diff --git a/FEATURES.md b/FEATURES.md
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+# FEATURES
+
+This file is the human-oriented capability map for Singularity Foundry.
+
+It is intentionally not the source of truth for schemas or tool parameters. Use it to answer:
+
+- what SF can do today
+- which surfaces are first-class versus experimental
+- where a capability lives in the system
+
+For exact contracts, use:
+
+- `README.md` for product positioning and user docs
+- `packages/mcp-server/src/workflow-tools.ts` for workflow tool schemas
+- `src/resources/extensions/sf/` for planning/state-machine behavior
+- `src/resources/extensions/*/extension-manifest.json` for extension inventory
+- `packages/pi-ai/src/` for provider and model registry behavior
+
+## Core Product Shape
+
+SF is a coding-agent application built around:
+
+- a milestone → slice → task planning hierarchy
+- a DB-backed workflow state machine
+- MCP-accessible workflow mutations and readers
+- extension-based capability loading
+- multi-provider model routing
+- interactive and autonomous execution modes
+
+The core planning/runtime loop is:
+
+1. discuss / research / align
+2. plan milestone
+3. plan slice
+4. execute task-by-task
+5. verify gates
+6. summarize and validate
+7. reassess roadmap and continue
+
+## Planning And Ceremony Capabilities
+
+### Milestone planning
+
+SF supports milestone plans with:
+
+- milestone title, vision, and slice breakdown
+- success criteria and definition of done
+- key risks and proof strategy
+- verification contract, integration, operational, and UAT sections
+- requirement coverage and boundary-map support
+
+### Vision meeting
+
+Milestones can carry a weighted `visionMeeting` that captures:
+
+- `pm`
+- `userAdvocate`
+- `customerPanel`
+- `business`
+- `researcher`
+- `deliveryLead`
+- `partner`
+- `combatant`
+- `architect`
+- `moderator`
+- weighted synthesis
+- confidence by area
+- recommended route: `discussing`, `researching`, or `planning`
+
+This is the top-level roadmap/vision alignment ceremony.
+
+### Slice planning
+
+Slices support:
+
+- goal
+- success criteria
+- proof level
+- integration closure
+- observability impact
+- ordered task plans with expected files, verification, inputs, outputs
+
+### Adversarial review
+
+Slice planning supports first-class adversarial review with:
+
+- `partner`
+- `combatant`
+- `architect`
+
+This is treated as required planning structure, not commentary.
+
+### Planning meeting
+
+Slices also support a structured planning meeting with:
+
+- trigger
+- `pm`
+- `researcher`
+- `partner`
+- `combatant`
+- `architect`
+- `moderator`
+- recommended route
+- confidence summary
+
+This is the narrower execution-readiness ceremony.
+
+### Replanning
+
+When a blocker invalidates a slice plan, SF supports slice replanning with:
+
+- blocker task + blocker description
+- what changed
+- updated tasks
+- removed tasks
+- updated slice-level planning fields
+- updated adversarial review
+- updated planning meeting
+
+Replan state is preserved in DB and re-rendered into plan artifacts.
+
+## Workflow State Machine
+
+The SF workflow engine derives and enforces states including:
+
+- `pre-planning`
+- `needs-discussion`
+- `planning`
+- `evaluating-gates`
+- `executing`
+- `summarizing`
+- `validating-milestone`
+- `completing-milestone`
+- `replanning-slice`
+- `complete`
+- `blocked`
+
+Important properties:
+
+- execution readiness is gated by artifact completeness, not just file existence
+- meeting/ceremony data participates in readiness
+- blocked/dependency-aware progression is built in
+- routed-back plans stay in planning instead of pretending to be ready
+
+## Artifact And Persistence Capabilities
+
+SF persists workflow state in multiple synchronized forms:
+
+- SQLite DB (`.sf/sf.db`)
+- markdown planning artifacts
+- state manifest snapshots
+- worktree DB reconciliation state
+- workflow events
+
+Planning/ceremony state now survives across:
+
+- DB writes
+- markdown rendering
+- pure projection rendering
+- manifest export / restore
+- worktree reconciliation
+- state derivation and execution gating
+- slice replanning
+
+## Execution Capabilities
+
+SF can execute work in:
+
+- interactive mode
+- headless mode
+- auto mode
+- parallel / multi-worker orchestration
+
+Execution-related features include:
+
+- task-sized dispatch units
+- crash recovery and lock-aware state
+- timeout supervision
+- worktree isolation
+- per-unit summaries and milestone completion flow
+- roadmap reassessment after completed slices
+
+## MCP And Workflow Tooling
+
+The workflow layer is exposed over MCP, including mutation/read paths for:
+
+- milestone planning
+- slice planning
+- slice replanning
+- task completion
+- slice completion
+- milestone validation
+- milestone completion
+- roadmap reassessment
+- gate results
+- summary save/read flows
+
+This makes SF usable from external clients without relying on slash-command prompt tricks.
