db-context-supabase

name	db-context-supabase
description	Validate that a Supabase MCP server is reachable, introspect a user-scoped subset of the database (tables, columns, types, RLS policies, optionally functions and recent migrations), and persist the result as DB_CONTEXT.md inside the active task folder; adds a single ## DB context cross-link in SOURCE_OF_TRUTH.md. Read-only introspection only; never destructive SQL. Opt-in, not part of default task init. Use when the active task touches Supabase data/schema/RLS, when planning or implementation needs verified schema rather than assumed schema, or when an existing DB_CONTEXT.md is stale. Do not use without an active task folder (run task-init first), when the task does not touch Supabase, when the database is not Supabase, or when the user wants to record a schema decision (use decision-interview).
metadata	{"category":"database-context","primary-cursor-mode":"Ask","multi-repo-aware":false,"context-layers-consumed":["memory","retrieved"],"context-layers-produced":["memory"],"tools":["Read","Write","Edit","Bash","Glob","Grep"],"x-wos-profiles":["full"],"provenance":"first-party","suggested-model":"claude-sonnet-4-6"}

Act as a senior/staff engineering database context capture for the active task, scoped to Supabase.

Goal: Validate that a Supabase MCP server is configured and reachable, introspect a user-scoped subset of the database (tables, columns, types, RLS policies, and optionally functions/migrations), and persist the result as DB_CONTEXT.md inside the active task folder so the task has a grounded, point-in-time schema reference for planning, implementation, and review.

This command is opt-in. It is not part of the default task initialization flow; run it after task-init only when the task actually touches Supabase data, schema, or RLS.

Mandatory context bootstrap (before any output):

• Read these sections in WORKFLOW_OPERATING_SYSTEM.md first:
  • ## LLM execution contract
  • ## Editor mode policy
  • ## Global output contract (including Adaptive handoff and Mode selection rule)
  • ## Cross-cutting workflow guardrails
  • ## Evidence priority
• Read additional sections only when needed:
  • naming/path setup: ## Naming conventions, ## Repository structure
  • artifact requirements: ## Task files, ## TASK_STATE policy
• Read the active task's TASK_STATE.md to confirm there is an active task to attach the DB context to and to align the requested table/schema scope with the task objective.
• Read the active task's SOURCE_OF_TRUTH.md to detect any prior ## DB context link before proposing a new one.
• Read the commands/ directory command inventory to ensure routing recommendations are current.

Required inputs:

• active task path (or enough context to resolve projects/<client>__<project>/active/YYYY-MM-DD_<task-slug>/)
• scope of introspection, supplied by the user as one or more of:
  • list of table names (qualified schema.table or unqualified for the default public schema)
  • list of schemas to include in full (use sparingly; large schemas should be narrowed to specific tables)
• depth flag (one of):
  • tables-only: tables and columns with types, primary keys, and not-null flags
  • tables+rls (default): tables-only plus row-level security policies for each in-scope table
  • full: tables+rls plus relevant functions, triggers, and the most recent migration filenames touching in-scope tables
• optional: Supabase project ref (if the MCP server is configured for multiple projects); when omitted, use the project the MCP server is currently bound to and record which one was used
• optional: refresh flag (refresh to regenerate an existing DB_CONTEXT.md; default is to fail with NO_OP_TRACE if a non-stale DB_CONTEXT.md already exists for the same scope)

Project repository files to read:

• projects/__/active/YYYY-MM-DD_/TASK_STATE.md
• projects/__/active/YYYY-MM-DD_/SOURCE_OF_TRUTH.md
• projects/__/active/YYYY-MM-DD_/DB_CONTEXT.md (only if it already exists, for refresh comparison)

Project repository files to update:

• projects/__/active/YYYY-MM-DD_/DB_CONTEXT.md (create or fully regenerate; never partial-merge)
• projects/__/active/YYYY-MM-DD_/SOURCE_OF_TRUTH.md (append-only: add a single ## DB context section pointing to ./DB_CONTEXT.md if not already present)

Operating rules:

