Vision Driven Design (VDD) MCP Server

Measured conclusion: Alive, not deep-tested. L2 outcome: not_attempted.

Spec-driven development MCP server: 8 phases, bi-directional traceability, 7 quality gates.

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Copy this into your MCP client config:

{
  "mcpServers": {
    "Vision Driven Design (VDD) MCP Server": {
      "url": "https://vdd.simonmak.com/api/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (15)

• vdd_init read-only

  VDD Phase 0: Generate constitution.md at the project root — the immutable tech stack, conventions, security constraints, naming rules, and banned patterns that every later phase obeys. Overwrites any existing constitution.md. Run this first, before vdd_vision; to change a constitution that already exists, use vdd_amend instead of re-running this. projectRoot sets the directory constitution.md is written to and that later phases resolve every vdd/ artifact against (default "."). Parameter relationships: projectRoot defaults to "." and must be the same root every later phase resolves against.

  Parameters:

  • projectRoot — string — Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

• vdd_vision read-only

  VDD Phase 1: Expand a freeform vision statement into vdd/vision.md — Impact Model (Goal, Actors, Impacts), Stakeholder Map, Success Metrics (leading + lagging), Constraints & Boundaries, and Target Domains. Overwrites any existing vdd/vision.md. Requires statement (freeform 1-3 paragraph intent, not a title) and a prior vdd_init. Run once, after vdd_init and before vdd_strategize; to revise a vision once downstream artifacts exist, use vdd_amend so the change cascades instead of re-running this. Parameter relationships: statement must be freeform prose (1-3 paragraphs), not a title; projectRoot must match the root used by vdd_init.

  Parameters:

  • statement (required) — string — Freeform vision statement
  • projectRoot — string — Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

• vdd_strategize read-only

  VDD Phase 2: Produce research-backed strategy into vdd/strategy.md — strategic pillars, competitive analysis, and a risk register, resolved from the vision target-domain primers. Overwrites vdd/strategy.md. Requires vdd/vision.md; run after vdd_vision and before vdd_tactics. Two-pass: call once with availableTools to get the research-subagent dispatch specs, then re-call with researchFindings to synthesize strategy.md (a first call with neither returns only the dispatch specs). To change strategy after artifacts exist, use vdd_amend. Parameter relationships: availableTools and capabilities are aliases (pass one); researchFindings only has an effect on the second call.

  Parameters:

  • projectRoot — string — Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")
  • capabilities — array — Alias for availableTools
  • availableTools — array — MCP/tool names available to the host agent (e.g., ["brave-search","perplexity","context7","gh_grep","playwright","filesystem"])
  • researchFindings — string — Consolidated research subagent findings to synthesize into strategy.md (effect only on the second strategize call)

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

• vdd_tactics read-only

  VDD Phase 3: Audit the existing codebase into vdd/tactics.md — repo audit, technical-debt assessment, gap analysis, MoSCoW-prioritized action items (A-001, A-002, …), dependency map, and infrastructure requirements. Overwrites vdd/tactics.md. Requires vdd/strategy.md; run after vdd_strategize and before vdd_specify. Needs a filesystem-capable host to scan the repo, so check with vdd_detect_environment first if the host may lack one. Parameter relationships: projectRoot must match the root used by vdd_init, vdd_vision, and vdd_strategize; requires vdd/strategy.md to exist. On the hosted (stateless) endpoint the tool cannot scan the repo itself: pass artifactFiles ({"vdd/strategy.md": "..."}) plus codebaseAudit (the repo scan produced by the host agent) to receive the audit; without them it returns a delegation envelope.

