Profiling Slow API Endpoints
PostHog/posthog-foss
Profiles slow PostHog API endpoints when the main cost is in Postgres or Python.
Analyze Django Silk profiling data to debug slow requests, detect N+1 queries, and optimize database performance.
Install Silk Debug
$ npx skills add letsrevel/revel-backend --skill silk-debug -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install letsrevel/revel-backend silk-debug --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/letsrevel/revel-backend.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.claude/skills/silk-debug .claude/skills/silk-debug && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "silk-debug" agent skill from https://github.com/letsrevel/revel-backend/tree/main/.claude/skills/silk-debug into .claude/skills/silk-debug/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "silk-debug", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/letsrevel/revel-backend/tree/main/.claude/skills/silk-debugType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add letsrevel/revel-backend --skill silk-debug -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install letsrevel/revel-backend silk-debug --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/letsrevel/revel-backend.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.claude/skills/silk-debug .agents/skills/silk-debug && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "silk-debug" agent skill from https://github.com/letsrevel/revel-backend/tree/main/.claude/skills/silk-debug into .agents/skills/silk-debug/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "silk-debug", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add letsrevel/revel-backend --skill silk-debug -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install letsrevel/revel-backend silk-debug --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/letsrevel/revel-backend.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.claude/skills/silk-debug .cursor/skills/silk-debug && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "silk-debug" agent skill from https://github.com/letsrevel/revel-backend/tree/main/.claude/skills/silk-debug into .cursor/skills/silk-debug/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "silk-debug", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/letsrevel/revel-backend.git --path .claude/skills/silk-debug--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add letsrevel/revel-backend --skill silk-debug -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install letsrevel/revel-backend silk-debug --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/letsrevel/revel-backend.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.claude/skills/silk-debug .gemini/skills/silk-debug && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "silk-debug" agent skill from https://github.com/letsrevel/revel-backend/tree/main/.claude/skills/silk-debug into .gemini/skills/silk-debug/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "silk-debug", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install letsrevel/revel-backend silk-debugInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add letsrevel/revel-backend --skill silk-debug -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/letsrevel/revel-backend.git skills-src && mkdir -p .github/skills && cp -r skills-src/.claude/skills/silk-debug .github/skills/silk-debug && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "silk-debug" agent skill from https://github.com/letsrevel/revel-backend/tree/main/.claude/skills/silk-debug into .github/skills/silk-debug/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "silk-debug", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add letsrevel/revel-backend --skill silk-debug -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install letsrevel/revel-backend silk-debug --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/letsrevel/revel-backend.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.claude/skills/silk-debug .opencode/skills/silk-debug && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "silk-debug" agent skill from https://github.com/letsrevel/revel-backend/tree/main/.claude/skills/silk-debug into .opencode/skills/silk-debug/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "silk-debug", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
silk-debug- GitHub stars
- 109
- Token cost
- ~1.2k tokens
- SKILL.md length
- 405 words
- Files
- 1
- Skills in repo
- 5
- Repo updated
- First seen
- Licence
- MIT
At a glance
Analyze Django Silk profiling data to debug slow requests, detect N+1 queries, and optimize database performance.
- Works in 3 steps: COUNT on complex DISTINCT: Pagination… → Missing indexes: Full table scans → Complex JOINs: Multiple related tables
- Analyzing request IDs
- SKILL.md covers Tool Location, Quick Reference, Interpreting Results and Common Optimization Patterns, plus 1 more section
- Calls python
What it does
Silk Debug is an agent skill from letsrevel/revel-backend. Analyze Django Silk profiling data to debug slow requests, detect N+1 queries, and optimize database performance. Use when analyzing request IDs, investigating slow endpoints, or optimizing query performance.
Its SKILL.md is about 1.2k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Backend & APIs, covering Query optimization and Backend development. It works with Django and Python. The repository describes itself as: Open-source event management, ticketing and membership platform for communities, clubs, independent venues and independent artists. The licence is MIT.
When your agent uses it
- Analyzing request IDs
- Investigating slow endpoints
- Optimizing query performance
Example prompts
- “/silk-debug”
Requirements
- Python 3
- Pre-approved tools (allowed-tools): Bash(python:*), Bash(.venv/bin/python:*), Read, Grep
Workflow steps
3 steps, taken from the first numbered list in SKILL.md.