• Do not implement production code, migrations, or destructive SQL.
• Only issue read-only introspection queries through the MCP server. Never run INSERT / UPDATE / DELETE / DROP / ALTER / TRUNCATE / GRANT / REVOKE for any reason; if the user requests one, redirect them to the appropriate implementation command and stop.
• Do not invent tables, columns, types, policies, functions, or migrations. Every recorded field must come from the MCP server's response or from explicit user-supplied scope.
• Always record Last refreshed: as today's date in YYYY-MM-DD format and the resolved Supabase project identifier. Stale snapshots without these fields are invalid.
• Never dump the entire database. If the user provides a schema with more than 25 tables and no narrowing list, ask one targeted question to narrow scope before introspecting.
• Re-run policy: regeneration replaces DB_CONTEXT.md in full. Do not partial-merge. If the user has handwritten notes that should survive refresh, those belong in DECISIONS.md or TASK_STATE.md, not in DB_CONTEXT.md. State this explicitly when proposing a refresh that overwrites an existing file.
• Cross-link policy: SOURCE_OF_TRUTH.md gets at most one ## DB context section with a single relative pointer to ./DB_CONTEXT.md. Do not duplicate schema content into SOURCE_OF_TRUTH.md.
• Do not modify other task-scoped artifacts (TASK_STATE.md, DECISIONS.md, IMPLEMENTATION_PLAN.md, IMPACT_ANALYSIS.md, INVARIANTS_AND_NON_GOALS.md, TEST_STRATEGY.md, PR_PACKAGE.md, slice files).
• Treat task-memory write policy per WORKFLOW_OPERATING_SYSTEM.md: PROPOSED in Ask/Plan mode, APPLIED only in Agent mode.
• Mark fields as [unclear from MCP response] when the introspection tool returned ambiguous or partial data; never fill gaps with guesses.
• Output is intentionally bounded. Do not produce schema analysis, ER diagrams, or design recommendations beyond the snapshot itself; routing those follow-ups belongs in subsequent commands (impact-analysis, decision-interview, implementation-plan).
• Handoff: end with the adaptive ### Handoff block per WORKFLOW_OPERATING_SYSTEM.md ## Global output contract (Mode A compact or Mode B full). Default Run now: read TASK_STATE.md Last completed step; if it was task-init, default to impact-analysis; if uncertain, default to what-next.

Snapshot format (canonical):

# DB_CONTEXT

## Snapshot metadata
- Provider: supabase
- Project ref: <resolved-project-ref-or-alias>
- Last refreshed: YYYY-MM-DD
- Depth: tables-only | tables+rls | full
- Scope: <comma-separated list of schema.table or schema.* entries actually introspected>

## Tables

### <schema>.<table>
- Columns:
  - <column_name> <type> [PK] [NOT NULL] [DEFAULT <expr>]
- Primary key: <column(s)>
- Foreign keys:
  - <column> -> <ref_schema>.<ref_table>(<ref_column>)
- Indexes (non-PK, non-unique-constraint):
  - <index_name> ON (<columns>)
- RLS enabled: yes | no
- RLS policies (only when depth >= tables+rls):
  - <policy_name> [<command: SELECT/INSERT/UPDATE/DELETE/ALL>] FOR <role>: <USING expression> / <WITH CHECK expression>

## Functions (only when depth = full)
### <schema>.<function_name>(<args>)
- Returns: <return_type>
- Language: <plpgsql | sql | ...>
- Security: <DEFINER | INVOKER>
- One-line summary: <verbatim COMMENT ON FUNCTION if present, else "[no COMMENT in source]">

## Recent migrations touching in-scope tables (only when depth = full)
- <migration_filename_or_id>: <one-line description from migration metadata, or "[no description in source]">

Sections that have no content for the chosen depth must be omitted entirely rather than left empty.

Required output:

1. Resolved active task path.
2. Result of the MCP precondition check (configured / reachable / introspection tools available, or the actionable failure line).
3. Resolved Supabase project ref/alias used for introspection.
4. Resolved scope (tables/schemas) and depth flag.
5. Whether this is a create or a refresh of DB_CONTEXT.md, and (on refresh) a one-line drift summary versus the prior snapshot (e.g., "3 new columns, 1 dropped table, RLS toggled on public.orders").
6. Exact content for DB_CONTEXT.md using the canonical snapshot format.
7. Exact patch to SOURCE_OF_TRUTH.md adding the ## DB context cross-link, or SKIP if the link is already present.
8. Recommended next command (must exist in commands/*.md; verify against directory listing before output).
9. Recommended editor mode for that next command.
10. Why that is the correct next step.

Claim grounding (active epistemic humility)

Claim grounding (active epistemic humility). This block governs what you may assert and how you record it. It is keyed to the substrate section you are writing, not to which command is running, and it is INERT on any output that writes none of the claim-bearing sections below. Full contract and rationale: wos/active-epistemic-humility.md.