  Parameters:

  • projectRoot — string — Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")
  • artifactFiles — object — Map of vdd/-relative artifact path → full file text, for the hosted (stateless) endpoint, which cannot read the caller filesystem; without it the tool returns a delegation envelope
  • codebaseAudit — string — Repo scan (directory tree, manifests, modules, debt) produced by the host agent, for tactics on the hosted (stateless) endpoint which cannot scan the repo itself

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

• vdd_specify read-only

  VDD Phase 4: Generate vdd/specs/<id>/spec.md for one tactical action item — user stories, Always/Ask/Never boundaries, Given/When/Then acceptance criteria (AC), MoSCoW priorities, non-functional requirements, and impact verification. Overwrites the spec file. Pass actionItemId (e.g. "A-001") or a freeform description to skip the V/S/T chain. Use for a NEW spec; to resolve leftover [NEEDS CLARIFICATION] markers in an existing spec use vdd_clarify instead. Parameter relationships: feature names the vdd/specs/<feature>/ directory and must match the feature passed to vdd_clarify, vdd_plan, and vdd_tasks; actionItemId is the A-### id from tactics.md and is optional when authoring from a freeform description.

  Parameters:

  • feature — string — Feature name: the vdd/specs/<feature>/ directory, kebab-case (e.g., "user-auth"); must reference a directory created earlier by vdd_specify
  • description — string — Freeform description input
  • projectRoot — string — Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")
  • actionItemId — string — Tactical action item ID, format A-### (e.g., "A-001"); must be an item id from vdd/tactics.md

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

• vdd_clarify read-only

  VDD Phase 4b: Clarify an existing spec — scans vdd/specs/<feature>/spec.md and returns the items to resolve: every [NEEDS CLARIFICATION] marker, [e.g.] placeholder, and happy-path acceptance criterion (AC) still needing an edge-case counterpart (AC-E*). Read-only; returns the list without editing the file (the host agent then applies the resolutions). Pass feature (spec directory name). Run after vdd_specify when a spec has unresolved markers; to author a brand-new spec use vdd_specify instead. Parameter relationships: feature must be the exact spec directory name created by vdd_specify. On the hosted (stateless) endpoint, pass artifactFiles ({"vdd/specs/<feature>/spec.md": "..."}) so the tool can scan the spec and return the real markers; without it the tool returns a delegation envelope.

  Parameters:

  • feature (required) — string — Feature name: the vdd/specs/<feature>/ directory, kebab-case (e.g., "user-auth"); must reference a directory created earlier by vdd_specify
  • projectRoot — string — Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")
  • artifactFiles — object — Map of vdd/-relative artifact path → full file text, for the hosted (stateless) endpoint, which cannot read the caller filesystem; without it the tool returns a delegation envelope

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

• vdd_plan read-only

  VDD Phase 5: Generate the technical blueprint under vdd/specs/<feature>/ — plan.md (component breakdown, AC coverage map, technology choices, verification toolchain), data-model.md (entities, indexes, migrations), and contracts/ (request/response/error schemas). Overwrites these files. Requires an existing spec for the feature; run after vdd_specify or vdd_clarify and before vdd_tasks — if no spec exists yet, run vdd_specify first. Parameter relationships: feature must match the value passed to vdd_specify and vdd_tasks.

  Parameters:

  • feature (required) — string — Feature name: the vdd/specs/<feature>/ directory, kebab-case (e.g., "user-auth"); must reference a directory created earlier by vdd_specify
  • projectRoot — string — Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

• vdd_tasks read-only

  VDD Phase 6: Break the plan into atomic test-first tasks in vdd/specs/<feature>/tasks.md — each references acceptance criteria (AC) and contracts, is sized S/M/L, and is marked [P] when parallelizable. Overwrites tasks.md. Requires plan.md; run after vdd_plan. To fetch the next uncompleted task from an existing tasks.md use vdd_get_next_task instead of re-running this. Parameter relationships: feature must match the value passed to vdd_plan.

  Parameters:

  • feature (required) — string — Feature name: the vdd/specs/<feature>/ directory, kebab-case (e.g., "user-auth"); must reference a directory created earlier by vdd_specify
  • projectRoot — string — Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

• vdd_get_next_task read-only

  VDD Phase 7a: Read vdd/specs/<feature>/tasks.md and return the next uncompleted task (or a completion marker when none remain). Read-only; never edits tasks.md. Pass feature (the exact spec directory name). Use before each implementation session to keep context isolated; to regenerate the whole list use vdd_tasks, and to execute the returned task use vdd_implement. Parameter relationships: feature must match the spec directory; the returned taskId (TASK-###) is the argument to vdd_implement. On the hosted (stateless) endpoint, pass artifactFiles ({"vdd/specs/<feature>/tasks.md": "..."}) so the tool returns the real next uncompleted task; without it the tool returns a delegation envelope.

