Diagnose

Always lead with the full telemetry analysis. Do NOT ask the user how it tasted before presenting the analysis. The telemetry tells its own story — present it first. If the user hasn't volunteered taste feedback, ask at the END of the analysis so you can refine recommendations.

Fetch telemetry:

Use: analyze_shot(shot_id)

Fetch shot notes if available:

Use: manage_shot_notes(shot_id, action="get")

1b. IDENTIFY Shot Style

Before analyzing, identify the shot style so you compare against the right expectations. Use three tiers of detection (try in order, use first that succeeds):

Tier 1 — Fetch profile definition (preferred):

If analyze_shot returns a profile_id, fetch the full profile:

Use: manage_profile(action="get", profile_id=<profile_id>)

Classify by phase structure:

• Has a phase with pump off ("target": "power" and "pressure": 0) → Bloom (light roast bloom or natural process bloom)
• Flow-targeted extraction with flow >= 3.5 ml/s → Turbo
• Brew phase with pressure declining >= 4 bar over >= 15s → Lever Decline
• Extraction pressure <= 7 bar + high volumetric target (>= dose × 3.5) → Allongé
• Extraction pressure < 9 bar, no bloom, no decline → Dark/Gentle
• Default → Classic 9-Bar

Tier 2 — Profile name keywords (fallback):

If profile definition is unavailable, match profile_name from analyze_shot:

• Contains "turbo" → Turbo
• Contains "bloom", "natural bloom" → Bloom
• Contains "allongé", "allonge", "lungo" → Allongé
• Contains "lever", "decline" → Lever Decline
• Contains "gentle", "dark", "milk" → Dark/Gentle
• Otherwise → Classic 9-Bar

Tier 3 — Telemetry fingerprint (last resort):

If neither profile definition nor meaningful profile name is available, classify from the shot telemetry itself. See references/TELEMETRY_PATTERNS.md (Style Detection Fingerprints section) for the fingerprint table.

2. ANALYZE Telemetry

First, determine the final weight — NEVER ask the user. The BT scale frequently produces artifacts: spikes, drops to 0g, or null readings near end-of-shot. You MUST estimate the dose out yourself using the telemetry. Do not ask the user what the cup weighs — figure it out from the data.

Weight estimation priority (use first available):

1. Last stable weight sample — scan weight samples backward from end-of-shot, skip any that drop to 0g or spike >2× the inter-sample trend. The last reading consistent with the trend is your true weight.
2. Flow meter total minus puck absorption — if weight data is too sparse or entirely null, use total_volume_ml × 0.82 (≈18% absorbed by puck) as your dose-out estimate. This is approximate but sufficient for diagnosis.
3. Interpolate from mid-shot weight + flow — if you have a reliable weight reading mid-shot and flow data for the remainder, project forward.

State your estimated dose out and how you derived it, then move on. A ±2g estimate is fine for diagnostic purposes — don't let imperfect weight data stall the analysis.

Then, filter other BT scale artifacts. Beyond weight, volume readings can also spike. If any late-shot sample differs from the preceding trend by >2× the average inter-sample change, discard it. See references/TELEMETRY_PATTERNS.md (Bluetooth Scale Artifacts section) for full detection rules.

Load style-specific expectations from knowledge/PRESSURE_GUIDE.md (Pressure by Shot Style section) and knowledge/PROFILE_LIBRARY.md (Quick Reference table). Compare the shot's telemetry against those style-specific ranges — not generic 9-bar ranges.

Universal thresholds (style-independent):

Style-specific thresholds — loaded from knowledge files per identified style:

Flag an anomaly only when a metric falls outside the identified style's expected range. For example, 6 bar and 17s is anomalous for Classic 9-Bar but perfectly normal for Turbo.

2b. COMPARE Intended vs Actual (when profile definition available)

If you fetched the profile definition in Step 1b (Tier 1), compare each phase's intended parameters against the actual telemetry:

This phase-by-phase comparison is the most precise diagnostic — it shows exactly where in the shot things diverged from intent. Include the comparison in your diagnosis when available.

Compliance metrics (quantitative grind-direction signal): When analyze_shot returns a compliance_metrics block, use it alongside the manual table above to sharpen your diagnosis. The metrics operate on brew-phase samples only (filtered at ≥50% of peak pressure), so bloom and ramp data are excluded automatically.

brew_phase_sample_count is available for confidence context: a count of 3–4 means the metrics are based on very few samples and should be weighted lightly.

3. CORRELATE Taste with Telemetry

Cross-reference the user's taste feedback with telemetry patterns.

See: references/TELEMETRY_PATTERNS.md for detailed correlation matrix.

3b. AUTO-TRIGGER Feedback (4-5 Star Shots)

If the user provides a rating of 4 or 5 stars (explicitly like "5/5" or "4 stars", or implied like "this is great", "really dialed in", "best shot yet") and provides taste descriptors, automatically run the /feedback skill after completing the diagnosis. Do NOT ask — just invoke it with the shot ID, rating, and taste notes gathered during diagnosis. The user expects the full feedback loop (grind map update, tasting notes, device sync) to happen seamlessly.

For shots rated 1-3 or with no clear rating, do NOT auto-trigger — focus on diagnostic recommendations and let the user decide.