+
+## Search And Research Capabilities
+
+SF has dedicated web/research support via onboarding, auth storage, and extension flows.
+
+Currently supported first-class web-search providers include:
+
+- `brave`
+- `tavily`
+- `serper`
+- `exa`
+
+Other search/research surfaces include:
+
+- Ollama native web search / fetch integration
+- Google search extension
+- Context7 extension for library/documentation retrieval
+- Jina-backed content extraction paths where configured
+
+The search stack is available to automatic workflows, not only slash commands.
+
+## Subagents And Background Work
+
+SF includes subagent capabilities via the `subagent` extension, including:
+
+- delegated agent runs
+- background subagent jobs
+- await/join behavior
+- cancellation
+- workflow-driven use rather than only interactive commands
+
+This is useful for automatic coding flows and wave-based task execution.
+
+## Extension Inventory
+
+Bundled extension families currently include:
+
+- `sf` — workflow engine, planning/state/artifacts
+- `search-the-web`
+- `subagent`
+- `async-jobs`
+- `bg-shell`
+- `browser-tools`
+- `context7`
+- `genai-proxy`
+- `google-search`
+- `ollama`
+- `remote-questions`
+- `slash-commands`
+- `mac-tools`
+- `ttsr`
+- `universal-config`
+- `voice`
+
+These are not all equal in product importance, but they are real shipped extension surfaces.
+
+## Model And Provider Capabilities
+
+SF supports multi-provider model routing across built-in and custom providers.
+
+Notable supported/known providers in the current runtime and registry surface include:
+
+- `anthropic`
+- `anthropic-vertex`
+- `openai`
+- `azure-openai-responses`
+- `openai-codex`
+- `google`
+- `google-gemini-cli`
+- `google-vertex`
+- `mistral`
+- `amazon-bedrock`
+- `ollama`
+- `ollama-cloud`
+- `openrouter`
+- `groq`
+- `xai`
+- `github-copilot`
+- `zai`
+- `minimax`
+- `minimax-cn`
+- `kimi-coding`
+- `xiaomi`
+- `custom-openai`
+
+Recent/custom provider support in this tree also includes:
+
+- `zai` / GLM-family routing
+- `xiaomi` / MiMo Anthropic-compatible endpoint
+- `kimi-coding` / dedicated coding endpoint
+- `minimax` Anthropic-compatible support
+
+## Onboarding And Auth
+
+Onboarding currently supports:
+
+- LLM provider selection
+- OAuth or API-key based provider setup where applicable
+- local Ollama detection
+- web-search provider setup
+- remote questions setup
+- tool-key collection for selected extensions
+
+This is a real product capability, not just a doc path.
+
+## Recovery, Reliability, And Operational Features
+
+SF includes real operational hardening around:
+
+- manifest bootstrapping and restore
+- worktree/DB reconciliation
+- cache invalidation around plan parsing
+- atomic writes and TOCTOU protection
+- gate-aware progression
+- idle/timeout handling
+- scoped recovery for auto mode
+
+## UI And Interaction Surfaces
+
+SF is not only a CLI. The repo also carries:
+
+- TUI support
+- web interface support
+- VS Code extension support
+- MCP server support
+
+So the product surface is broader than “terminal prompt framework.”
