neograph-dev-checkpoint

neograph-dev-checkpoint is a skill for Claude Code, Codex from postindustria-tech/agentic-toolkit. It costs 69 tokens per session (1,119 once invoked), scanned A, original, MIT.

A skill for Neograph's checkpoint system, which resumes interrupted workflows by detecting changed data structures and rerunning only affected steps. A checkpoint is saved progress that can be resumed or rewound.

In plain words
What is it for?
Use it when working on checkpoint resume, time travel, rewind, schema changes, per-node invalidation, or CheckpointSchemaError issues.
Why use it?
It explains how schema fingerprints identify changes and help avoid rerunning unaffected workflow nodes.

Skill for Claude CodeCodex

Part of the neograph-dev plugin — 6 skills shipped together

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.

agentmods
npx agentmods add skills/postindustria-tech/agentic-toolkit/neograph-dev-checkpoint
Any agent
npx skills add postindustria-tech/agentic-toolkit --skill neograph-dev-checkpoint
Clone the repo
git clone --depth 1 https://github.com/postindustria-tech/agentic-toolkit

Made for: Claude Code, Codex.

Or install neograph-dev, the plugin that ships this one along with the rest of its 6 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.

agentmods badge for neograph-dev-checkpoint

README.md
[![agentmods](https://agentmods.dev/badge/skills/postindustria-tech/agentic-toolkit/neograph-dev-checkpoint.svg)](https://agentmods.dev/skills/postindustria-tech/agentic-toolkit/neograph-dev-checkpoint)
Your own site
<a href="https://agentmods.dev/skills/postindustria-tech/agentic-toolkit/neograph-dev-checkpoint"><img src="https://agentmods.dev/badge/skills/postindustria-tech/agentic-toolkit/neograph-dev-checkpoint.svg" alt="Measured on agentmods" height="20"></a>
Per session 69 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,119 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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.

ModelPer sessionOnce invoked
Fable 5 $0.00069 $0.01119
Opus 5 $0.00034 $0.00560
Sonnet 5 $0.00014 $0.00224
Haiku 4.5 $0.00007 $0.00112

Measured 3d ago against content hash a30fbf3e8a67, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

neograph-dev-checkpoint 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 3d 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.

plugins/neograph-dev/skills/neograph-dev-checkpoint/SKILL.md · 125 lines

How it starts

The opening of the file, as written. The whole thing — 125 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Neograph Checkpoint System

Schema-aware checkpoint resume that automatically detects what changed and re-executes only affected nodes. Based on the Prefect cache-miss model.

Schema Fingerprinting

Two fingerprint functions in state.py:

compute_schema_fingerprint(state_model) -- state.py:298

SHA-256 prefix (16 chars) of sorted (field_name, annotation_string) pairs. Excludes framework fields (neo_*, node_id, project_root, human_feedback). Changes when any field is added/removed or its type changes.

compute_node_fingerprints(construct) -- state.py:262

dict[str, str] mapping each node's state field name to a SHA-256 prefix (12 chars). Hash input: "{field_name}:{type.__qualname__}". For dict-form outputs (multi-output): one fingerprint per output key. For sub-constructs: fingerprinted by their output type.

Compile-Time Attachment

compiler.py:204-205 stashes both fingerprints on the compiled graph:

compiled._neo_schema_fingerprint = compute_schema_fingerprint(state_model)
compiled._neo_node_fingerprints = compute_node_fingerprints(construct)

Run-Time Injection

runner.py:267-272 injects fingerprints into the initial state dict so they persist in the checkpoint alongside node outputs.

Resume Flow

_verify_checkpoint_schema() in runner.py:74-127:

  1. Read stored neo_schema_fingerprint from checkpoint channel_values
  2. Compare against current _neo_schema_fingerprint on the compiled graph
  3. If match: resume normally
  4. If mismatch:
    • _compute_invalidated_nodes() diffs per-node fingerprints
    • auto_resume=True: call _auto_resume_from_divergence()
    • auto_resume=False: raise CheckpointSchemaError(invalidated_nodes=...)

Auto-Resume: The LangGraph Time-Travel Pattern

_auto_resume_from_divergence() in runner.py:129-154:

  1. Walk graph.get_state_history(config) backwards (newest to oldest)
  2. Find the snapshot where an invalidated node appears in .next (meaning "this checkpoint was taken just before that node ran")
  3. Extract checkpoint_id from that snapshot's config
  4. Mutate caller's config["configurable"]["checkpoint_id"] in-place
  5. Back in run(), graph.invoke(None, config=config) resumes from rewind point
  6. LangGraph naturally re-executes from the rewind point forward

Read the full file on GitHub · 125 lines

Files

What ships with it

1 file 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.

  1. 3d ago First seen · 125 lines · 69 tokens per session scan A a30fbf3e8a67

Subscribe to this mod's changes

neograph-dev-checkpoint is a skill published in the GitHub repository postindustria-tech/agentic-toolkit (2 stars, last pushed 1mo ago), licensed MIT. It adds 69 tokens to every session and 1,119 once invoked, about $0.0003 per session on Opus 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 2026-08-31.

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