  Parameters:

  • feature (required) — string — Feature name: the vdd/specs/<feature>/ directory, kebab-case (e.g., "user-auth"); must reference a directory created earlier by vdd_specify
  • projectRoot — string — Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")
  • artifactFiles — object — Map of vdd/-relative artifact path → full file text, for the hosted (stateless) endpoint, which cannot read the caller filesystem; without it the tool returns a delegation envelope

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

• vdd_implement read-only

  VDD Phase 7b: Prepare one task for implementation — loads constitution, spec, plan, and contracts and returns the implementation instruction plus the impact-chain commit-message format. Read-only; the tool writes nothing — the host agent performs the code edits, verification, and commit. Pass taskId (e.g. "TASK-003") from the task returned by vdd_get_next_task. Run one task at a time, after vdd_get_next_task; for read-only inspection of tasks use vdd_get_next_task instead. Parameter relationships: taskId comes from vdd_get_next_task (format TASK-###); projectRoot must match the root used by earlier phases. On the hosted (stateless) endpoint, pass artifactFiles (constitution.md, spec.md, plan.md, contracts/, tasks.md) so the tool can embed the real task text and its AC/contract links; without it the tool returns a delegation envelope.

  Parameters:

  • taskId (required) — string — Task ID to implement, format TASK-### (e.g., "TASK-003"); must be an id listed in the feature's tasks.md (see vdd_get_next_task)
  • projectRoot — string — Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")
  • artifactFiles — object — Map of vdd/-relative artifact path → full file text, for the hosted (stateless) endpoint, which cannot read the caller filesystem; without it the tool returns a delegation envelope

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

• vdd_validate read-only

  VDD Phase 8: Validate the full chain — bidirectional traceability matrix, drift detection, orphan detection, uncovered vision goals, impact metrics vs targets, and 28 S&T assumption checks across 7 gates. Writes vdd/impact-report.generated.md and never overwrites a hand-authored vdd/impact-report.md. Run after implementation is complete; for the traceability matrix or per-feature spec metrics use vdd_inspect. Parameter relationships: feature narrows the check to one spec; artifactFiles maps artifact path to content for serverless runs and is omitted when resolving against a local projectRoot. On the hosted (stateless) endpoint, pass artifactFiles (the vdd/ artifacts) so the tool can run drift/orphan/substance checks; without it the tool returns a delegation envelope.

  Parameters:

  • feature — string — Feature name: the vdd/specs/<feature>/ directory, kebab-case (e.g., "user-auth"); must reference a directory created earlier by vdd_specify
  • projectRoot — string — Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")
  • artifactFiles — object — Map of vdd/-relative artifact path → full file text, for the hosted (stateless) endpoint, which cannot read the caller filesystem; without it the tool returns a delegation envelope

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

• vdd_inspect read-only

  VDD Cross-phase: Read-only inspection of the current project in one call — scope selects the view. scope="project" (default) returns the bidirectional V→S→T→SP→PL→TK traceability matrix across all vdd/ artifacts; scope="feature" returns per-feature spec metrics (acceptance-criteria count, unresolved [NEEDS CLARIFICATION] markers, [e.g.] placeholder density, and whether plan.md/tasks.md exist). Never modifies files. Pass feature for the feature scope; for release-readiness validation with gates use vdd_validate, and to author a spec use vdd_specify. Output is a structured matrix/metrics object, not prose. Parameter relationships: scope="feature" requires feature, while scope="project" (the default) ignores it; projectRoot must match the root used by earlier phases. On the hosted (stateless) endpoint, pass artifactFiles (path→content for the vdd/ artifacts) so the tool computes the real matrix/metrics; without it the tool returns a delegation envelope.

