db-context-postgres

name	db-context-postgres
description	Validate that a generic Postgres database (GCP Cloud SQL, GKE Autopilot, self-hosted, etc.) is reachable via psql or pg_dump, introspect a user-scoped subset of the schema (extensions, tables, columns, indexes, foreign keys, and optionally RLS policies and functions), 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 a non-Supabase Postgres database (Cloud SQL, GKE Autopilot Postgres, self-hosted Postgres, RDS, etc.), 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 a database, when the target is Supabase (use db-context-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 a generic Postgres deployment (GCP Cloud SQL, GKE Autopilot Postgres, self-hosted, AWS RDS, etc.) accessed via psql or pg_dump.

Goal: Validate that connection params resolve to a reachable Postgres instance, introspect a user-scoped subset of the schema (extensions, tables, columns, indexes, foreign keys, and optionally RLS policies and functions), 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 Postgres 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 (mode definitions only; the tool mapping table is lazy-loaded in wos/editor-mode-mappings.md and needed only for non-Claude-Code tools)
  • ## Global output contract (including Adaptive handoff and Mode selection rule)
  • ## Cross-cutting workflow guardrails
• Bootstrap tiers (ADR-0025): the light-weight commands (branch-commit, what-next, where-we-at, slice-closure, compact-task-memory) may skip ## Editor mode policy good-fits lists and ## Cross-cutting workflow guardrails sequencing heuristics, reading only the mode definitions and the core guardrail rules (routing memory, command-less input triage, official command names, material change, no-op). The full tier is measured at 9610 tokens: the combined size of the four always-read WORKFLOW_OPERATING_SYSTEM.md sections listed above. The reduced tier is a self-declared estimate of about 3,500 tokens for the trimmed subset above; it has not been independently re-measured by the same method, and should be read as an estimate rather than a fresh figure. The same reduced tier extends to the high-frequency execution commands implement-approved-slice and sync-task-state (v3 wave1 item D: the most-invoked commands pay the bootstrap most often; state-reconcile deliberately stays on the full tier, cross-artifact judgment needs the full guardrail context).
• Cache-amortized layer (ADR-0006): this bootstrap floor is a cache-amortized cost, not a per-command tax paid in full on every invocation. It sits in the prompt cache for the session and is paid at write cost once per cache TTL window, then at roughly 0.1x on cached reads inside that window. Account for it separately from any per-skill Load budget (the generated .claude/skills/<name>/SKILL.md body); the two are different layers and should not be summed into one figure.
• Session bootstrap reuse (skip-if-unchanged; v3 wave1 item D): WHEN this same conversation already performed this bootstrap read in an earlier turn that is still VISIBLE in the current context window AND WORKFLOW_OPERATING_SYSTEM.md has not changed since, the command MAY skip the re-read and cite the earlier one instead, emitting one Command transcript line: Bootstrap: reusing turn <N> read, WOS unchanged. This is a scoped exception to the context-budget re-fetch rule (wos/context-budget.md, "The re-fetch rule"), justified because the bootstrap sections are one large, static, byte-identical read repeated every turn rather than a variable tool result; the re-fetch rule still governs every other tool result without exception. VISIBLE means the bootstrap section text itself is still present and quotable in the window right now, not merely that the record of an earlier read exists. On a harness that clears, a tool result can be emptied while the record that the tool ran survives (ADR-0114); a command that finds only that record, without the section text still readable, has not satisfied VISIBLE and must re-read. Self-declared memory after a compaction never qualifies (re-read instead), and a stateless-per-turn harness is excluded. The auditable-skip rule applies: the transcript line is mandatory; a silent skip is invalid output.
• Read additional sections only when relevant to this command's role.
• Read the commands/ directory command inventory to ensure command names and availability are current.
• Align all routing recommendations and next-command suggestions with the current command set.
• Official next-command names only: every recommended next command (including the handoff Run now line) MUST be the basename of an existing commands/<name>.md file in this workflow repository. Never invent names.