4. RECOMMEND Actions

Provide specific, prioritized recommendations:

1. Primary adjustment (most likely to fix the issue)
2. Secondary adjustment (if primary doesn't work)
3. Profile consideration (if extraction mechanics need changing)

Always explain WHY each recommendation addresses the diagnosed issue.

Profile modifications: If the user approves a profile change, follow the repo-first rule: update the JSON file in coffees/{coffee}/ first, then upload to device via manage_profile. Never modify the device profile without saving to the repo file. Check user-setup.md → Active Coffee for the coffee directory path.

Decision trees: For taste-based diagnostic trees (SOUR, BITTER, FLAT/MUTED, INCONSISTENT), see references/DIAGNOSTIC_TREES.md.

Telemetry correlation, equipment differentiation, multi-shot comparison: See references/TELEMETRY_PATTERNS.md.

4b. SELF-CHECK via Multi-Agent Review

After forming all recommendations (Step 4) but before presenting to the user, run a two-stage reasoning check. Full protocol (claims format, prompt templates, confidence calibration) in references/SELF_CHECK.md.

Step 1 — Extract claims block: From your full draft (telemetry summary + diagnosis + recommendations), extract a <claims> block listing: SHOT_STYLE, one GRIND_DIRECTION line per grind signal (including taste-based signals — especially if they conflict with telemetry signals), PRESSURE_NARRATIVE, TASTE_SIGNAL, PRIMARY_DIAGNOSIS, PRIMARY_RECOMMENDATION. Include every grind direction signal in the draft, even conflicting ones.

Step 2 — Spawn Sonnet critic: Spawn a critic via the Task tool (subagent_type: general-purpose) using the Critic Prompt Template from references/SELF_CHECK.md, with your draft and claims block substituted in.

Step 3 — Evaluate result:

• STATUS: CLEAR → present draft to user as-is (omit claims block from output)
• STATUS: OBJECTIONS → proceed to Step 4

Step 4 — Spawn Opus arbiter (only when objections found): Spawn via Task tool (subagent_type: general-purpose, model: opus) using the Arbiter Prompt Template from references/SELF_CHECK.md. Present the arbiter's corrected output to the user. Add a confidence note only if confidence is Low or Medium.

Integration with Other Knowledge

Always loaded (already referenced in Steps 1-4 — no additional loading needed):

• knowledge/PRESSURE_GUIDE.md — style-specific pressure expectations (Step 2)
• knowledge/PROFILE_LIBRARY.md — expected time, ratio, flow by style (Step 2)
• knowledge/ESPRESSO_BREWING_BASICS.md — adjustment strategies (Step 4)

Load ONLY when trigger applies:

Stop rule: Standard diagnosis uses only the always-loaded files + skill references (TELEMETRY_PATTERNS.md, DIAGNOSTIC_TREES.md). Loading knowledge/reference/ files during routine diagnosis is over-researching.

Response Format

Structure your diagnostic response as:

## Shot Analysis: [Shot ID]

### Identified Style: [Style Name]
(detected via [Tier 1: profile definition / Tier 2: profile name / Tier 3: telemetry fingerprint])

### Telemetry Summary
- **Pressure:** [peak] bar (style expects: X-Y bar)
- **Flow:** [avg] ml/s, first drip at [X]s (style expects: A-B ml/s)
- **Temperature:** [avg]°C (target: X°C, variance: ±X°C)
- **Timing:** [total]s total (style expects: E-Fs)

### Phase Comparison (if profile definition available)
[Intended vs actual for each phase — pressure, flow, timing]

### Diagnosis
[Correlation between telemetry and reported taste, interpreted through style-specific expectations]

### Recommendations
1. **[Primary fix]** — [specific action with reasoning]
2. **[Secondary fix]** — [backup if primary doesn't work]
3. **[Profile consideration]** — [if applicable]

### What to Watch For
[What user should observe on next shot to confirm diagnosis]

Example Diagnoses

Example 1: Classic 9-Bar — Sour and Watery

User says: "That shot was really sour and watery."

Style identified: Classic 9-Bar (expects 8-10 bar, 25-32s, 1.5-2.5 ml/s)

Telemetry: Pressure 7.2 bar, first drip 2.8s, flow 3.4 ml/s avg, 22s total

Diagnosis:

Your pressure never reached the Classic 9-Bar range (7.2 bar vs 8-10 bar expected) and the first drip came extremely fast (2.8s). Combined with high flow rate (3.4 ml/s vs 1.5-2.5 expected), the puck offered very little resistance. Classic under-extraction.

Primary fix: Grind 2-3 steps finer. We need to build more resistance.

Watch for: Time to first drip should increase to 5-7 seconds, and pressure should reach 8-9 bar.

Example 2: Bloom Profile — NOT a Problem

User says: "Shot took 38 seconds and pressure was only 7.5 bar — is that okay?"

Style identified: Natural Process Bloom (expects 7-9 bar, 30-38s, bloom pause is normal)

Diagnosis:

For a bloom profile, 38s total and 7.5 bar extraction pressure are right in the expected range. The bloom pause adds 10-15 seconds that a classic shot wouldn't have, and 7.5 bar is intentional for this natural-process coffee. These are features, not bugs. How did it taste?