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lettr-comlettr-com/lettr-skills/diagnose/SKILL.md

diagnose

Skill0 starsChanged 5 months agoMITView on GitHub

Use when emails are not delivering, a domain won't verify, a webhook is silent, or rate limits/quotas are firing. Triage flow pairs each symptom with the right diagnostic step and a reference for interpreting the result.

193 other projects use a version of this.

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Projects with it also use zoom-out, to-prd and 10 more.

Other files people use alongside this one.

Files found in the same public projects as a version of this one, more often than they turn up anywhere else. Each project counts once, large collections count for less, and this file's own repository is left out.
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    Break a plan, spec, or PRD into independently-grabbable issues on the project issue tracker using tracer-bullet vertical slices.

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    edit-article

    The user will invoke this skill to help them edit an article.

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    Create new agent skills with proper structure, progressive disclosure, and bundled resources. Use when user wants to create, write, or build a new skill.

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  • AnasX7Skill

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    Set up Husky pre-commit hooks with lint-staged (Prettier), type checking, and tests in the current repo. Use when user wants to add pre-commit hooks, set up Husky, configure lint-staged, or add commit-time formatting/typechecking/testing.

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  • +4 more from simo97

The file

We split this skill into the rules it gives an agent

2 rules. 0 are common, 0 are distinctive, and 2 are very specific to this project.

  • 0

    Common

    Most of the 174 edited versions we read keep these.

  • 0

    Distinctive

    This author's own choices. Worth a look.

  • 2

    Very specific

    Tied to their project's names, files or tools. Probably skip.

  • Common
  • Distinctive
  • Very specific
  1. Very specific:

    Reproduce by request_id when possible: If the user has a request_id from a recent send, fetch its event timeline first — it's the cheapest …

    line 25
  2. Very specific:

    Confirm setup before suspecting bugs: If a fresh integration is misbehaving, validate the API key and list domains first.

    line 28

“Common” is measured: kept by at least 6 in 10 of the 174 edited versions of this file we could read. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

Keep what fits and drop the rest. Your version, ready for your agents.
Files
SKILL.md

Diagnose Lettr delivery problems

The job is interpretation. Fetch the relevant data from Lettr, then read the result against the references in this skill to tell the user what's wrong and how to fix it.

Triage by symptom

Pick the row that matches what the user is reporting.

SymptomWhat to fetchReference
"I sent an email, the user never got it"Email events filtered by recipient (last hour)bounce-classes.md, webhook-events.md
"I get 400 unconfigured_domain / domain rejected when sending"Domain list, then details for the failing onedns-failures.md
"I added a domain but it stays pending"Trigger verification, then re-fetch the domaindns-failures.md
"Webhook isn't firing for my events"Webhook list, then details for the suspect onewebhook-events.md
"I'm getting 429 / quota exceeded"Validate API key, then read the response payloadquota-rate-limits.md
"Open / click tracking shows nothing"Event detail for one known sendwebhook-events.md — engagement events

General flow

  1. Reproduce by request_id when possible. If the user has a request_id from a recent send, fetch its event timeline first — it's the cheapest lookup.
  2. Otherwise filter by recipient. Pull email events filtered by the affected address, narrowed to the relevant time window.
  3. Read the latest event. The chronologically last event is usually decisive. delivery means the receiving server accepted it (problem is downstream — spam folder, user error). bounce, policy_rejection, out_of_band, or delay mean Lettr couldn't or didn't fully deliver — read the reference to interpret the class.
  4. Confirm setup before suspecting bugs. If a fresh integration is misbehaving, validate the API key and list domains first. Most early-stage problems are unverified domains or from addresses on the wrong domain.

What this skill does NOT do

  • It does not read user mailboxes. If a user reports "I didn't get the email" but Lettr shows delivery, the message is in their inbox/spam — the user must check.
  • It does not repair DNS at the user's registrar. The skill explains what's wrong; the user fixes it at Cloudflare/Route53/etc.

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