  Parameters:

  • scope — string — Inspect scope: "project" (default) returns the traceability matrix; "feature" returns per-feature spec metrics (requires feature)
  • feature — string — Feature name: the vdd/specs/<feature>/ directory, kebab-case (e.g., "user-auth"); must reference a directory created earlier by vdd_specify
  • projectRoot — string — Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")
  • artifactFiles — object — Map of vdd/-relative artifact path → full file text, for the hosted (stateless) endpoint, which cannot read the caller filesystem; without it the tool returns a delegation envelope

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

• vdd_amend read-only

  VDD Cross-phase: Plan a requirement-change cascade through the whole chain — identifies the highest affected level and returns the ordered steps to update downward V→S→T→SP→PL→TK and re-run affected gates (G1–G7). Read-only; returns the cascade plan without editing artifacts (the host agent applies the edits and commits). Pass the change as description. Use when a requirement changes after artifacts already exist; to build a phase from scratch the first time, run that phase's own tool instead of vdd_amend. The plan is an ordered step list naming the affected gates, not rewritten artifacts. Parameter relationships: description is the requirement change to cascade through the artifact chain; projectRoot must match the root used by earlier phases.

  Parameters:

  • description (required) — string — Description of the requirement change
  • projectRoot — string — Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

• vdd_clone read-only

  Crawl and capture a target domain into a clone dataset + manifest — WordPress-aware schema inference, Payload collections, and a Next.js + Payload + Postgres scaffold manifest (vdd/clone-manifest.json). Pass the domain as description. Writes vdd/clone-dataset.json, vdd/clone-manifest.json, and vdd/clone.md, overwriting any existing versions in place. Open-world: makes network requests to the target site and reads its sitemap and same-origin links. Use for cloning an external site; it is not part of the VDD phase pipeline, so for the normal init→validate flow call those phase tools instead. Parameter relationships: description is the target domain and statement is the desired outcome (both optional); maxPages, timeoutMs, concurrency, crawl, and browser tune the crawl and refresh=true bypasses a cached dataset.

  Parameters:

  • crawl — boolean — Clone: run the crawl (default true). Local stdio server only; ignored by the hosted endpoint
  • browser — boolean — Clone: run browser/static capture (default true). Local stdio server only; ignored by the hosted endpoint
  • refresh — boolean — Clone: force re-crawl, ignore a fresh cached dataset. Local stdio server only; ignored by the hosted endpoint
  • maxPages — integer — Clone: max pages to crawl, 1-5000 (default 200). Local stdio server only; ignored by the hosted endpoint
  • statement — string — Freeform vision statement (required for vision)
  • timeoutMs — integer — Clone: per-request timeout in ms, 1000-60000 (default 10000). Local stdio server only; ignored by the hosted endpoint
  • concurrency — integer — Clone: concurrent crawl workers, 1-16 (default 8). Local stdio server only; ignored by the hosted endpoint
  • description — string — Freeform description input
  • projectRoot — string — Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

• vdd_detect_environment read-only

  VDD Environment Detection: Report which tools/MCPs each VDD phase requires vs treats as optional — across the 8-phase pipeline (init through validate) plus the cross-phase helpers (amend, clone, inspect, get-next-task) — and which of the host agent availableTools are present vs missing. Read-only; returns a capability report without modifying files. Run before vdd_strategize to plan research-subagent dispatch, or when a phase fails for lack of a tool; to inspect artifacts instead of capabilities use vdd_inspect. Returns a fixed-shape capability report; tool-name matching is normalized, so pass names as your host exposes them. Parameter relationships: availableTools and capabilities are aliases; omit both to get the per-phase requirements without a present/missing comparison.

  Parameters:

  • projectRoot — string — Project root: directory that constitution.md and the vdd/ folder are written to and resolved against. Relative paths resolve from the current working directory; keep the same value across every phase (default ".")
  • capabilities — array — Alias for availableTools
  • availableTools — array — MCP/tool names available to the host agent (e.g., ["brave-search","perplexity","context7","gh_grep","playwright","filesystem"])

  Hints: read-only yes · destructive not declared · idempotent yes · open-world no

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