- COUNT on complex DISTINCT: Pagination wrapping complex visibility subqueries
- Missing indexes: Full table scans
- Complex JOINs: Multiple related tables
What it can do on your machine
Read from SKILL.md and the folder at commit ae56c86. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves these tools, so the agent can use them without asking each time:
Bash(python:*)Bash(.venv/bin/python:*)ReadGrep
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
python
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Silk Debug loads about 1.2k tokens when it runs. Until then it costs about 55 tokens; SKILL.md has 405 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from letsrevel/revel-backend at commit ae56c86, republished under its MIT licence (© letsrevel). 405 words, ~1,242 tokens.
Download SKILL.mdSave it as
.claude/skills/silk-debug/SKILL.md (or your agent's skills folder).- name
- silk-debug
- description
- Analyze Django Silk profiling data to debug slow requests, detect N+1 queries, and optimize database performance. Use when analyzing request IDs, investigating slow endpoints, or optimizing query performance.
- allowed-tools
- Bash(python:*), Bash(.venv/bin/python:*), Read, Grep
Silk Debug Tool
A CLI tool for analyzing Django Silk profiling data to debug slow requests, detect N+1 queries, and optimize database performance.
Tool Location
.venv/bin/python scripts/silk_debug.pyQuick Reference
Analyze a Specific Request
When given a Silk request ID (UUID), use --full for comprehensive analysis:
.venv/bin/python scripts/silk_debug.py <request_id> --fullThis shows:
- Request info (path, method, status, time, query count)
- Duplicate/similar queries (N+1 detection)
- Slow queries (>5ms by default)
- Queries grouped by table
- Query execution timeline
- Python cProfile data (if enabled)
List and Filter Requests
# List recent requests
.venv/bin/python scripts/silk_debug.py --list
# Sort by different criteria
.venv/bin/python scripts/silk_debug.py --list --sort queries # Most queries
.venv/bin/python scripts/silk_debug.py --list --sort duration # Slowest total time
.venv/bin/python scripts/silk_debug.py --list --sort db_time # Most DB time
# Filter requests
.venv/bin/python scripts/silk_debug.py --list --path /api/events --min-queries 20
.venv/bin/python scripts/silk_debug.py --list --method POST --min-time 100Aggregate Analysis
# Overall statistics
.venv/bin/python scripts/silk_debug.py --stats
# Endpoint summary (grouped by path pattern, shows P95)
.venv/bin/python scripts/silk_debug.py --endpoints
# Find slow endpoints
.venv/bin/python scripts/silk_debug.py --slow-endpoints --slow-endpoint-threshold 100Interpreting Results
N+1 Query Detection
When you see duplicate queries like:
🔴 15x similar queries:
SELECT "events_ticket"."id" FROM "events_ticket" WHERE "events_ticket"."event_id" = '<UUID>'This indicates an N+1 problem. Fix with:
select_related()for ForeignKey fieldsprefetch_related()for reverse relations or M2M fields
Slow Queries
Common causes of slow queries:
- COUNT on complex DISTINCT: Pagination wrapping complex visibility subqueries
- Fix: Materialize IDs in Python first, then filter with simple
INclause
- Fix: Materialize IDs in Python first, then filter with simple
- Missing indexes: Full table scans
- Fix: Add database indexes on filtered/joined columns
- Complex JOINs: Multiple related tables
- Fix: Optimize query structure or denormalize if appropriate
Timeline Analysis
The timeline shows query execution order with visual bars:
1. + 0.0ms [ 2.5ms] █ "accounts_reveluser"
7. + 60.2ms [ 2.8ms] █ "__count"Look for:
- Large gaps between queries (indicates Python processing time)
- Queries that could run in parallel but are sequential
- Expensive queries that block subsequent operations
Common Optimization Patterns
Expensive COUNT with DISTINCT
When you see:
SELECT COUNT(*) FROM (SELECT DISTINCT ... complex subquery ...)Fix by materializing IDs:
# Before (slow COUNT)
qs = Event.objects.for_user(user).filter(...).distinct()
# After (fast COUNT)
event_ids = list(Event.objects.for_user(user).values_list("id", flat=True).distinct())
qs = Event.objects.full().filter(id__in=event_ids)Redundant Visibility Checks
When the same for_user() query appears multiple times:
- Create a method that accepts already-checked objects
- Cache visibility results within the request
Show full SKILL.md (166 more words)Show less
Batch Operations
When creating multiple objects:
- Use
bulk_create()instead of individual.save()calls - Fetch shared data (settings, related objects) once before the loop
- Send notifications in batches, not per-item
CLI Options Reference
Single Request Analysis
--full, -f: Run all analyses--duplicates, -d: Show N+1 candidates--slow, -s: Show slow queries--slow-threshold N: Slow query threshold in ms (default: 5)--tables, -t: Group queries by table--timeline: Show execution timeline--traceback, -tb: Show code locations for duplicates--profile, -prof: Show Python cProfile data
Listing and Filtering
--list, -l: List requests--limit N: Number of results (default: 20)--sort {recent,queries,duration,db_time}: Sort order--path, -p: Filter by path (contains)--method, -m: Filter by HTTP method--status: Filter by status code--min-queries N: Minimum query count--min-time N: Minimum response time (ms)--min-db-time N: Minimum DB time (ms)
Aggregate Views
--stats: Show aggregate statistics--endpoints: Show endpoint summary with P95--slow-endpoints: Group slow requests by endpoint--slow-endpoint-threshold N: Threshold in ms (default: 200)--min-count N: Minimum requests for endpoint summary
© letsrevel, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in .claude/skills/silk-debug of letsrevel/revel-backend.