1. When this applies. This block fires ONLY while you are writing a claim-bearing substrate section: TASK_STATE.md ## Current known facts, ## Risks to watch, ## Observations, ## Active files in scope, ## Canonical decisions; DECISIONS.md ## Locked decisions; IMPLEMENTATION_PLAN.md ## Current gaps, ## Risks and mitigations; IMPACT_ANALYSIS.md; EXTERNAL_RESEARCH.md; REFERENCES.md; or any section whose content is a statement a later command or a human decision will act on. WHEN your output writes none of these, this block imposes nothing: skip it and proceed. This is the D-13 inert clause; a fully-grounded or claim-free output pays nothing.

2. The unit is the load-bearing claim. A load-bearing claim is one a downstream command or a human decision consumes. A passing aside is not load-bearing; a statement someone will act on is. Apply the rest of this block per load-bearing claim, not per sentence.

3. Ground it or abstain. Before you assert a load-bearing claim, trace it to the enumerable grounded set: a captured REFERENCES.md entry, a file read in this session, command output actually seen, or a passing deterministic gate. A claim supported only by model memory is OUTSIDE the grounded set, including when you are right, because that support is not observable. WHEN a load-bearing claim falls outside the set, do NOT assert it: either investigate until it is grounded, or abstain per rule 6.

4. Status records provenance, never confidence. WHERE you attach an epistemic status to a claim, the status names WHERE THE CLAIM CAME FROM: a REFERENCES.md entry title, a file path plus line, or the gate output it came from. It SHALL NOT express a degree of certainty. Do NOT add a confidence field, a numeric threshold, or a self-assessment prompt anywhere; a self-reported confidence signal is not a usable control signal (wos/active-epistemic-humility.md Part 1.3). A status whose referent slot is empty is read as UNKNOWN, not as a weak yes.

5. Persisted claims carry the status; chat-only claims carry it when they route. Every load-bearing claim you write into a task-memory artifact carries its provenance referent, and that referent travels with the claim so a later command reads it too; do not drop it at the write boundary. A load-bearing claim that appears only in a chat-turn output carries a status only when it crosses the grounding boundary and triggers a route (an abstention, an escalation).

6. Abstain as a routed continuation, never a bare refusal. WHEN you abstain, name the specific investigation that would settle the question AND route to the command that runs it (capture-references, code-locate, incident-triage, or the fitting one). A withholding that stalls the work is invalid output. Abstention is distinct from NO_OP: NO_OP means there is no work to do; abstention means there is work and the grounding to do it is missing.

7. An unfired gate is not evidence. The absence of a fired check does not mean grounding existed. Do not read silence here as a pass.

Standard output layout (required)

Produce the command output using this structure (English only):

Artifact changes

Follow ## Global output contract in WORKFLOW_OPERATING_SYSTEM.md for APPLIED / PROPOSED / SKIP rules.

Command transcript

Brief audit trail (max 4 lines; max 3 in no-op runs with NO_OP_TRACE).

Handoff

Use the adaptive ending format from WORKFLOW_OPERATING_SYSTEM.md ## Global output contract (Mode A compact or Mode B full per session state).

Definition of done (command output)

• The MCP precondition check is performed first and its result is reported; if it failed, no DB_CONTEXT.md content is proposed and the run ends with NO_OP_TRACE plus the actionable configuration line.
• The proposed DB_CONTEXT.md includes Provider, Project ref, Last refreshed, Depth, and Scope metadata, and at least one populated ## Tables entry (or an explicit NO_OP_TRACE if the requested scope returned no tables).
• Every column type, policy, function, and migration entry is grounded in the MCP server's response; no field is fabricated. Ambiguous fields are marked [unclear from MCP response].
• No destructive SQL was issued. Only read-only introspection was used.
• No task-scoped artifact other than DB_CONTEXT.md and (at most) a single ## DB context cross-link in SOURCE_OF_TRUTH.md is modified.
• On refresh, the prior DB_CONTEXT.md is fully replaced (no partial merge), and the drift summary in the required output makes the change auditable.
• ### Artifact changes marks the patches as PROPOSED in Ask mode or APPLIED only when the user explicitly authorized Agent persistence.
• The basename in the Run now: line corresponds to a real file in commands/<name>.md.
• Output ends with a complete ### Handoff block per the adaptive format in WORKFLOW_OPERATING_SYSTEM.md ## Global output contract.
• Before declaring this output done, confirm it satisfies the shared Definition of done (command outputs) and Gate conditions in WORKFLOW_OPERATING_SYSTEM.md.

Quality bar: Optimize for fidelity to the live Supabase schema, point-in-time auditability, narrow scope (no full-DB dumps), and minimal disruption to whatever task-scoped work was in progress before this capture.