+
+## What This File Does Not Try To Be
+
+This file does not list:
+
+- every MCP tool parameter
+- every extension command
+- every model ID
+- every preference flag
+- every internal DB column
+
+Those should stay close to code or generated inventories.
+
+## Generated Inventory
+
+The section below is generated from source declarations so this overview can stay concise while exact inventories remain refreshable.
+
+<!-- GENERATED_FEATURE_INVENTORY_START -->
+
+### Workflow Tools
+
+Generated from `packages/mcp-server/src/workflow-tools.ts`.
+
+- `sf_complete_milestone`
+- `sf_complete_slice`
+- `sf_complete_task`
+- `sf_decision_save`
+- `sf_generate_milestone_id`
+- `sf_journal_query`
+- `sf_milestone_complete`
+- `sf_milestone_generate_id`
+- `sf_milestone_status`
+- `sf_milestone_validate`
+- `sf_plan_milestone`
+- `sf_plan_slice`
+- `sf_plan_task`
+- `sf_reassess_roadmap`
+- `sf_replan_slice`
+- `sf_requirement_save`
+- `sf_requirement_update`
+- `sf_roadmap_reassess`
+- `sf_save_decision`
+- `sf_save_gate_result`
+- `sf_save_requirement`
+- `sf_skip_slice`
+- `sf_slice_complete`
+- `sf_slice_replan`
+- `sf_summary_save`
+- `sf_task_complete`
+- `sf_task_plan`
+- `sf_update_requirement`
+- `sf_validate_milestone`
+
+### Bundled Extensions
+
+Generated from `src/resources/extensions/*/extension-manifest.json`.
+
+- `async-jobs` — [extension-manifest.json](src/resources/extensions/async-jobs/extension-manifest.json)
+- `bg-shell` — [extension-manifest.json](src/resources/extensions/bg-shell/extension-manifest.json)
+- `browser-tools` — [extension-manifest.json](src/resources/extensions/browser-tools/extension-manifest.json)
+- `context7` — [extension-manifest.json](src/resources/extensions/context7/extension-manifest.json)
+- `genai-proxy` — [extension-manifest.json](src/resources/extensions/genai-proxy/extension-manifest.json)
+- `google-search` — [extension-manifest.json](src/resources/extensions/google-search/extension-manifest.json)
+- `mac-tools` — [extension-manifest.json](src/resources/extensions/mac-tools/extension-manifest.json)
+- `ollama` — [extension-manifest.json](src/resources/extensions/ollama/extension-manifest.json)
+- `remote-questions` — [extension-manifest.json](src/resources/extensions/remote-questions/extension-manifest.json)
+- `search-the-web` — [extension-manifest.json](src/resources/extensions/search-the-web/extension-manifest.json)
+- `sf` — [extension-manifest.json](src/resources/extensions/sf/extension-manifest.json)
+- `slash-commands` — [extension-manifest.json](src/resources/extensions/slash-commands/extension-manifest.json)
+- `subagent` — [extension-manifest.json](src/resources/extensions/subagent/extension-manifest.json)
+- `ttsr` — [extension-manifest.json](src/resources/extensions/ttsr/extension-manifest.json)
+- `universal-config` — [extension-manifest.json](src/resources/extensions/universal-config/extension-manifest.json)
+- `voice` — [extension-manifest.json](src/resources/extensions/voice/extension-manifest.json)
+
+### Search Providers
+
+Generated from the `search-the-web` extension provider declarations.
+
+- `brave`
+- `exa`
+- `ollama`
+- `serper`
+- `tavily`
+
+### Known Model Providers
+
+Generated from `packages/pi-ai/src/types.ts` (`KnownProvider`).