Open the folder on GitHubat commit ae56c86
Compare with similar skills
Silk Debug next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Silk Debug this skillletsrevel/revel-backend | 109 | — | ~1.2k | Automated safety check: Pass | MIT | |
| Profiling Slow API EndpointsPostHog/posthog-foss | 721 | — | ~1k | Automated safety check: Pass | MIT | |
| Assess Migrationmendixlabs/mxcli | 128 | — | ~3.6k | Automated safety check: Notes | Apache-2.0 | |
| Django Q2hashgraph-online/awesome-codex-plugins | 1.2k | — | ~1.7k | Automated safety check: Pass | MIT | |
| Backend Analysis Skilljiushiwon/wg-skills | 110 | — | ~1k | Automated safety check: Pass | Apache-2.0 | |
| Django DB Performancehashgraph-online/awesome-codex-plugins | 1.2k | — | ~888 | Automated safety check: Pass | MIT |
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Questions about Silk Debug
What does Silk Debug do?
Analyze Django Silk profiling data to debug slow requests, detect N+1 queries, and optimize database performance. Silk Debug is an agent skill from letsrevel/revel-backend. Analyze Django Silk profiling data to debug slow requests, detect N+1 queries, and optimize database performance.
When should I use Silk Debug?
Silk Debug fits situations like: analyzing request IDs; investigating slow endpoints; optimizing query performance.
How do I install Silk Debug in Claude Code?
Run `npx skills add letsrevel/revel-backend --skill silk-debug -a claude-code`. Or copy the skill folder (.claude/skills/silk-debug in letsrevel/revel-backend) into .claude/skills/silk-debug in your project. Claude Code loads it when a task matches its description.
How do I install Silk Debug in Codex?
Run `npx skills add letsrevel/revel-backend --skill silk-debug -a codex`. Or copy the skill folder (.claude/skills/silk-debug in letsrevel/revel-backend) into .agents/skills/silk-debug in your project. Codex loads it when a task matches its description.
Can I use Silk Debug in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add letsrevel/revel-backend --skill silk-debug -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/silk-debug, .gemini/skills/silk-debug, .github/skills/silk-debug and .opencode/skills/silk-debug in your project.
What does Silk Debug need to run?
Going by SKILL.md and its folder, Silk Debug needs the command-line tools its instructions call (python). Our summary lists: Python 3. Its frontmatter pre-approves these tools: Bash(python:*), Bash(.venv/bin/python:*), Read, Grep.
Does Silk Debug access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Silk Debug safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Silk Debug use?
Silk Debug is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Silk Debug use?
About 1.2k tokens (SKILL.md is roughly 5k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Silk Debug?
Skills that share tags, products or a category with Silk Debug: Profiling Slow API Endpoints (PostHog/posthog-foss, 721 stars), Assess Migration (mendixlabs/mxcli, 128 stars), Django Q2 (hashgraph-online/awesome-codex-plugins, 1.2k stars) and Backend Analysis Skill (jiushiwon/wg-skills, 110 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Silk Debug?
letsrevel (a GitHub organization) maintains it in letsrevel/revel-backend, which has 109 GitHub stars. The repository holds 5 skills in this directory. The repository was last updated on October 6, 2026.
Source: letsrevel/revel-backend on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.