| name | methodology |
| version | 0.3.0 |
| description | Analyzes captured HTTP traffic, designs the CLI architecture, and implements the Python CLI package (Phase 2): parse raw-traffic.json, identify the protocol, write api-spec.json, scaffold from templates, and implement endpoint methods and Click command groups. Use after a capture completes and raw-traffic.json exists.
|
| when_to_use | Trigger phrases: "analyze traffic", "design CLI", "implement CLI", "build CLI from network traffic", "generate API wrapper", "reverse engineer web API", "start Phase 2", or after the capture skill finishes. Not for traffic recording (capture), test writing (testing), or quality checks (standards).
|
CLI-Anything-Web Methodology (Phase 2)
Analyze captured traffic, design the CLI command structure, and implement the
complete Python CLI package. This skill owns the core transformation from raw
HTTP traffic to a production-ready CLI.
Copy this checklist and check off items as you complete them:
Phase 2 Progress:
- [ ] Prerequisites: raw-traffic.json exists (+ auth state if the site needs auth)
- [ ] Step A: traffic analyzed, protocol identified, <APP>.md written
- [ ] Step A: api-spec.json written (every endpoint cites raw-traffic.json evidence)
and passes `cli-web-devkit spec validate`
- [ ] Step B.0: scaffolded via scaffold-cli.py (.manifest.json present)
- [ ] Step B: client endpoint methods implemented from the spec
- [ ] Step B: command modules implemented + registered, REPL help in sync
- [ ] Smoke check passed (no protocol leaks), phase-state marked complete
Prerequisites (Hard Gate)
Do NOT start unless:
If raw-traffic.json is missing or has no WRITE operations, invoke the
capture skill first. If Phase 1 state shows failed, follow
skills/shared/RECOVERY.md §phase-state Check Failures before re-running.
Exception for read-only sites: If the site is genuinely read-only (search engine,
dashboard, analytics viewer with no create/update/delete), the trace may contain only
GET requests. In this case, note "read-only site — no write operations" in <APP>.md
and proceed. The generated CLI will have read-only commands (list, get, search) but
no create/update/delete commands. This is valid.
No-auth sites: If the target site requires no authentication (public API,
no login needed), the "Auth state captured" prerequisite does not apply. Note
"no-auth site" in <APP>.md and proceed.
Step A: Analyze (API Discovery)
Goal: Map raw traffic to a structured API model.
Process:
-
Read traffic-analysis.json first (if it exists alongside raw-traffic.json).
This file is auto-generated by parse-trace.py or mitmproxy-capture.py → analyze-traffic.py and contains
pre-detected protocol type, auth pattern, endpoint grouping, GraphQL operations,
batchexecute RPC IDs, and suggested CLI commands. Use it as a starting point —
verify its findings and fill in anything marked "unknown" by reading raw-traffic.json
manually.
Enhanced analysis (present only when captured via mitmproxy):
request_sequence (timeline-ordered requests with auth-flow detection),
session_lifecycle (cookie inventory, auth-cookie identification, session
pattern), and endpoint_sizes (response-size classification). If these
are missing (has_timestamps: false), the capture came from the default
trace path — rely on manual analysis for sequence/session detail.
If traffic-analysis.json doesn't exist, run the analyzer:
python ${CLAUDE_PLUGIN_ROOT}/scripts/analyze-traffic.py \
<app>/traffic-capture/raw-traffic.json --summary
-
Parse raw-traffic.json (for details the analyzer couldn't extract)
-
Group requests by base path (e.g., /api/v1/boards/, /api/v1/items/)
-
For each endpoint group, identify:
- HTTP method (GET/POST/PUT/DELETE/PATCH)
- URL pattern (extract path parameters like
:id)
- Query parameters and their types
- Request body schema (JSON fields, types, required/optional)
- Response body schema
- Authentication method (Bearer token, cookie, API key)
- Rate limiting signals (429 responses, retry-after headers)
-
Identify RPC protocol type -- classify the API transport:
| Protocol | Detection Signal | Client Pattern |
|---|
| REST | Resource URLs (/api/v1/boards/:id), standard HTTP methods | client.py with method-per-endpoint |
| GraphQL |
Output: <APP>.md (human SOP) + api-spec.json (machine spec, validated).
References: traffic-patterns.md, google-batchexecute.md, ssr-patterns.md
Step B: Implement (Code Generation)
Study Existing CLIs First (Critical for Accuracy)
Before implementing, read an existing CLI that uses the same protocol as your
target. These are battle-tested implementations that solved the same problems you'll face.
