrine and knowledge playbooks as on-demand skills: boris (Boris Cherny's Claude Code workflow tips, howborisusesclaudecode.com), skill-authoring (Anthropic's internal skill-authoring playbook), fable-5 (Claude Fable 5.1's operating doctrine, self-authored), and repo-sweep (runs a catalog of hygiene skills through a repository one commit per step). boris and skill-authoring vendor a verbatim upstream baseline; /playbooks:update drift-checks and syncs them (maintainers).",
   "author": {
     "name": "Melodic Software",
     "email": "info@melodicsoftware.com"