Required inputs:

• active task path (or enough context to resolve projects/<client>__<project>/active/YYYY-MM-DD_<task-slug>/)
• connection params, provided via one of:
  • environment variables PGHOST, PGPORT, PGUSER, PGDATABASE, PGPASSWORD (or PGSSLMODE)
  • a DATABASE_URL (postgres://user:pass@host:port/dbname?sslmode=...)
  • a ~/.pgpass entry plus host/db identifiers
• 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)
• depth flag (one of):
  • tables-only: tables, columns with types, primary keys, not-null flags, indexes, foreign keys
  • tables+rls (default): tables-only plus row-level security policies for each in-scope table when RLS is in use
  • full: tables+rls plus relevant functions, triggers, extensions, and server version metadata
• optional: refresh flag (refresh to regenerate; 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 via psql (e.g. \dt, \d+, queries against information_schema / pg_catalog) or pg_dump --schema-only --no-owner --no-privileges. Never run INSERT / UPDATE / DELETE / DROP / ALTER / TRUNCATE / GRANT / REVOKE for any reason; redirect the user to the appropriate implementation command and stop.
• Do not invent tables, columns, types, indexes, foreign keys, policies, or functions. Every recorded field must come from the live introspection output or from explicit user-supplied scope.
• Always record Last refreshed: as today's date in YYYY-MM-DD format, the resolved host/database identifier, and the server version (SELECT version()). Stale snapshots without these fields are invalid.
• Never dump the entire database. If the target schema has more than 25 tables and the user provided 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. Handwritten notes belong in DECISIONS.md or TASK_STATE.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 psql output] when the introspection 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).
• Never log passwords or full DATABASE_URL values in the snapshot or transcript; record only host + database name + user (never the password component).
• Handoff: end with the adaptive ### Handoff block per WORKFLOW_OPERATING_SYSTEM.md ## Global output contract. 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: postgres
- Deployment: <cloud-sql | gke-autopilot | self-hosted | rds | other>
- Host/database: <host>/<dbname> (user: <user>)
- Server version: <output of SELECT version()>
- Last refreshed: YYYY-MM-DD
- Depth: tables-only | tables+rls | full
- Scope: <comma-separated list of schema.table or schema.* entries actually introspected>

## Extensions (only when depth = full)
- <extension_name> <version>

## 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>) [ON DELETE <action>] [ON UPDATE <action>]
- Indexes (non-PK, non-unique-constraint):
  - <index_name> ON (<columns>) [UNIQUE] [WHERE <predicate>]
- RLS enabled: yes | no | n/a
- RLS policies (only when depth >= tables+rls and RLS enabled):
  - <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 | c | ...>
- Security: <DEFINER | INVOKER>
- One-line summary: <verbatim COMMENT ON FUNCTION if present, else "[no COMMENT 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 connectivity precondition check (psql -c "SELECT 1" or equivalent succeeded / failed, plus resolved host/db/user; never the password).
3. Resolved scope (tables/schemas) and depth flag.
4. 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").
5. Exact content for DB_CONTEXT.md using the canonical snapshot format.
6. Exact patch to SOURCE_OF_TRUTH.md adding the ## DB context cross-link, or SKIP if the link is already present.
7. Recommended next command (must exist in commands/*.md; verify against directory listing before output).
8. Recommended editor mode for that next command.
9. 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 connectivity 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 (missing env var, unreachable host, auth failure, etc.).
• The proposed DB_CONTEXT.md includes Provider, Deployment, Host/database, Server version, 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, index, foreign key, policy, extension, and function entry is grounded in the live psql / pg_dump output; no field is fabricated. Ambiguous fields are marked [unclear from psql output].
• No destructive SQL was issued. Only read-only introspection was used.
• No credentials are leaked: passwords and full DATABASE_URL values never appear in the snapshot or transcript.
• 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 Postgres schema, point-in-time auditability, narrow scope (no full-DB dumps), credential hygiene, and minimal disruption to whatever task-scoped work was in progress before this capture.