What is atproto-identity-resolution?

A guide for resolving AT Protocol identities: human-readable handles such as alice.bsky.social and permanent identifiers called DIDs. It covers Rust, TypeScript, and Go implementations.

Use it when implementing or debugging identity lookup, handle validation, DID document retrieval, or identity parsing in an AT Protocol application.

It helps convert handles and DIDs correctly, fetch the right identity documents, and validate that the returned identity matches the account.

atproto-identity-resolution — Skill for Claude Code by ngerakines

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add ngerakines/atproto-skills --skill atproto-identity-resolution

Clone the repo

git clone --depth 1 https://github.com/ngerakines/atproto-skills

Made for: Claude Code.

Or install atproto-skills, the plugin that ships this one along with the rest of its 7 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/ngerakines/atproto-skills/atproto-identity-resolution/github.svg)](https://agentmods.dev/skills/ngerakines/atproto-skills/atproto-identity-resolution)

Your own site

<a href="https://agentmods.dev/skills/ngerakines/atproto-skills/atproto-identity-resolution"><img src="https://agentmods.dev/badge/skills/ngerakines/atproto-skills/atproto-identity-resolution/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/ngerakines/atproto-skills/atproto-identity-resolution"><img src="https://agentmods.dev/badge/skills/ngerakines/atproto-skills/atproto-identity-resolution.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 587 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 4,052 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00587	$0.04052
Opus 5.5	$0.00235	$0.01621
Sonnet 5.5	$0.00117	$0.00810
Haiku 4.5	$0.00059	$0.00405

Measured 2mo ago against content hash 91d69c0ebc02, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

atproto-identity-resolution scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/atproto-identity-resolution/SKILL.md · 194 lines

How it starts

The opening of the file, as written. The whole thing — 194 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AT Protocol Identity Resolution

Every AT Protocol account is a DID; most accounts also have a human-friendly handle. Turning either one into the other — and trusting the result — is the bedrock operation this skill covers. This file is a router that sits on top of a language-neutral spec in shared/ and per-language guides in rust/, typescript/, go/.

Defaults

An atproto identity resolution pipeline always does the same four things:

Normalize and classify the input (at://, @, whitespace stripped; then handle vs DID by prefix).
Resolve handle → DID using DNS TXT (_atproto.<handle>) and HTTPS (/.well-known/atproto-did) concurrently (the spec requires it; Rust uses tokio::join!, TypeScript races, Go's reference library currently runs sequentially and is a divergence — see shared/handle-spec.md §4.3 and shared/divergence-matrix.md), with a documented conflict policy.
Fetch the DID document via the method-specific transport (did:plc → PLC directory, did:web → host well-known, did:webvh → log + verifier).
Validate the document and bidi-check: alsoKnownAs contains at://<handle>, a #atproto Multikey is present, an #atproto_pds AtprotoPersonalDataServer service is present.

Anything outside those four steps (rotation keys, PLC operation logs, OAuth, records) belongs in an adjacent skill — see the frontmatter.

Full normative rules: shared/handle-spec.md and shared/did-spec.md. End-to-end sequence: shared/resolution-flow.md. Fixtures: shared/test-vectors.md. Cross-language differences: shared/divergence-matrix.md.

Language detection

Before generating or reviewing identity-resolution code, determine the target language from project files or the file being edited:

Cargo.toml, *.rs, rust-toolchain.toml, any mention of atproto-identity (crate) → Rust — read from rust/.
package.json, tsconfig.json, *.ts, *.tsx, imports of @atproto/identity / @atproto/syntax / @atproto-labs/handle-resolver → TypeScript — read from typescript/. Also *.js/*.jsx when there is no .ts present in the repo.
go.mod, *.go, imports of github.com/bluesky-social/indigo/atproto/identity or .../atproto/syntax → Go — read from go/.

Read the full file on GitHub · 194 lines

Files

What ships with it

17 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 194 lines · 0 tokens per session scan A 91d69c0ebc02

Subscribe to this mod's changes

atproto-identity-resolution is a skill published in the GitHub repository ngerakines/atproto-skills (53 stars, last pushed 6mo ago), licensed MIT. It adds 587 tokens to every session and 4,052 once invoked, about $0.0023 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Backend and APIs agentskills atproto atprotocol

atproto-identity-resolution next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
atproto-identity-resolutionngerakines/atproto-skills	Skill	53	6mo ago	MIT	A	587	Claude Code
litellmmagnus919/agent-skills	Skill	166	2d ago	MIT	A	173	Claude Code, Codex
emailmagnus919/agent-skills	Skill	166	2d ago	MIT	A	135	Claude Code, Codex
supabasemagnus919/agent-skills	Skill	166	2d ago	MIT	A	94	Claude Code, Codex
api-testingpetrkindlmann/qa-skills	Skill	250	15d ago	MIT	A	129	Claude Code, Codex
vercel-evemagnus919/agent-skills	Skill	166	2d ago	MIT	A	99	Claude Code, Codex
spring-aimagnus919/agent-skills	Skill	166	2d ago	MIT	A	80	Claude Code, Codex