DeepSeek Harness is an open-source framework for building and running AI agents, organized so that its functionality is provided through plugins. Developers use it to launch agent workflows through a local web interface or from source, while the catalogue add-ons extend the harness as plugins.
Borrowing it
Nothing to install: this file belongs to deepseek-ai/deepseek-harness. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/deepseek-ai/deepseek-harness/master/.agents/skills/dsh-session-projection/SKILL.mdgit clone --depth 1 https://github.com/deepseek-ai/deepseek-harnessWrote 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.
[](https://agentmods.dev/skills/deepseek-ai/deepseek-harness/dsh-session-projection)<a href="https://agentmods.dev/skills/deepseek-ai/deepseek-harness/dsh-session-projection"><img src="https://agentmods.dev/badge/skills/deepseek-ai/deepseek-harness/dsh-session-projection/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.
<a href="https://agentmods.dev/skills/deepseek-ai/deepseek-harness/dsh-session-projection"><img src="https://agentmods.dev/badge/skills/deepseek-ai/deepseek-harness/dsh-session-projection.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00030 | $0.00897 |
| Opus 5.5 | $0.00012 | $0.00359 |
| Sonnet 5.5 | $0.00006 | $0.00179 |
| Haiku 4.5 | $0.00003 | $0.00090 |
Grade A, and why
dsh-session-projection 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 yesterday.
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.
How it starts
The opening of the file, as written. The whole thing — 31 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Session Projection Rules
Summary
Keep recoverable session facts in Projection and expose them through their owning services. Read the API and lifecycle for the supported preparation, registration, read, and cleanup contracts.
-
Put all persisted or restorable session-derived state in Projection, including host-only state. Reuse an existing owner when suitable. Keep external resources and process-scoped ownership outside persisted state. Persist facts, not registration handles, promises, or runtime resources.
-
Do not expose projection definitions or handles as production read APIs. Keep the ready handle private; consumers use the owning service's domain methods. A handle is a process-local reader, recreated during activation. Require
sessionProjectionswhen the service depends on it; optional registration is only for optional contributions. Do not hide a missing required dependency with another recovery path. -
State recovery through
initandapplyis synchronous and deterministic. Do not perform I/O or trigger Cordis hooks, models, or tools. Runtime hooks own those effects. Replay must not repeat them. Return the same state reference for unrelated events. Keep views synchronous and preserve their references when visible values do not change. -
Persist JSON state that its schema accepts. Follow the README's state-version and checkpoint-watermark rules. Restoring a checkpoint and replaying its suffix must match full replay. Change the version when state fields or recovery semantics change.
-
Prefer fixed-size or sublinear state. Growth is acceptable only when slow enough to remain negligible. Necessary linear state must have a current use and explicit memory, replay, and per-event costs. Do not retain history-sized indexes, including event sequence collections, by habit. Do not discard required data or change behavior to reduce size. Start with a complete implementation; optimize for a concrete need.
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.
- yesterday First seen · 31 lines · 30 tokens per session scan A 31d8610d1f8e
dsh-session-projection is a skill published in the GitHub repository deepseek-ai/deepseek-harness (260,751 stars, last pushed yesterday), licensed MIT. It adds 30 tokens to every session and 897 once invoked, about $0.0001 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 2026-10-24.
Other skills, from other repositories
manage-taskboard
Manage work in the native DeepSeek Harness Taskboard with exact task ids and optimistic versions. Use when an Agent must inspect project work, claim an eligible todo, record progress or blockers, verify an implementation, submit it for human review, or release its own claim; also use when a human asks how to accept…
industry-research-method
A Chinese-language method for researching an industry by mapping its supply chain, tracking policies and news, and writing sourced reports. It separates the chain into upstream inputs, midstream production, and downstream distribution or use.
company-research-method
A documented process for researching a company using supplied files and selected public sources. It produces a company overview with business details, sourced financial figures, and stated risks.
dsh-plugin-guide
Use when developing, reviewing, packaging, debugging, or answering questions about DeepSeek Harness (DSH) plugins — the plugin-based agent harness on vendored Cordis. Applies the official plugin-development constraints (plugin contract, cordis.yml layers, services/events/effects, tool DSL, bundles/profiles) backed by…
setup-matt-pocock-skills
Configure this repo for the engineering skills: set up its issue tracker, triage label vocabulary, and domain doc layout. Run once before first use of the other engineering skills.
wayfinder
Plan a huge chunk of work (more than one agent session can hold) as a shared map of decision tickets on your issue tracker, and resolve them one at a time until the way to the destination is clear.