+
+- `alibaba-coding-plan`
+- `alibaba-dashscope`
+- `amazon-bedrock`
+- `anthropic`
+- `anthropic-vertex`
+- `azure-openai-responses`
+- `cerebras`
+- `github-copilot`
+- `google`
+- `google-gemini-cli`
+- `google-vertex`
+- `groq`
+- `huggingface`
+- `kimi-coding`
+- `longcat`
+- `minimax`
+- `minimax-cn`
+- `mistral`
+- `ollama`
+- `ollama-cloud`
+- `openai`
+- `openai-codex`
+- `opencode`
+- `opencode-go`
+- `openrouter`
+- `vercel-ai-gateway`
+- `xai`
+- `xiaomi`
+- `zai`
+
+<!-- GENERATED_FEATURE_INVENTORY_END -->
diff --git a/scripts/generate-features-inventory.mjs b/scripts/generate-features-inventory.mjs
new file mode 100644
index 000000000..89ef516bb
--- /dev/null
+++ b/scripts/generate-features-inventory.mjs
@@ -0,0 +1,127 @@
+import { readFileSync, readdirSync, writeFileSync } from "node:fs";
+import { dirname, join, relative, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+const repoRoot = resolve(__dirname, "..");
+
+const featuresPath = join(repoRoot, "FEATURES.md");
+const workflowToolsPath = join(repoRoot, "packages", "mcp-server", "src", "workflow-tools.ts");
+const providersPath = join(repoRoot, "packages", "pi-ai", "src", "types.ts");
+const extensionsRoot = join(repoRoot, "src", "resources", "extensions");
+const searchToolPath = join(repoRoot, "src", "resources", "extensions", "search-the-web", "tool-search.ts");
+
+export const START = "<!-- GENERATED_FEATURE_INVENTORY_START -->";
+export const END = "<!-- GENERATED_FEATURE_INVENTORY_END -->";
+
+function uniqueSorted(values) {
+  return [...new Set(values)].sort((a, b) => a.localeCompare(b));
+}
+
+export function parseWorkflowToolNames() {
+  const src = readFileSync(workflowToolsPath, "utf8");
+  const matches = [...src.matchAll(/server\.tool\(\s*"([^"]+)"/g)].map((m) => m[1]);
+  return uniqueSorted(matches);
+}
+
+export function parseKnownProviders() {
+  const src = readFileSync(providersPath, "utf8");
+  const match = src.match(/export type KnownProvider =([\s\S]*?);/);
+  if (!match) throw new Error("Could not find KnownProvider in packages/pi-ai/src/types.ts");
+  const providers = [...match[1].matchAll(/"([^"]+)"/g)].map((m) => m[1]);
+  return uniqueSorted(providers);
+}
+
+export function parseBundledExtensions() {
+  const entries = readdirSync(extensionsRoot, { withFileTypes: true })
+    .filter((entry) => entry.isDirectory())
+    .map((entry) => entry.name)
+    .filter((name) => {
+      try {
+        const manifestPath = join(extensionsRoot, name, "extension-manifest.json");
+        readFileSync(manifestPath, "utf8");
+        return true;
+      } catch {
+        return false;
+      }
+    });
+  return uniqueSorted(entries);
+}
+
+export function parseSearchProviders() {
+  const src = readFileSync(searchToolPath, "utf8");
+  const providers = [
+    ...src.matchAll(/providers\.push\('([^']+)'\)/g),
+    ...src.matchAll(/provider\?: '([^']+)'/g),
+  ]
+    .map((m) => m[1])
+    .filter((p) => p !== "combosearch");
+  return uniqueSorted(providers);
+}
+
+function formatBullets(values, formatter = (value) => `- \`${value}\``) {
+  return values.map((value) => formatter(value)).join("\n");
+}
+
+export function buildSection() {
+  const workflowTools = parseWorkflowToolNames();
+  const extensions = parseBundledExtensions();
+  const searchProviders = parseSearchProviders();
+  const knownProviders = parseKnownProviders();
+
+  return [
+    "### Workflow Tools",
+    "",
+    "Generated from `packages/mcp-server/src/workflow-tools.ts`.",
+    "",
+    formatBullets(workflowTools),
+    "",
+    "### Bundled Extensions",
+    "",
+    "Generated from `src/resources/extensions/*/extension-manifest.json`.",
+    "",
+    formatBullets(
+      extensions,
+      (value) => `- \`${value}\` — [extension-manifest.json](${relative(repoRoot, join(extensionsRoot, value, "extension-manifest.json"))})`,