| Protocol | Reference CLI | Key files to read |
|---|
| Google batchexecute | notebooklm/agent-harness/cli_web/notebooklm/ | core/rpc/encoder.py, core/rpc/decoder.py, core/client.py, core/auth.py |
| GraphQL + WAF | booking/agent-harness/cli_web/booking/ | core/client.py (curl_cffi + GraphQL), core/auth.py (WAF tokens) |
| HTML scraping | futbin/agent-harness/cli_web/futbin/ | core/client.py (httpx + BS4), commands/players.py |
| Next.js RSC | producthunt/agent-harness/cli_web/producthunt/ | core/client.py (curl_cffi + __next_f flight parsing) |
| REST API | unsplash/agent-harness/cli_web/unsplash/ | core/client.py, commands/photos.py |
| Simple HTML | gh-trending/agent-harness/cli_web/gh_trending/ | Minimal structure example |
How to use reference CLIs:
- Read the reference CLI's
core/client.py — understand the request/response pattern
- Read
core/auth.py — copy the login_browser() pattern exactly for Google apps
- Read
core/rpc/ (for batchexecute) — understand encoder/decoder, DO NOT reinvent
- Read
commands/ — see how Click commands are structured, how --json works
- Read
utils/helpers.py — see handle_errors(), _resolve_cli(), repl patterns
For batchexecute apps specifically, the notebooklm CLI is your bible:
- Copy the encoder/decoder architecture (don't reinvent the batchexecute wire format)
- Copy the auth token extraction pattern (CSRF, session ID, build label)
- Copy the cookie domain priority logic (critical for Israeli/international users)
- Adapt the RPC method IDs and param structures to your target app
The agent implementing the CLI MUST read these files before writing code. Use the
Agent tool to dispatch a research agent that reads
the reference implementation while you design the command structure.
Design Before You Code
Before writing any code, note the command structure in <APP>.md (10 minutes max):
- Map each API endpoint group to a Click command group:
/api/v1/boards/* → boards command group
/api/v1/items/* → items command group
- Map CRUD operations to subcommands (GET list →
list, GET single → get,
POST → create, PUT/PATCH → update, DELETE → delete)
- Note auth design:
auth login, auth status, auth refresh; credentials at
~/.config/cli-web-<app>/auth.json
- Note REPL design: bare command enters REPL, branded banner via
repl_skin.py
Goal: Generate the complete Python CLI package.
Package Structure
See HARNESS.md "Generated CLI Structure" for the complete package template.
Key points: cli_web/ namespace (NO __init__.py), <app>/ sub-package (HAS __init__.py),
core/, commands/, utils/, tests/ directories.
Step B.0: Scaffold Core Modules
Run the scaffold generator script (v2 — Jinja2 templates, requires
pip install jinja2) to create all boilerplate files:
python ${CLAUDE_PLUGIN_ROOT}/scripts/scaffold-cli.py <app>/agent-harness \
--app-name <app> \
--protocol <rest|graphql|html-scraping|batchexecute> \
--http-client <httpx|curl_cffi> \
--auth-type <none|cookie|api-key|google-sso> \
--resource <name> [--resource <name> ...] \
[--has-polling] [--has-context] [--has-partial-ids]
This renders exceptions.py, client.py skeleton, the unified auth.py (google-sso
handled via a template conditional), helpers.py, config.py, output.py, the CLI
entry point with REPL, one commands/<resource>.py per --resource flag,
setup.py, conftest.py, test_e2e.py skeleton, README/SKILL skeletons,
repl_skin.py, and (for batchexecute) the rpc/ subpackage. It also writes
.manifest.json (template version + profile) at the harness root — keep it;
fleet tooling depends on it. See skills/boilerplate/SKILL.md for the
template → output map and per-profile flag recipes.
Fallback: If the script is unavailable, follow
skills/shared/RECOVERY.md §scaffold-cli.py Unavailable — adapt from the
newest generated CLI (e.g., capitoltrades/agent-harness/), do NOT
reconstruct boilerplate from memory.
After scaffolding, review the generated files and customize client.py with actual
endpoint methods from <APP>.md.
Implementation Rules
All rules below are DEFINED in skills/shared/CONVENTIONS.md — this section
tells you when to apply them during implementation.
-
exceptions.py -- implement first. Required hierarchy and error-code mapping: CONVENTIONS.md §Exception Hierarchy. Complete code: references/exception-hierarchy-example.py.
-
client.py -- HTTP client with exception mapping and auth retry:
- HTTP library choice:
- Centralized auth header/cookie injection
- Automatic JSON parsing with response body verification
- Status code → exception mapping: 401/403→
AuthError, 404→NotFoundError, 429→RateLimitError, 5xx→ServerError (CONVENTIONS.md §Exception Hierarchy)
- Auth retry (3-attempt auto-refresh): current cookies → reload
auth.json → headless refresh, never more. The full table is CONVENTIONS.md §Auth Rules; the templates generate it by default.
- Exponential backoff for rate limits (CONVENTIONS.md §Exponential Backoff & Polling; code in
references/polling-backoff-example.py)
- For apps with 3+ resource types: split into namespaced sub-clients (
client.notebooks.list(), client.sources.add())
- See
references/client-architecture-example.py for the full pattern
-
auth.py -- handles token storage, refresh, expiry. Implementation depends on auth type:
For no-auth sites: DO NOT create auth.py, session.py, or auth command groups.
These files are dead code for public APIs and confuse users. The CLI should have
NO auth-related files or commands. The only exception is if the site has optional
auth (e.g., API key for write operations) — in that case, implement a minimal
auth module.
