vera AGENTS.md

Repository instructions for Vera, a programming language with contracts, effects, and verification checks. They explain how agents should write Vera code and use its conformance examples.

In plain words
What is it for?
They help write, parse, check, verify, and run Vera programs, and use the conformance suite as a reference.
Why use it?
They provide tested examples and rules for avoiding language mistakes, including programs that are deliberately expected to fail.

Instructions file for CodexOpenCode

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 instructions/aallan/vera/agents-md
Clone the repo
git clone --depth 1 https://github.com/aallan/vera

Made for: Codex, OpenCode.

Per session 4,376 This file is loaded in full into every session.
When invoked 4,376 The same file — it is already loaded in full.
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 $0.04376 $0.04376
Opus 5 $0.02188 $0.02188
Sonnet 5 $0.00875 $0.00875
Haiku 4.5 $0.00438 $0.00438

Measured 2d ago against content hash e2b0001c1fb3, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

vera AGENTS.md 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 2d 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.

AGENTS.md · 218 lines

How it starts

The opening of the file, as written. The whole thing — 218 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md — Instructions for AI agents

This document is for AI agents working with the Vera codebase. There are two audiences: agents writing Vera code, and agents working on the compiler.

For agents writing Vera code

Read SKILL.md for the full language reference. It covers syntax, slot references, contracts, effects, common mistakes, and working examples that all parse correctly.

Conformance programs as reference

The conformance suite in tests/conformance/ contains 244 small, self-contained programs — often one per language feature — that serve as minimal working examples (most are fully self-contained; the cross-module programs of Chapters 7–9 import companion _lib/module fixtures). Each positive program must pass its declared verification level (see manifest.json for mappings: parse, check, verify, or run); the thirty-eight negative fixtures (ch02_generic_over_unit_rejected, ch02_map_unit_value_rejected, ch04_let_unit_rejected, ch05_apply_fn_arity, ch05_decreases_float_rejected, ch05_reserved_fn_name_rejected, ch05_reserved_keyword_fn_rejected, ch05_reserved_contextual_keyword_fn_rejected, ch05_reserved_resume_fn_rejected, ch05_where_helper_outer_slot_rejected, ch07_handler_state_body_scope_rejected, ch07_old_outside_ensures_rejected, ch07_state_unit_op_param_read_rejected, ch08_ambiguous_import_adt_rejected, ch08_ambiguous_import_adt_swapped_rejected, ch08_ambiguous_import_rejected, ch08_ambiguous_import_swapped_rejected, ch08_circular_import, ch08_reserved_vera_prefix_rejected, ch08_reserved_vera_prefix_reference_rejected, ch08_reserved_vera_prefix_binder_rejected, ch08_reserved_vera_prefix_effect_rejected, ch08_reserved_vera_prefix_ability_rejected, ch08_reserved_vera_prefix_constructor_rejected, ch08_visibility_private, ch09_builtin_effect_redefinition_rejected, ch09_builtin_redefinition, ch09_ord_adt_rejected, ch09_eq_non_derivable_rejected, ch09_sql_injection_rejected, ch09_sql_placeholder_mismatch_rejected, ch09_sql_placeholder_let_mismatch_rejected, ch09_sql_numbered_placeholder_rejected, ch07_bare_effect_op_rejected, ch06_quantifier_array_domain_rejected, ch07_handler_state_type_mismatch_rejected, ch02_alias_cycle_rejected, ch08_module_prelude_adt_contention_rejected) instead must fail with the E-code in their expected_error field, at the stage their expected_error_stage names — check by default, or compile for a diagnostic the checker accepts and codegen refuses. When you need to see how a specific construct works (e.g. effect handlers, match expressions, closures), check the corresponding conformance program before reading the spec.

Read the full file on GitHub · 218 lines

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. 2d ago First seen · 218 lines · 4,376 tokens per session scan A e2b0001c1fb3

Subscribe to this mod's changes

vera AGENTS.md is an instructions file published in the GitHub repository aallan/vera (411 stars, last pushed 8d ago), licensed MIT. It adds 4,376 tokens to every session, about $0.0219 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 2026-08-30.