+    ),
+    "",
+    "### Search Providers",
+    "",
+    "Generated from the `search-the-web` extension provider declarations.",
+    "",
+    formatBullets(searchProviders),
+    "",
+    "### Known Model Providers",
+    "",
+    "Generated from `packages/pi-ai/src/types.ts` (`KnownProvider`).",
+    "",
+    formatBullets(knownProviders),
+    "",
+  ].join("\n");
+}
+
+export function updateFeaturesContent(features) {
+  const startIndex = features.indexOf(START);
+  const endIndex = features.indexOf(END);
+
+  if (startIndex === -1 || endIndex === -1 || endIndex < startIndex) {
+    throw new Error("FEATURES.md is missing generated inventory markers");
+  }
+
+  const before = features.slice(0, startIndex + START.length);
+  const after = features.slice(endIndex);
+  const section = `\n\n${buildSection()}`;
+  return `${before}${section}\n${after}`;
+}
+
+export function main() {
+  const features = readFileSync(featuresPath, "utf8");
+  const updated = updateFeaturesContent(features);
+  writeFileSync(featuresPath, updated);
+  process.stdout.write(`Updated ${relative(repoRoot, featuresPath)}\n`);
+}
+
+if (process.argv[1] && resolve(process.argv[1]) === __filename) {
+  main();
+}
diff --git a/src/tests/features-inventory-generator.test.ts b/src/tests/features-inventory-generator.test.ts
new file mode 100644
index 000000000..31eeaa324
--- /dev/null
+++ b/src/tests/features-inventory-generator.test.ts
@@ -0,0 +1,68 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+import {
+  START,
+  END,
+  buildSection,
+  parseBundledExtensions,
+  parseKnownProviders,
+  parseSearchProviders,
+  parseWorkflowToolNames,
+  updateFeaturesContent,
+} from "../../scripts/generate-features-inventory.mjs";
+
+test("features inventory generator surfaces expected workflow tool, extension, search, and provider inventories", () => {
+  const workflowTools = parseWorkflowToolNames();
+  const extensions = parseBundledExtensions();
+  const searchProviders = parseSearchProviders();
+  const knownProviders = parseKnownProviders();
+
+  assert.ok(workflowTools.includes("sf_plan_milestone"));
+  assert.ok(workflowTools.includes("sf_replan_slice"));
+  assert.ok(workflowTools.includes("sf_task_complete"));
+
+  assert.ok(extensions.includes("sf"));
+  assert.ok(extensions.includes("search-the-web"));
+  assert.ok(extensions.includes("subagent"));
+
+  assert.deepEqual(searchProviders, ["brave", "exa", "ollama", "serper", "tavily"]);
+
+  assert.ok(knownProviders.includes("mistral"));
+  assert.ok(knownProviders.includes("zai"));
+  assert.ok(knownProviders.includes("kimi-coding"));
+  assert.ok(knownProviders.includes("xiaomi"));
+});
+
+test("features inventory generator injects a rendered appendix between markers", () => {
+  const original = [
+    "# FEATURES",
+    "",
+    "Intro text.",
+    "",
+    START,
+    END,
+    "",
+  ].join("\n");
+
+  const updated = updateFeaturesContent(original);
+  const generated = buildSection();
+
+  assert.match(updated, new RegExp(`${START.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")}\\n\\n### Workflow Tools`));
+  assert.match(updated, /### Bundled Extensions/);
+  assert.match(updated, /### Search Providers/);
+  assert.match(updated, /### Known Model Providers/);
+  assert.match(updated, /- `sf_plan_milestone`/);
+  assert.match(updated, /- `search-the-web` — \[extension-manifest\.json]/);
+  assert.match(updated, /- `brave`/);
+  assert.match(updated, /- `xiaomi`/);
+  assert.ok(updated.includes(generated));
+  assert.ok(updated.includes(END));
+});
+
+test("features inventory generator fails closed when markers are missing", () => {
+  assert.throws(
+    () => updateFeaturesContent("# FEATURES\n\nNo markers here.\n"),
+    /FEATURES\.md is missing generated inventory markers/,
+  );
+});