Not all helpers apply to every CLI. Include only what the CLI uses:
handle_errors and print_json are always needed. resolve_partial_id only
for UUID-based apps. require_notebook/context helpers only for apps with
persistent context. poll_until_complete only for generation/async operations.
REPL Implementation Rules (Critical)
The four REPL rules are defined with code examples in
CONVENTIONS.md §REPL Rules — apply them as you wire up <app>_cli.py:
- Parse REPL lines with
shlex.split(line), never line.split().
- Propagate
--json by PREPENDING it to the args list passed to
cli.main(args=..., standalone_mode=False) — never **ctx.params.
- Help-sync: every commit that adds a command/option updates
_print_repl_help() in the same commit.
- Required single values are
@click.argument positionals, not
@click.option(..., required=True).
These bugs appear in almost every generated REPL — read the §REPL Rules
section before writing the entry point, not after the REPL breaks.
Parallel Implementation (dispatch independent modules as subagents)
When the CLI has 3+ command groups (e.g., notebooks, sources, chat, artifacts),
dispatch parallel subagents -- one per command module. Each agent gets:
- The
<APP>.md API spec for its resource
- The
client.py and auth.py interfaces it depends on
- Clear scope: "Implement
commands/notebooks.py with list, get, create, delete"
Parallelization opportunities:
| Independent from each other | Dispatch in parallel |
|---|
commands/notebooks.py, commands/sources.py, commands/chat.py | Yes -- each command file only depends on client.py |
rpc/encoder.py and rpc/decoder.py | Yes -- encoder doesn't depend on decoder |
auth.py and models.py | Yes -- no shared logic |
client.py and commands/* | No -- commands depend on client |
<app>_cli.py (entry point) | Last -- imports all commands, write after they're done |
Implementation order (with maximum parallelism):
Phase A (sequential): Write core foundation
exceptions.py → client.py → auth.py (if needed) → models.py
Phase B (parallel): Dispatch ALL independent work simultaneously
┌─ Agent 1: commands/notebooks.py
├─ Agent 2: commands/sources.py
├─ Agent 3: commands/chat.py
├─ Agent 4: commands/artifacts.py
├─ Agent 5: rpc/encoder.py + rpc/decoder.py (if non-REST)
└─ Agent 6 (background): test_core.py (unit tests for core modules)
All run concurrently — each only depends on Phase A modules
Phase C (sequential): Wire everything together
utils/helpers.py → <app>_cli.py → __main__.py → setup.py
(repl_skin.py, doctor.py, mcp_server.py were already vendored by
scaffold-cli.py in Step B.0; the entry point registers doctor + mcp-serve)
Key parallelism rules:
- Dispatch independent command modules as parallel subagents (one per
commands/*.py file)
- Start unit test writing as a background agent during command implementation
- Entry point (
<app>_cli.py, setup.py) must come last (depends on all commands)
Mandatory Smoke Check (Before Testing Phase)
Before invoking testing, install (pip install -e .) and verify:
cli-web-<app> --help loads
cli-web-<app> auth status --json shows valid (if auth-required)
cli-web-<app> <resource> list --json returns real data
- One WRITE command works (if applicable)
Red flags — fix before testing: the full table is CONVENTIONS.md
§Protocol-Leak Smoke Check (wrb.fr/af.httprm leaks, empty []/null,
parser index mismatches). One methodology-specific case: a null WRITE response
may mean the operation is client-side — see references/google-batchexecute.md
"Client-Side Operations".
Update phase state:
python ${CLAUDE_PLUGIN_ROOT}/scripts/phase-state.py complete <app> \
--phase methodology --output <app>/agent-harness/
Next Step
When implementation is complete and the smoke check passes, invoke the testing
skill to plan and write tests.
Do NOT skip testing -- every CLI must have comprehensive tests before publishing.
Companion Skills
| Skill | When it activates |
|---|
capture | Phase 1 -- traffic recording (prerequisite for this skill) |
testing | Phase 3 -- test writing, documentation |
standards | Phase 4 -- publish, verify, smoke test |
Integration
| Relationship | Skill |
|---|
| Preceded by | capture (Phase 1) |
| Followed by | testing (Phase 3) |
| References | skills/shared/CONVENTIONS.md (all rules), skills/shared/RECOVERY.md (gate failures), traffic-patterns.md, auth-strategies.md, google-batchexecute.md, ssr-patterns.md, exception-hierarchy-example.py, client-architecture-example.py, polling-backoff-example.py, rich-output-example.py |
Reference Files
references/traffic-patterns.md -- Common API patterns (REST, GraphQL, RPC)
references/auth-strategies.md -- Auth implementation strategies
references/google-batchexecute.md -- Google batchexecute RPC protocol spec
references/ssr-patterns.md -- SSR framework patterns and data extraction strategies
references/exception-hierarchy-example.py -- Complete exception hierarchy with HTTP status mapping
references/client-architecture-example.py -- Namespaced sub-client pattern with auth retry
references/polling-backoff-example.py -- Exponential backoff polling and rate-limit retry
references/rich-output-example.py -- Rich progress bars, JSON error responses, table formatting